Book - Biomicroscopy of the eye 2

From Embryology
Embryology - 24 Sep 2019    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Berliner ML. Biomicroscopy of the Eye - Slit lamp microscopy of the living eye II (1949) Paul B. Hoeber, Inc. Medical Book Department Of Harper & Brothers, New York.

Online Editor  
Mark Hill.jpg
This historic 1949 textbook by Berliner describes biomicroscopy of the human eye. This textbook has been included here mainly for the chapter 24 Developmental Lens Changes.





Modern Notes:

Vision Links: vision | lens | retina | placode | extraocular muscle | cornea | eyelid | vision abnormalities | Student project 1 | Student project 2 | Category:Vision | sensory
Historic Vision 
Historic Embryology: 1906 Eye Embryology | 1907 Development Atlas | 1912 Eye Development | 1912 Nasolacrimal Duct | 1918 Grays Anatomy | 1921 Eye Development | 1922 Optic Primordia | 1925 Eyeball and optic nerve | 1925 Iris | 1927 Oculomotor | 1928 Human Retina | 1928 Retina | 1928 Hyaloid Canal | Historic Disclaimer
Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic Textbook" and "Historic Embryology" appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms and interpretations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Biomicroscopy of the Eye - Slit Lamp Nlicroscopy of the Living Eye Volume II

By

M. L. Berliner, M.D.


Assistant Professor of Clinical Surgery (Ophthalmology, Cornell University Medical College; Associate Attending Ophthahtzologist, New York Hospital; Consulting Ophthalmologist, New York Eye and Ear Infirmary; Instructor in Biomicroscopy, Post-Graduate School, New York Eye and Ear Infirmary; Senior Associate Attending Ophthalmologist, Beth Israel Hospital, New York


With 1233 Illustrations Including 503 In Full Colour

Paul B. Hoeber, Inc. Medical Book Department Of Harper & Brothers, New York


Copyright, 1949, by Paul B. Hoeber, inc., Medical book department of harper & brothers. printed in the united states of america. all rights in this book are reserved. no part of the book may be reproduced in any manner whatsoever without written permission except in the case of brief quotations embodied in critical articles and reviews. for information, address paul b. hoeber, inc., 49 east 33 street, new york, n. y. , e-y


PUBLISHED IN 1949

To

MY WIFE


Contents

Volume I

Preface vii

I. Development of Biomicroscopy

II. The Biomicroscope

The Illuminating System - Optical Characteristics of the Luminous Beam - The Stereoscopic Microscope - Czapski Microscope (Zeiss Model) - Comberg Slit Lamp - Universal Slit Lamp - Simplified Universal Slit Lamp - Poser Biomicroscope - Other Biomicroscopes - Hand Slit Lamps

III. Technique of Biomicroscopy

Preliminary Survey of Eyeball - Illumination of Room - Preparation and Management of the Patient - Adjustment of the Instrument - Stereopsis - Methods of Illumination - Projection of Shadows - Methods of Localization - Procedure for Efficient Biomicroscopy of the Eye

IV. The Normal Conjunctiva

Histology - Blood Supply - Circulation of the Conjunctival Vessels - Technique of Biomicroscopic Examination - Biomicroscopy of the Normal Conjunctiva - Vital Staining of the Conjunctiva

V. Noninflammatory Lesions of the Conjunctiva 154 Developmental Anomalies of the Conjunctiva - Degenerative Changes of the Conjunctiva - Endogenous Pigmentation of the Conjunctiva - Exogenous Pigmentation of the Conjunctiva

VI. Inflammatory and Traumatic Lesions of the Conjunctiva

Conjunctivitis - Acute Conjunctivitis - Subacute and Chronic Conjunctivitis - Allergic Conjunctivitis - Viral Conjunctivitis - Trachoma - Tubercle of the Conjunctiva - Syphilis of the Conjunctiva - Leprosy of the Conjunctiva - Oculoglandular Tularemia - Parinaud’s Oculoglandular Syndrome - Pemphigus of the Conjunctiva (Essential Shrinkage of the Conjunctiva) - Erythema Multiforme (Exudativa) (Hebra) - Erythema Nodosum - Hydroa Vacciniforme - Conjunctivitis Nodosa - Acne Rosacea - Trauma of the Conjunctiva

VIL Tumors of the Conjunctiva

Epithelial Tumors - Neuro-ectodermal Tumors - Tumors of Vascular or Lymphatic Origin (Hemopoietic System) - Granulomatous Tumors (Mesoblastic)

VIII. The Margins of the Eyelids

Biomicroscopy of the Eyelid Margins - Pathologic Alterations of the Margins of the Eyelid - Lacrimal Puncta

IX. Episcleritis and Scleritis

Episcleritis - Scleritis - Scleromalacia Perforans

X. The Normal Cornea; Biomicroscopic Appearance

The Stroma - Corneal Nerves - The Anterior Surface - The Posterior Surface - Optic Section - Vital Staining of the Cornea

XL Developmental Anomalies of the Cornea

Congenital Uniform Diminution of Transparency - Changes in the Size of the Cornea - Abnormalities in Corneal Curvatures - Congenital Opacities of the Cornea - Embryotoxon


XIL Senile Degenerations, Dystrophies, and Pigmentations of the Cornea

Senile Degenerations - Noninflammatory Changes of the Cornea Occurring in Dystrophies - Pigmentation of the Cornea

XIIL Biomicroscopy of Corneal Changes

Epithelial Changes in the Cornea - Vascularization of the Cornea - Nonspecific Changes in Bowman’s Membrane - Alterations in the Stroma Beneath Bowman’s Zone - Alterations in Descemet’s Zone - Increased Visibility of Corneal Nerves - Changes in Corneal Thickness

XIV. Inflammatory Lesions of the Cornea

Inflammations of the Superficial Zone of the Cornea - Inflammation of the Deep Zone (Deep Stroma, Descemet’s Zone and Endothelium)

XV. Traumatic Injuries to the Cornea

Contusions - Abrasions - Wounds - Foreign Bodies in the Cornea - Thermal, Chemical, and Irradiative Injuries

XVI. The Anterior Chamber

Technique of Biomicroscopic Examination of the Anterior Chamber - Thermal Convection Currents in the Aqueous - Congenital Anomalies of the Anterior Chamber - Alterations in the Anterior Chamber Following Trauma - Glass Membranes -

Cysts of the Anterior Chamber - Parasites - Vitreous Prolapse into the Anterior Chamber - Foreign Bodies in the Anterior Chamber - Inflammatory Changes of the Anterior Chamber - Neoplastic Formations - Crystalline Deposits in the Anterior Chamber - Pathologic Variations in the Depth of the Anterior Chamber - Examination of the Chamber Angle with the Biomicroscope


XVIL Gonioscopy H. Saul Sugar

Gonioscopic Technique and Apparatus - Goniometry - Clinical Value of Gonioscopy and Its Limitations - Normal Anatomy of the Angle of the Anterior Chamber - Congenital Alterations in the Anatomy of the Chamber Angle - Pathologic Alterations in the Chamber Angle

Bibliography for Volume I

Index to Volume I

Volume II

XVIII. The Iris

Morphology - Methods of Examination - Biomicroscopic Appearances of the Normal Iris Iris Coloration - Size and Mobility of the Pupil - The Senile Iris


XIX. Congenital Anomalies of the Iris

Anomalies of the Pupillary Pigment Border (Seam) - Defects Principally Involving the Stroma - Anomalies of Pigmentation in the Iris


XX. Inflammation of the Iris . • •

Hvperemia - Exudation in the Anterior ChamTer -Pigmentary Changes -Iris (Stromal) Atrophy (Postinflammatoiy)


SPECIFIC Types of Iritis

Herpetic Iritis - Gonococcal Iritis and Iridocyclitis - Syphilitic Iritis and Iridocyclitis Tuberculous Iritis and Iridocyclitis - Leprosy of the Iris - Heterochromic Iridocyclitis Sympathetic Ophthalmitis -Essential Progressive Atrophy of the Iris - Polycythemia Vera (Vaquez-Osler Disease) -Lymphoma


XXIL


XXIII.


XXVII.


CONTENTS xiu

Traumatic Lesions, Cysts, and Tumors of the

Iris

Traumatic (Mechanical) Lesions - Cysts - Tumors - Leiomyoma - Angiomas - Malignant Melanoma of the Iris - Leukosarcomas - Metastatic Carcinoma of the Iris

The Normal Lens; Biomicroscopic Appearance

The Lens - Technique of Biomicroscopy of the Lens - Relationship of the Morphology of the Lens to its Function of Accommodation - Modifications Associated with Aging - Physiologic Remains of the Tunica Vasculosa Lentis

XXIV. Developmental Lens Changes

Congenital Anomalies of the Lens - Gross Changes in Size, Shape, or Position of the Lens - Developmental Cataracts

XXV. Presenile and Senile Cataract

Coronary Cataract - Senile Cataract - Cortical Cataract - Mature Cataract - Hypermature Cataract - Cupuliform Cataract - Nuclear Cataract

XXVI. Complicated Cataract

Biomicroscopic Appearance of Cataracta Complicata - Cataracts Associated with Endocrine Disorders - Cataract of Myotonia Dystrophia

- Cataract Associated with Mongolian Idiocy

- Cataract Associated with Certain Skin Diseases - Toxic Cataracts - Cataract Associated with Glaucoma - Deformations of the Lens by Local Pressure from Tumors of the Ciliary Body - Spontaneous Dislocation of the Lens - Certain Pathologic Alterations of the Lens Capsule

Injuries to the Lens

Contusion Cataract - Traumatic Cataract Associated with Rupture of the Lens Capsule - Lens Changes Following Penetrating Foreign Bodies


XIV


XXVIIL


XXIX.


XXX.


XXXI.


XXXII.


Radiation Cataract

Heat ("Fire”) Cataract; Infra-red Cataract - Roentgen (X-ray) and Radium Cataract - Biomicroscopic Appearance of X-ray and Radium Cataract - Electric Cataract (Cataracts from Lightning and Electric Shock)

Secondary Cataract Secondar)'^ Membrane racta Secundaria


After-cataract - Cata

The Zonule

General Considerations - The Zonule in Certain Hereditary and Congenital Anomalies - Pathologic Alterations of the Zonule Following Inflammation - Traumatic Alterations of the Zonule

The Vitreous

General Considerations - Technique of Biomicroscopic Examination of the Vitreous - Biomicroscopic Appearance of the Normal Vitreous - Special Methods Devised for the Examination of the Vitreous - Congenital Anomalies

Biomicroscopy of Vitreous Opacities

General Considerations - Senile and Myopic Alterations - Synchysis Scintillans and Asteroid H^^alosis - Changes in Inflammation - Tumors Affecting the Vitreous - Traumatic Injuries to the Vitreous - Intra-ocular Parasites


Bibliography for Volume II Index to Volume II


18 The Iris

The importance of careful biomicroscopy of the iris cannot be overemphasized. The iris is composed of both ectodermal and mesodermal derivatives, and all the defects, both developmental and acquired, that affect such tissues are observed. From the standpoint of genetics, iris studies have proved extremely fruitful. The classical examples of hereditary iris color variations, so ably analyzed by Davenport according to Mendel’s law, are discussed later. Vogt, in his observations on uniovular (identical) twins, has brought out conclusive evidence that certain changes, e.g., senile disturbances of the pupillary pigment border and stroma, can be explained only on a genetic basis. Biomicroscopy of the iris can disclose early many intrinsic changes attributable to abiotrophy and senility. Because of the frequency of iridic involvement in systemic disease, its value in the study of such pathologic complications is inestimable. From the standpoint of function there is no better method than biomicroscopy for the study of pupillar}'- mobility. Frequently a pupil that appears rigid by ordinary examination will disclose a local or sectorlike reaction to light. Together with gonioscopy this method affords the best means of observing the role that the iris plays in the interference with the intra-ocular pressure mechanism.


The anterior iris face, with its markings exposed like the dial of a clock, lends itself ideally to biomicroscopic inspection, except in the extreme periphery where it is hidden by the overlapping sclera. Even before the days of biomicroscopy, the ease with which the surface of the living iris could be inspected, by means of the loupe or binocular microscope, led to very accurate descriptions of its architecture or surface markings, its luster and color. The structure of the iris, composed of tissue derived both from ectodermal and mesodermal elements, is optically heterogeneous in character." Normally, the complex structure retards internal illumination or retro-illumination (transillumination) of its substance and thus renders it more obstructive to these types of illumination than do the tissues of the so-called transparent ocular media.


Gonioscopy reveals parts of this hidden portion (see Volume I, Chapter 17).


PLATE XLI

Fig. 1. Normal brown iris, illustrating the pigment seam, crypts, contraction furrows. (Direct focal illumination.)

Fig. z. Normal blue iris, illustrating surface markings. (Direct focal illumination.)

Fig. 3. Normal blue iris. (As viewed by optic section.)

Fig. 4. Normal blue iris, showing physiologic rarefaction below.

Fig. j. High-power view of Figure 4.

Fig. 6 . Blood vessels seen in normal iris.

Fig. 7. Blue iris as seen by daylight.

Fig. 8. Same iris as shown in Figure 7 observed biomicroscopically in diffuse illumination. Brownish color is due to reflection from the posterior pigmented surface.

Fig. 9. Tongue of iris stroma adhering to the seam. (Pupillary pigment border.)


Owing to its heavily pigmented posterior face it is impossible to transilluminate or retro-illuminate even the normal blue or gray iris with light reflected from the lens or fundus. The added surface pigmentation of the normal brown iris further obstructs this type of illumination. Only albinotic or atrophic irides transmit such light readily. However, employing the narrow beam of direct focal illumination in light blue or gray irides, it is possible, within limits, to obtain an optic section through their substance. Also by indirect lateral illumination (a form of scatter) due to internal dispersion, the sphincter or such changes as hemorrhages (suggilation) , which usually are not visible in direct focal or diffuse light, may be observed within the tissue of the iris. The normal variations in coloring and architecture are so multitudinous (no two irides are ever alike) that the necessity for observing many cases is evident. Not only are there variations in coloring and architecture in different persons but even in the two eyes of the same person, and a given iris undergoes changes in color and structure with the passage of time from childhood to senility.


Both blue and brown irides may reveal well-developed surface markings (Plates XLI, figs, i, 2; XLII, figs, i, 2, 3, 4, 5). But some blue-gray irides have such a compact structure that relatively few markings are visible. Heavily pigmented brown irides may present a uniformly structureless spongelike surface without trabeculae. In some of these cases a sharp line may indicate the declination (lesser circle) of the pupillary zone toward the pupillary margin. Even in the irides of Negroes, the ciliary portion may - disclose this type of uniform spongy structure while the pupillary zone of the same iris may show a trabecular design with many crypts. When the surface of a dark brown spongy type of iris is studied under high power, an intricate and delicate pigmented network can just be made out with difficulty. This network may represent starlike branchings of the melanophores. The morphology and biomicroscopic appearances will now be considered in more detail.


In comparison, the cornea, lens, and vitreous, composed of "gel-Iike” transparent tissue, can almost be considered optically homogenous. Ordinarj’ clear glass would be an example of a substance having the property of true optical homogeneity.


Morphology

Histologically, proceeding internally, the iris may be divided into five layei's: (i) endothelium; (2) anterior border layer; (3) vessel layer; (4) dilator pupillae, composed of (a) posterior border lamella and (b) pigmented spindle cells; and (5) pigmented epithelium (Fig. 306).


End of helium. Although difficult to demonstrate in preparations, the endothelium is generally accepted as being present in the form of a poorly defined noncontinuous layer. It is important to note that it does not cover the openings of the crypts and that it is poorly developed in the neighborhood of the lesser circle.


Anterior Border Layer. The anterior border layer is thin, dense and avascular, composed chiefly of melanophores (in the brown iris), and sparsely interspersed collagenous fibrillae. This layer is missing at the entrance of the crypts and is thin over the floor of the contraction furrows. Its density and pigment content determine the color of the iris, Salzmann states: "Blue irides have a delicate border layer and almost unpigmented cells; brown irides have a thick border layer and very heavily pigmented cells.” At the periphery, the anterior border layer and the underlying stroma are thrown into folds (contraction furrows). The anterior border layer is thinnest in the troughs of these folds.


Vessel Layer. The vessel layer forms the larger part of the iris stroma and contains numerous larger vessels (most of them coursing in a meridional direction) and nerve plexuses. The stroma itself consists mainly of delicate loose fibrillae branching chiefly in a meridional direction. In the pupillary zone and toward the periphery of the ciliary zone many of the fibrillae take a circumferential direction. The stroma also contains melanophores, clump cells (Koganei), and the sphincter, the latter two being derived embryologically from the posterior or ectodermal layers. Both pupillary zone and ciliary zones contain crypts. They appear deeper, larger, and more undermined in the pupillary zone. The sphincter lying in the deep stroma has the form of an annular band about i mm. wide. Its border is intimately connected with the pigment of the pupillary border (seam) while its peripheral boundaries and under surface have direct connection with the underlying dilator pupillae.


  • For a more detailed discussion of the anatomy and histology of the iris, the reader is referred to Salzmann's "Anatomy and Histology of the Human Eyeball



Fig. 306. Histologic Section of iris showing its layers, a. Pupillary zone of the iris, meridional section, X 60. r'G’, anterior border layer (with endothelium) ; G, vessel layer; Dr, dilator pupillae; P, pigrnent epithelium; Sph, sphincter pupillae; e, radiation of the dilatator into the sphincter from behind; Ps, pigment seam of the pupillary border; K, clump cells. (After Salzmann.) b. Ectodermal layers of the posterior iris surface, transverse section, bleached, X 330. S/r, stroma of the vessel layer of the iris; Sph, sphincter pupillae; K, clump cell; D/, dilator pupillae; P, pigment epithelium. (After Salzmann.)


The stromal and vessel layer is thinnest at the root of the iris and is thickest in the pupillary zone near the lesser circle. The latter area (near the sphincter) is the most highly vascularized, and it is only here, according to Kruckmannj'^^* that a real capillary network exists.


Fig. 307. Relief of a posterior iris surface, under reflected light, X9. rF, radial furrows of the pupillary zone; sF, structural furrows; cF, circular furrows; C, anterior border of the corona ciliaris. (After Salzmann.)


In other parts there are some small capillaries but not in the form of a continuous net. This fact is evidenced under certain pathologic conditions, e.g., roseolae in which congestion of the superficial capillaries appears as disconnected stars or rosettes.


Dilator Pupillae. The dilator pupillae is composed of a strongly fused double layer, the deeper being pigmented. It lines the under surface of the vessel layer, extending from the iris root to the edge of the sphincter. Embryologically the dilator muscle is derived from the layer of pigmented epithelium.


Pigmented Epithelium. The pigmented epithelium is the layer of cylindric cells lining the posterior face of the iris. These cells are so densely pigmented that details concerning them can only be seen in depigmented preparations. This layer represents the continuation of retinal-derived ciliary epithelium over the posterior iris surface. In meridional section one sees a profile of the system of circular furrows characteristic of the markings of the posterior iris surface. These markings can best be seen by inspection of a flat (frontal) anatomic preparation of the entire dark brown or black surface. Both radial and circular markings or folds can be distinguished on this posterior aspect. The latter are much finer and are found only in the region of the structural-furrow system where they cross them in a regular manner. There are two systems of radial folds; One is composed of fine, shallow grooves in the pigmented epithelium, which extend to the pupillary border and continue around it (Fig. 307). This produces the normal beading (ruff) or pupillary excrescences (seen from in front) of the pupillary border. In the second, the structural furrows are deeper at first and then flatten out as they approach the ciliary border. They begin about o. 5 mm. from the end of the pupillary system of folds. This design on the posterior surface of the iris is of interest to the biomicroscopist because its existence may explain certain alterations found on the lens capsule, e.g., detachment of superficial lamellae of the lens capsule (page 1223).


Methods of Examination

Diffuse Illmmation. The very nature of the iris structure enhances its examination in diffuse illumination. The whole surface may be viewed in the light of the pre- or postfocal (unfocused) beam. In order to obtain a field large enough to include the entire iris surface, it is necessary to use low magnification. In this way it is possible to make a survey of the entire iris surface (Plate XLII, figs. 1-8). At a glance not only the normal or any gross structural or color changes of the stroma but also the iris mobility may be seen. This form of illumination is recommended for use at the beginning of all biomicroscopic examinations of the iris.

It may be advisable to employ a miotic in certain cases where extreme "stretching-out" of the iris is desirable. This may be of value in sensitive subjects by diminishing the amount of light which enters the pupil.


PLATE XLII


Fig. I. Dark brown iris. (Diffuse illumination.) Observe paucity of surface markings and note the lighter color in the bottom of the crypts and contraction furrows.

Fig. 2. Blue iris, illustrating the delicate trabecular structure.

Fig. 3. Grey iris.

Fig. 4. Blue iris. Large crypts. Well-formed lesser circle.

Fig. 5. Brown iris with well-formed lesser circle. Wolffian bodies.

Fig. 6. Iris bicolor.

Fig. 7. Piebald iris.

Fig. 8. Iris bicolor. Superficial leaf is brownish. Deeper leaf, greenish blue.


Direct Focal Illumination. When the focal point of the beam is directed obliquely toward the iris, an area of highly illuminated surface is seen, corresponding in shape and size to that of the slit opening (Fig. 308). With the widest opening of the slit, the highest intensity of illumination will result (Plate XLI, figs, i, 2). It is generally advisable to have the focused light beam directed from the temporal side and to employ a wide angle (from 45 degrees to 90 degrees) between the axes of illumination and observation. (Because of the localized area of illumination higher magnifications for observation can be employed.) However, contrary to what occurs in the cornea and lens, no sharp block (parallelepiped or wedge) will form. Such an optical phenomenon can only occur (as mentioned before) in tissue that transmits light more readily.


Fig. 308. Diagram illustrating the technique of direct focal illumination of the iris. 7 , axis of illumination; O, axis of observation.


Koeppe has recommended the use of a yellow filter which helps to cut down on dazzling and tends to bring out fine details in greater relief. He found also that the blue or red-free filter assists in differentiating between light bfown pigment (melanophoric.>) and dark brown pigment (retinal). With this filter the ydlow color of the light brown pigment is marked so that it becomes indistinguishable from the surrounding background, while dark brown pigment appears black.


Depending on the texture of the iris, some of the light enters the stroma and permits the visualization of certain details. This is particularly true of blue and gray and of certain brown irides (where the trabecular structure is visible) . In many dark brown irides the surface is so densely pigmented that it appears smooth and spongy. In these cases it may be impossible, except for the pigment excrescences at the pupillary border and the contraction furrows, to discern surface markings or any of the trabeculae. Here, a thickening in the region of the lesser circle will be present with a sudden posterior or inward declination of the tissue axially toward the pupillary margin, indicating the pupillary zone. A more gradual sloping of the ciliary zone to the periphery may also be perceived. When crypts are present even in darkest brown irides, the absence of the anterior border layers over their openings may allow inspection of the deeper leaf which, despite the underlying retinal pigment layer, may appear lighter brown or yellow in color.


An inspection of the entire iris should be made. Until the patient has become accustomed to the brilliancy of light of the focal beam, it is advisable first to inspect the peripheral regions and then the pupillary zone because, as the beam approaches the pupillary pigment border, some of the light of necessity passes into the pupil and causes dazzling. Hence, as previously mentioned, the advisability of employing a wide angle between observation and illumination, since with a wide angle more light is directed to the less sensitive parts of the retina. As the pupillary zone is approached not only the region of the lesser circle (frill or collarette) but also the pupillary pigmented excrescences and intervening tissue may be studied to a degree impossible by any other methods. The extreme mobility of the pupillary zone under the influence of the light beam is a striking feature. In lightly colored irides, movements of individual fibers of the deeper layer may be seen following the actions of the sphincter.


In pathologic states, as will be seen later, the method of direct focal illumination will disclose a host of structural tissue variations as well as alterations due to exudative, vascular, atrophic, and neoplastic changes.


Optic Section. With the narrow beam it is possible, in many instances and within certain limits, to obtain an optic section of the iris tissue (Plate XLI, fig. 3). The exceptions, of course, depend on the density and pigmentation of the stromal tissue. The blue or lightly pigmented iris lends itself best to this form of illumination. Where the narrow beam first contacts the iris surface, a delicate line appears (impact line) . This probably represents the surface of the anterior border layer. Immediately below it are the fibers of the trabeculae. At times, when the trabeculae are of loose construction, single or branched fluffy trabecular fibers seem to arch up and contact this impact line. The trabeculae are always enmeshed and connected to one another by diaphanous, almost invisible ground tissue. Occasionally in light colored irides a vessel-bearing trabecula may be seen. In this case the center of the fiber consists of a delicate reddish line. In some cases large or small rounded or elliptical spaces are formed between the fibers. These spaces are situated below the surface and differ from crypts in that they do not have surface openings, since even the most superficially placed ones are always covered by the surface impact line. On the other hand, no tissue is visible over the openings of a real crypt, as indicated by the absence of an impact line. Koeppe, using a yellow filter with indirect illumination, has described a delicate subsurface system of furrows or cavities corresponding to the infoldings of the surface. He stated that they are seen in light irides, especially in older individuals, and that they have a "frosted” appearance. He interpreted them as being lymph-containing spaces which he claimed resulted in the aged from regeneration into vacuoles and cavities of a subendothelial system of vesicles.

I have been unable to identify these structures.

It is impossible to tell where the superficial leaf or layer ends and where the deeper leaf starts. One has the impression, however, that the structure of the deeper leaf is more compact. Just under the deeper leaf is the dark yellowish or brown reflection of the posterior retinal pigment layer. Even when a deep large crypt extends through the entire thickness of the stroma or when there is marked stromal atrophy, it is impossible by optic section to identify the individual layers of the highly pigmented dilator and the underlying epithelium. However, at times it is possible to see a faint radial grayish striation of the surface of the exposed pigmented layer; anatomically this represents the part of the dilator known as the posterior border lamellae. It is composed of a compressed layer of spindle-shaped processes derived from and indistinguishably connected with the deeper situated epithelial cells. However, in the lighter colored irides the sphincter can usually be seen by optic section; this is true not only of its outer edge but also of its surface, which generally has a yellowish appearance (Plate XLII).



Fig. 309. Diagram illustrating the technique of retro-illumination of the iris.



Ketro-ilhnnmation. Since it is impossible to retro-illuminate the normal iris, this method can only be used for the detection of pathologic states. The absence of retro-illumination does not exclude pathology of the iris but when present its significance is irrefutable.


Biomicroscopically, the iris can only be satisfactorily retroilluminated by means of diapupillary illumination, that is, by light reflected back from the lens (Fig. 309). This is accomplished by directing the beam obliquely through the lens via the pupil. Because of the fact that there is a high degree of internal reflection and dispersion in the lens, considerable light radiates anteriorly toward the posterior iris surface. If the posterior pigmented surface is normal most of the light is absorbed. Hoiuever, when the retinal pigment is absent or has been destroyed, e.g., in atrophic states, varying degrees of this reflected light may pass throngh the defective areas to the eye of the observer. Retro-illumination of an albinotic iris is strikingly beautiful (Plate XL VI, figs, i, 2). This method is not applicable in aphakia since the vitreous is a poor reflector. Internal reflection in the lens increases with age and this is most marked when the lens is cataractous. Retro-illumination early discloses presenile or senile atrophy of the pupillary border - atrophy of the stroma and posterior pigment layers, ruptures or tears, holes, or dehiscences. Frequently cysts and efflorescences (especially at the pupillary border) can be retro-illuminated. Because of the required increased obliquity of the beam’s direction as it enters the pupil, only opposite sides of the iris will be adequately retro-illuminated. For example, to retro-illuminate the temporal side of the iris, the light must be directed into the pupil from the patient's nasal side and vice versa. With experience, the observer almost intuitively looks at the darkened iris as the focused beam enters the lens and, with perhaps slight oscillatory movements of the light, will immediately note any transilluminable or rarefied areas in the iris. These will appear whitish, grayish, or yellowish (depending on the color of the light reflected back from the lens) in contrast to the darkened uninvolved adjacent iris tissue.


Diapupillary Transilhimination or Retro-illnmination of the Iris in Fiindiis Reflex. Comparable to what occurs with the ophthalmoscope and with diascleral illumination (diaphanoscopy) it is possible under certain conditions to observe the red glow of the fundus


To a lesser degree, the iris may be retro-illuminated by light reflected from the fundus.

reflex when the focused beam of the biomicroscope passes into the eye via the pupil (Fig. 310). When the iris is normal only the glow in the pupil will be observed. However, defects in the iris resulting from atrophy, holes, dehiscences, and even minute depigmentations of the posterior retinal layer will permit passage of this light, which appears reddish in contrast to the grayish hue seen in ordinary retroillumination.


Fig. 310. Diagram illustrating the technique of diapupillary transillumination of the iris by light reflected from the fundus.


The direction and course of the emergent rays will vary depending on the refractive condition of the eye. In order to observe these rays and the red glow which they cause it is necessary for the observer’s direction of gaze to correspond as closely as possible to the direction of the emergent light. In other words, the head and e)^e of the observer must be as close as possible to the arm of the illuminating system. This corresponds to the technic of gonioscopy and biomicroscopy of the fundus. Although the employment of the Koeppe or Kleefeld mirror and a monobjective microscope assists in narrowing the angle between observation and illumination, better results are obtained, as pointed out by Davidson,®”® by dispensing with the microscope and using the unaided eye. To increase the brilliance of the reflex, the loo-mm. illuminating lens is preferable to the ordinary 70-mm. In the Poser instrument greater depth of focus can be secured by using the diaphragms. The brilliance of the fundal reflex also depends on the strength of the light source. Overloading the nitra lamp above the usual 8 volts or the use of an arc lamp is of advantage. Davidson states “the maximum intensity is secured by focusing the beam for the plane of the pupil. The beam then occupies only a small portion of the pupil, the free portion giving a fundus reflex. An overloaded voltage is necessary to secure the requisite intensity and the observer’s light sense should be enhanced by dark adaptation. A small pupil is preferable in looking for defects which may disappear in the iris folds. The visibility of the iris defects seems little affected by the direction of the beam; that is, whether it is directed to the same or opposite side of the sector involved.


Proximal {Indirect) Illumination. When the focused beam falls on the iris, some of the light scatters within the neighboring stroma itself, resulting in a form of dark field illumination. For example, when the beam is focused near the pupillary edge in a lightly pigmented or blue iris and moved peripherally, ever so slightly, a portion of the crescentic outer margin of the sphincter can be observed. (See Vol. I, Figs. 99, 100.) Normally, the axial edge of the muscle is connected so intimately with the pigmented pupillary excrescences (seam) that it is not visible. The outlines of crypts, atrophic areas, and perforations can also be identified by this form of illumination.


See Volume I, page 48.


Moreover, it is useful in the study of cysts and tumors. Frequently, following trauma, a reddish hue can be discerned in the stroma owing to the presence of bloody suggilation - a, phenomenon often overlooked and invisible by other methods. The incident angle of the beam should be a little wider than that used in direct focal illumination. Using the indirect method together with extremely high magnification, Koeppe has claimed that it is possible to make out in light colored irides, especially in older persons, a subendothelial system of vesicles and vacuolar lymph spaces. He described these in great detail stating that this system forms a glasslike layer having a frosted appearance. However, Koeppe’s views on this subject have not been substantiated by other workers.


Fig. 31 1. Diagram illustrating the appearance of the iris when viewed by corneoscleral scatter.


Iris Scatter. Transscleral and translimbal (corneal) illumination of the iris is entirely feasible providing the examining room is very dark and the light source is of high intensity. The overloaded nitra


bulb (iz to 14 volts) or better, an arc lamp, is advantageous. B) slightly moving the light over the cornea a place may be found where the same and the opposite side of the iris surface (especially the periphery) are caused to glow (Fig. 3 1 1 ) . The light is reflected from an illuminated arc of the posterior corneal surface. By this method an unsurpassed plastic impression of the configuration and molding of the iris is obtained. The iris contours, depressions, tumors, or discontinuities are displayed in relief like an itaglio. With the stronger illuminants, holes and other defects, such as are seen by diapupillary illumination, may become visible. This method corresponds to sclerotic scatter (see Vol. I) employed in the examination of the cornea. In the iris it affords a view of its entire anterior face similar to that provided by diffuse illumination. With the slit aperture wide open, in order to obtain maximum intensity of light, the beam is focused at the corneoscleral junction. The iris is then observed with the microscope, using low or middle magnifications.


Specular Keflection. Contrar)^ to what occurs on the smooth surfaces of the cornea and lens it is not possible to obtain any zones of specular reflection in the iris. Not only does the iris absorb so much light, but the very nature of its surface precludes any sizable degree of mirror (regular) reflection which is necessary for the production of such zones. Consequently this method cannot be applied to the biomicroscopic study of the iris.

Biomicroscopic Appearances of the Normal Iris

For our purpose the iris may be considered as being formed of two main layers (Fig. 312) :

I. The anterior or mesodermal layer: composed of

A. Anterior

(superficial) leaves, which together form the anterior face

B. Posterior of the iris.

(deeper)

II. The posterior or ectodermal layers (the posterior face) is com The designs .ind configur.-itions formed by the iris structures, as seen from in front, arcknown .-IS the "markings of tlie iris."


Fig. 312. Surface markings of the iris projected on its histologic section (diagrammatic), r, Pupillary pigment border (seam); 2, sphincter area; 5, lesser circle (collarette or frill); crypt; 3, freckle; 6, 7, 5 , contraction furrows.

posed of dilator and posterior pigment epithelium. It is seen as one layer and can only occasionally be differentiated in normal eyes with the biomicroscope, e.g., in the bottom of a deep crypt (Plate XLIII, fig. j).


THE ANTERIOR LAYER

The anterior layer is composed of two leaves derived from mesodermal tissue - superficial and deep. This fact was first discovered by Fuchs. Together both these layers form the iris stroma. The stroma is composed of connective tissue fibers, vessels, and pigmented cells. When a blue or gray iris is observed, it is seen to be built up of fibers, or trabeculae whose main direction is radial - converging toward the pupil. This is especially true in the ciliary region, where the trabeculae are derived from thick vascular trunks which enter the iris at regular distances.


In some cases interwoven or interlaced trabecular branches may run obliquely or even concentric to the pupillary margin. These, however, are best seen only in atrophic irides or when certain defects such as ruptures reveal the deeper layers. In blue or lightly colored irides, especially in the ciliary zone, these radial fibers have a wavy or even corkscrew appearance. They really are the blood vessels of the iris, which appear opaque and apparently bloodless because of a thick adventitia, which is enmeshed by a delicate veiling of stromal tissue, resembling an insulated electric wire. Overdevelopment of the anterior leaf in the region of the lesser circle may obscure the striation. Except in the region of the lesser circle, where a number of larger trabeculae condense (frill) and almost turn at right angles to run concentrically, trabeculae tend to run more or less parallel in a radial manner. With higher powers it will be seen that they frequently branch dichotomously and at times give off branches which cross neighboring trabeculae and run obliquely or even somewhat concentrically for a short distance. Such branchings are best observed in the ciliary region and near the pupillary zone. Occasionally, in blue or gray irides, by using a blue filter and strong direct light, one can make out a dark central channel in a larger trabecula.


PLATE XLIII


Fig. I. Marked senile atrophy of the pupillary border.

Fig. 2. Displaced pigment excrescence on the surface of the iris below.

Fig. 3. Senile atrophy of the deeper leaf of the iris with marked rarefaction of the stroma.

Fig. 4. Senile hypertrophy of the pigment excrescences of the pigment border.

Fig. 5 . Senile rarefaction and atrophy of the pupillary iris border. Note sphincter.

Fig. 6 . Iris bicolor. Ciliary portion of the iris is gray while the pupillary portion is brown.

Fig. 7. Iris bicolor. Ciliary portion of the iris is brown while the pupillary portion is gray.


This probably is the blood column. If the stroma is very light, occasionally one may, in addition, see a fine pink vessel traversing the trabeculae (Plate XLI, fig. 6). These vessels are enmeshed in the soft cottonlike tissue of the stroma and usually are found in the region of the lesser circle and in the periphery. However, one is less likely to see them when the trabeculae of the superficial leaf are overdeveloped.


Biomicroscopically the visibility of these structures will vary from case to case, depending on the design or compactness of the tissue and on the amount of pigmentation present. As a rule the light colored iris has a more delicate and fragile architecture than the dark (Plates XLI; XLII) . The structure of the anterior layers of the gray iris is frequently looser than that of the blue and consequently may allow of better inspection of the deeper leaf. In some blue irides the superficial layer of radial fibers are very compact, being without crypts or other sharp lines of demarcation, such as, frills or contraction furrows. Brown irides may also display varieties of structure compactness. In some, a marked and beautiful design of trabecular structure may be seen in which the frill and superficial trabeculae stand out sharply, even as strong thick bands (Plate XLII, fig. 5 ) . Some of the larger trabecular bundles may subdivide into smaller strands. The finest strands or threads are those which cross over or subdivide the crypts. However, the surface pigmentation and fiber structure may be so compact as to give the dark brown iris a uniform velvety or spongy appearance to a degree that no surface markings may be visible (nontrabecular construction) (Plate XLII, fig. I ) . It is not possible biomicroscopically, even with the highest power, to discern any structure on the iris surface, which might be interpreted as an endothelial cover. With the optic section the anterior border layer is discerned as a thin solid line.


Koeppe described the iris tmbeculae in gre.at detail, according to their size, brandlings, and as to whether or not they had visible vessels. He was able to discern many more vessels bearing trabeculae than I have. My impression is that in light colored irides, especially in the aged, more actual vessel-bearing trabeculae can be seen than in the young but on the whole they are only occasional. When using the highest power, i.e., over 70 X, great enlargement of the structures is obtained but at the expense of clarity, since even with the brightest light the enlarged images appear blurred.


In light blue irides with 40 X magnification or more, using indirect illumination, I have been able to make out what appears to be a fine stippling in the dehcate cottonlike connective tissue supporting the superficial trabeculae. But even with still higher magnification I have not been able to convince myself that these were actual vesicles such as Koeppe described.


The superficial leaf of the anterior layer of the stroma starts at the periphery and extends to the lesser circle (cir cuius minor), ending in an irregular zigzag line or frill that runs irregularly concentric to the pupil. This line may be found at varying distances from the pupillary margin but usually closer to the sphincter edge than to the periphery. Although it frequently appears as a single line, in reahty it consists of many bowed trabeculae bound together by connective tissue. The superficial leaf is usually so intimately connected with the underlying deeper leaf that except in certain types of irides it is not possible to distinguish it as a separate layer.'*' But at its termination at the lesser circle it may be separated from the deeper leaf by a frontal cleft, known as "Fuchs’ cleft.” This cleft can easily be seen in the partially dilated pupil where the pupillary zone begins to slide under the frill, which stands out as a more or less sharp ridge (Fig. 313 B) . In most cases there are direct connections between the frill and the radiating fibers of the deeper leaf of the pupillary zone. These trabeculae extend to the pigment border of the pupillary margin. With higher magnification it will be seen that although most of these trabeculae run axially to the pupillary margin, dichotomous branchings often occur in which some of the smaller branches tend to meet divisions from other trabeculae; in so doing they take a course somewhat concentric to the pupil. Near the pupillary margin an occasional trabecula may loop backward to join another radial branch.


It should be remembered that embryologically the superficial leaf is composed of radial blood vessels, supported by connective tissue,

Congenital splitting of these two layers has been reported by Waardenburg. It was transmitted from a mother to three children as a dominant hereditary characteristic. Such a change can also occur as a senile degeneration. (See page 777. Also see Plate III, fig. 5.)


which form circular arcades in the region of the lesser circle. The convexity of the arcades faces the pupil (Fig. 313) . From this circle terminal arcades of vessels, also supported b) a delicate film of mesoderm, convergently extend over the pupillary opening to form


Fig. 313. Congenital vascular arcades in the region of pupil. (After Ida Mann.)


the pupillary membrane. Hence, the frequently seen postnatal remnants of the pupillary membrane are always connected (at least at one end) with the frill. (See Vol I, Plate XXXVIII, figs, i, 2, 3, 4, '6.) From the sixth month of fetal life the vessels of the pupillary membrane no longer grow but instead begin to atrophy and finally disappear, at the same time the vessel arcade of the lesser circle continues to develop with the remainder of the Iris. The vessels of this arcade have a greater lumen than the intervening or deeper vessels, and later they appear of heavier structure. Hence, the frill may be considered a form of redundant hypertrophic rudiment of the fetal iris vessels of the lesser circle; consequent^ the architecture of the frill and the superficial leaf repeats the fetal vascular design. Biomicroscopically, the appearance of this zone varies so much from one case to another that it is impossible to give an)'^ systematic description of it. At times, even in adults, with strong illumination (arc source) blood in the form of fragmented columns ma}’^ be seen in certain parts of the frill itself. That the superficial leaf is really a definite la^^er is proven by the fact that it may be missing,

or if present may become detached, in which case it has even been seen to float freely in the anterior chamber.


In cases in which no frill is found it must be assumed that resorption of the vessels was complete and that the secondary hypertrophy of the vascular remains at this point did not occur. In others the frill may be so interwoven with neighboring fibers as to be invisible or, frequently, strands flush with the surface may lose themselves in the direction of the pupil (Plate XLI, fig. 9). The frill in certain instances (e.g., in lighter colored irides) may be so well developed as to constitute a hypertroph)^ Vogt described such a case in which there was also a tlfich and strong extension similar to a pupillary membrane. These fibers are very expansive and do not tear with mydriasis. In such cases a weblike structure frequently is seen bridging over the angles formed by the junction or anastomoses of the trabeculae. This, together with fusion of the trabeculae into bundles, may give these structures at the lesser circle an appearance of giant size (Plate XLII, fig. j). Here they may flatten and spread out fanwise or appear like stars.

There are cases in which the frill extends over to or is attached to the pigment border of the pupillary margin. In others, it may be found near the chamber angle. Frequentl)^, it happens that the frill is only well developed for a small distance, and in the remaining iris circumference only an unmarked raised area indicates the beginning of the sloped pupillary zone.

Kriickvmiin-Wdjflhi bodies. At times nodular structures may form in the region of the collarette. More commonly similar knoblike condensations (brown, yellowish, or whitish in color) may be found at the peripherj near the limbus (Plate XLII, fig. 5). These nodehke structures lie between the contraction furrows and with mydriasis they assume a concentric arrangement owing to deepening of the furrows. Deepening of the contraction furrows also tends to exaggerate their height so that the)^ resemble mounds bordered by troughs. The color of these nodes vary with iris coloration. In very dark brown irides they appear darker since condensations of the superficial iris layer results in a localized heaping together of the melanophores (similar to nevi) while in irides of lighter color, owing to the sparseness of pigment tissue, these condensations appear yellow or even whitish. They are best seen by indirect light and when present usually appear in both eyes. In cases of iridocyclitis they have been incorrectly interpreted as inflammator}'^ nodules. Comparison with the unaffected eye will serve to avoid such an error. These normal tissue nodules were described by Kriickmann and Wofflin and are best seen by iris scatter or indirect illumination.


Crypts (holes or openings) in the stroma are usually found in the superficial leaf near the region of the frill; however, they may occur in the far periphery (Fuchs) or in the deeper leaf of the pupillary zone (Plate XLII, figs. 4, 5, 7). Crypts probably result either from defects or from localized areas of fetal or postfetal atrophy, involving not only the superficial leaf but also the deep one as well. They are only found in man. Even other higher mammals, such as monkeys, do not show them. Crypts are seen in both blue and brown irides but in the typical spongy type of Negro iris, if present, they are chiefly found in the pupillary zone. Crypts of the peripheral ciliary zone are usually smaller and shallower than those of the pupillary area or in the region of the frill.


When the structure of the deeper leaf is seen in the bottom of a crypt it appears lighter in color in direct focal illumination than the neighboring surface iris which normally bears most of the stromal pigment; in deep crypts and especially in those which extend entirely through the posterior leaf, the dark posterior retinal pigment layer is seen. By daylight, however, a crypt may appear darker than the surrounding tissue owing to the fact that its base lies in the shadow cast by its steep side walls. This darkening effect will also be augmented by the darker color of the posterior surface of the iris when the depth of the crypt extends down to it. Occasionally in large open crypts trabeculae bearing small radiating vessels containing blood may be seen in the depths. Crypts may be subdivided by thick or thin tissue threads passing over their openings. This may also occur within the crypt giving it a layered appearance. The walls of a crypt show the same structure as the stroma. The larger crypts are rhomboidal in shape and are usually bordered by large trabeculae. With dilation of the pupil these tend to flatten out and take a direction concentric to the pupil. The smaller crypts have a more circular opening. In light colored irides Koeppe described crypts of the third magnitude, i.e., crypts so small that they could be seen only with magnifications of i oo X .


The anterior border layer is usually entirely missing over the openings of crypts and the deeper stroma itself, seen in the depths, is less pigmented. However, in some cases, as previously pointed out, an occasional trabecula may pass over the opening or within the depths of a crypt. Such fibers vary in size and at times are merely threadlike. Except for this, even after employing the narrowest possible optic section and high power, I have never been able to find any covering over crypt openings that might be interpreted as an endothelial or anterior border layer.


Contraction furrows are seen in the surface of the iris peripherally to the region corresponding to the middle half of the ciliary zone (Plate XLI, £g. i ) . These are sharply outlined grooves, running concentric to the peripheral iris border and probably result from pupillary movements. An individual furrow may extend a quarter or half way around the iris but it never completely encircles the iris (Fig. 312). Similar to the lines on the palms of the hands, which deepen when the hand is flexed and flatten out with extension, the furrows deepen with m^'^driasis and flatten out with miosis. As is the case in crypts, the troughs of the furrows in a brown iris, especiall}'" in children, are lighter in color than the surrounding areas. This may be caused b}*" the fact that anatomically the anterior border layer is thinner in the bottom of the furrow, hence there is less pigment. Mawas and Kriickmann both believe that the lessened pigmentation results from mechanical changes, while Vogt explains this as an anomaly of development. In very light colored irides, owing to the paucity of stromal pigment, the bottom of the furrows have a dark appearance. Fine radial strands of the superficial leaf ma^ be seen in the furrows of heavily pigmented irides.


The posterior or deep leaf of the anterior laj^'er is covered b) the superficial leaf, from its periphery to the frill (ciliary portion of iris), from here to the pupillary margin the stroma is seen to be formed mainly by the deeper leaf and lies exposed to view. When not too compactly obscured by pigment, this deep stroma can be observed as thin, stretched trabeculae, running radially and at times slightly eccentrically (Plate XLII, figs. 5, 6 , 7). As stated before it is not always possible to identif}'^ circular fibers (i.e., those concentric to the pupil) : occasionally, particularly in the normal blue or gray iris, radial vessels may be seen in this area. In miosis, in cases in which posterior synechiae exist, or following iris atroph)'", trabeculae of the deep leaf may be stretched tautly between the frill and the pupillary margin. However, the fibers of the adjoining superficial leaf may reveal no such tension - remaining wavy and relaxed, indicating the independence of this leaf to changes occurring beneath it. In other words, the superficial leaf will only act passively with the movements of the deeper one, which is more intimately connected with the sphincter and dilator, structurally and functionally.

In the ciliary zone the structure of the deeper leaf can be seen only through openings or crypts in the superficial leaf. When the structure of the deeper leaf is visible, it is seen to be composed of fine, compact, gelatin-like, sometimes branching, radial fibers, frequently unlike those of the superficial leaf (trabecular form) ; the latter are apt to be composed of thicker, whiter and more loosely formed strands that tend to be wavy, and to anastomose and at times form arcades.

The Vigment Seam (Excrescences) of the Pupillary Border. Seen from in front, the normal pupillary border of the iris (pupillary termination of the deeper leaf) is marked by the presence of a blackbrown seam which, when magnified, appears beaded, especially when the iris is not dilated (Plate XLI, figs, i, 2). However, only the side toward the black pupil has this appearance; the stromal edge is smoother. B)'" daylight this seam appears almost black, but with the sharply focused beam of the biomicroscope it is always dark brown in color. As the pupil dilates and the pupillary zone of the iris draws back under the frill and ciliary portion, the pigment seam loses its beaded character and becomes drawn out in the form of



Fig. 314. A. Surface markings of iris (contracted pupil), b. Appearance of surface markings of iris with pupil in mid-dilation.


a thin line (Fig. 314 B). Hence, it is always seen better in the undilated pupil (Fig. 314 A). After miosis, a previously almost invisible pigment seam may become prominent (Plate XLIV, fig. 6 ) . When examining the border with the focused beam, it is advisable to have the beam directed from the opposite side in order to see the curved edge which is directed toward the lens. With occasional exceptions, the average width of the pigmented pupillary seam varies from 0.04 to o.i mm. when the pupillary diameter is about 3.5 mm. In Negroes it is somewhat wider. In children, because the pupil is wider normally, the pigment border is narrower and is not seen as well as in adults. In a series oi 6 } children between the ages of 9 and


10 Fuchs found that when the pupil had an average size of from 4 to 6 mm., the upper pigment border is .05 rhm. in width. If the pupil is narrowed to i mm. a widening of the pigment border occurs up to o.i mm. or more.

Individually the beads or prominences (excrescences) of the seam vary in size and are curved toward the lens. They are separated one from the other by crevices which change with pupillar)'- movement. The crevices are not always equidistant from one another. At times, with higher power, it may be seen that tongues of pigment extend peripherally from the base of the excrescence to the stroma. In other cases the attachment to the stroma is smooth and sharp but generally one gets the impression that the pigment edge is slightl) rolled in. With higher power it will be seen that the surface of the excrescences, especially near the pupillary side, is not smooth but is granular owing to the deposition of small dots of pigment. Near the pigment excrescences and lying over the area occupied by the sphincter, small globes of retinal pigment may occur either singly or in groups. When large they may resemble nevi. These probably represent the clump cells of Koganei (Salzmann)


Normally, the upper part of the pigment seam is generally wider and more dense than the lower. By micrometr) Vogt observed this difference in more than 50 per cent of cases examined. Although the comparative width of the upper and lower seam is variable, in a series of cases described by Vogt the upper border measured between 0.05 and 0.06 mm., and the lower from 0.0 1 to .02 mm. in children from 6 to 16 years, while in adults it was 0.065 above and 0.03 to 0.04 mm. below. In rare instances it may be twice to three times as wide above as below. Frequently the beading effect of the pigment of the lower pupillary border is more distinct even though this border is narrower. Occasionally the pigment excrescences may be missing in this region. This has also been found in association with the so-called physiologic h5poplasia or partial coloboma of the mesoderm, commonly occurring in the inferior segment of normal blue irides (Plate XLI, fig. 4) . Considering the fact that this type of hypoplasia occurs in a normal iris and that the missing pigment is not found deposited elsewhere (e.g., on the stroma as might occur with certain anomalies or in disease) such a phenomenon cannot be considered as pathologic.


Total absence of the pigment excrescences is rare. Koby has described a case in which this was found. Before making such a diagnosis, as Mawas has pointed out, the pupil should be examined in miosis. The difference in width between the upper and lower pigment seams was first noted b^ Fuchs, who stressed the fact that this variation was not caused by any tendenc);- to entropion below and also that it may occur unilaterally. One ma}'^ be called upon to differentiate such a h^'^poplasia from an acquired defect. In the former the decrease in width is gradual and extends over a considerable area, while in the latter it tends to be sharply localized. The tendency to overdevelopment of the upper pigmented border may likewise be geneticall}'- determined - a condition whose extreme state is seen in flocculus (Plate XLIV, figs. 4, 5 ) . Some investigators have even gone so far as to consider this condition atavistic, since overdevelopment of the upper pupillary pigment border is normal in horses and ruminants.*


Infrequently, an irregularity of the pigment beading occurs in which the beading is slightl)^ angulated or dentate (Plate XLIII, fig. 4). This may be due to invisible defects in the stroma which results in less traction at these points.

TJje Sphincter Iridis. Biomicroscopically the sphincter of the normal iris can be seen only in occasional cases and then only in blue, gray, or lightly pigmented irides. Lying deep in the stroma of the posterior leaf of the pupillary zone, the visibility of the sphincter depends not only on the pigmentation but also to a greater degree on the density of the overlying trabeculae (Fig. 312). Flence in some cases only the distal edge of the sphincter can be faintly discerned, while in others its full width is apparent (Plate XLII, figs. 2, 3 ) . In the latter case it is seen as a grayish or more commonly as a yellowish feltlike band, concentric with the pigment seam.

In certain animals hypertrophy of the border pigment (flocculus) may be extreme; this is thought to be a protective defense against light coming from above.


This band measures from 0.7 to i mm. in width, varying with the size of the pupil. In structure it seems to have a uniformly solid consistency and even when highly exposed, e.g., in albinism, senile rarefication, atrophy of the iris, or in blue irides of light texture, it is impossible to make out any details or striations in its structure (Plates XLIII, figs. 4, 5; XL VI, figs, i, 2). Although frequently discernible in diffuse illumination, the sphincter is best seen by reflected light as obtained by indirect illumination. Oscillatory movements of the beam will display its high degree of mobility. Depending on the amount of dilation, the width of the sphincter ma)'- narrow by 0.2 to 0.4 mm. In maximal dilation it becomes invisible owing to the fact that the entire pupillary zone telescopes under the ciliary part of the iris.

Iris Coloration

The color of the normal iris is determined by genetic factors. The working of these factors is as yet not completely understood, though the following facts are found to be true in the majority of cases: Blue color is recessive to gray, green, and light brown, which in turn are recessive to dark brown. A person who has dark brown eyes (a color transmitted as a Mendelian dominant) has, therefore, at least one parent whose eyes are dark brown, while on the other hand a child of parents who both have dark brown eyes may be light-eyed. Since, however, the darker colors are not always fully dominant over the lighter ones, mixed colors may appear occasionally instead of pure dark or pure light colors. Then again, although blue eyes theoretically are homozygous, all the children of two blue-eyed parents should be blue-eyed. Actually this occurs in only 88 per cent of cases. Twelve per cent of the cases have brown eyes, showing that although both parents had blue eyes, at least one of them must have had a "latent” gene for brown.

Anatomically, the color of an individual iris depends on the presence or absence of stromal pigmentation (melanophores) and on the density and thickness of the stroma. Except in albinism the posterior retinal pigment layer is always dark brown in color. When


die stroma is unpigmented, its tissue is wliite or gray. By diffraction, the passage of light tlirough this tissue gives the impression of blue or gray depending on the compactness and translucency of the unpigmented stromal tissue. When the tissue is less transparent, the iris is gray. A similar phenomenon also determines the blue color of the cerulean lens opacities, in which thin whitish opalescent opacities are viewed against the background of the black pupil. The blue color of the sky can be explained in the same manner, i.e., diffraction of light occurs through the atmospheric haze against the darkness of the heavens. The presence of melanophores in the stroma gives the iris its brown color. '*â– These cells, when present, are most prevalent in the anterior border of the iris although the deeper trabeculae, when visible, will also be seen to be pigmented. Contrary to what occurs in the fundus, in the iris, owing to the thickness of the adventitia of its vessels, practically no reddish reflex results from its illumination and hence the rich vascularization of the normal iris tissue plays no role in its coloration. When the stromal pigmentation is sparse, the iris color may vary from a greenish to hazel color (Plate XLII, figs. 6, 7, 8 ) . However, when the stroma is uniformly pigmented the iris will be brown. When the stromal pigmentation is greater, the iris appears darker brown. Even in the Negro, whose iris (by low degrees of diffuse light) may appear black, actually in direct focal light it is always dark brown. This is also true for the color of the pupillary excrescences. One must always use caution in judging the exact color of tissue or cells when using the biomicroscope. Unless monochromatic light is employed, apparent differences in color will be confusing. For example, an iris that appears to have a brilliant light-blue background by daylight may have a light brown background by focal illumination (Plate XLI, figs. 7, 8). In each case the surface trabecular fibers will be whitish. In other words, with the focal beam, sufficient brownish or yellow reflection from the pigmented posterior face of a blue iris may give it a brownish or yellowish tinge.

In certain albinos the iris, although devoid of retinal pigment, may have a brownish color if stromal melanophores are present.


The varieties of normal iris coloration are so different from individual to individual as to defy any s^'^stematic description. In a sense it is difficult to separate variations in color from those of structure since the visibility of the iris architecure (trabeculae and surface markings) depends on the degree of pigmentation. In the main, two types appear: (i) light colored irides (blue or gray) having a visible fibrillary structure and (2) brown (light or dark) irides which may reveal a trabecular structure or may have a uniform smooth or spongy surface devoid of any trabecular architecture. However, in both types of irides the mesodermal layer can exist either in rudimentary form or in a state of full development. In the latter case the frill (collarette) and the superficial crypts and trabecular arcades will be present.

Ordinarily in brown irides it is impossible to discern individual melanophores. However, with high magnification in the smoothsurfaced dark brown iris (without trabecular structure) one receives the impression of a fine surface net of delicately branching starlike structures.

Isolated spots or groups of pigment spots (freckles) varying in size and shape, are commonly seen in irides of all colors and are found in all parts of the iris surface (Fig. 312; Plate XLII, fig. 6). With the slit lamp it is possible to observe the physiologic flat spots by indirect illumination, i.e., focusing the beam alongside the spot so that some of the reflected light actually retro-illuminates them. Using this type of illumination it will be seen that the spots are granular in character and are made up of irregularly sized pigment dots. Even though they appear solid to the unaided eye, it is the author’s belief that the granular aspect of physiologic iris spots differentiates them from nevi or melanomas; the latter are more solid and closer in appearance to the ectodermal pigment excrescences of the pupillary margin. Frequently some of the pigment grains outline a trabecula on which they lie. By direct focal illumination with the narrow beam one gets the impression that they lie directly on the iris surface and not within the tissue itself. Occasionally, when the spot is near the pupillary margin, it may send processes (pigmented) to the seam. But these will always show a difference in color and structure from the retinal pigment of the seam.


In blue irides multiple pigmented spots may result in the so-called "piebald iris,” in which dark brown patches distributed around the circumference of the iris stand out in bold relief (Plate XLII, fig. 7) . This type of spot is seen even in dark irides of uniform surface pigmentation; It is thought that those situated near the sphincter are formed from the clump cells of Koganei, which embryologically appear to be derived from the ectodermal pigment layer. When numerous or extensive, such areas of pigmentation, especially if more marked in one eye, can result in a picture resembling a partial physiologic heterochromia, and in the extreme state, even melanosis iridis (page 806). Whether or not it is proper to consider "nevi” as being derived from such physiologic iris spots brings up the conjectural question of the origin of pigment and the derivation of pigmented tumors. At the present time it would seem that the physiologic iris spots are formed from condensation of melanophores; if it were proved that melanophores were derived from the neuro-epithelium then it might be correct to postulate that nevi could be formed from the massing or proliferation of physiologic iris spots. But there is considerable evidence to show that mesodermal tissue has the function of melanogenesis; hence we shall consider that the physiologic iris pigment spots differ from nevi, at least in so far as their origin is concerned.


The use of the term "nevi" to describe the more tumorlike masses of pigment spots on the iris surface or in the stroma is unfortunate since they do not contain the typical nevus cells found in cutaneous nevi. In the case of the iris they are merely a concentration of the usual benign melanophores in normal iris tissue. Although cases have been reported in which these spots took on a malignant transformation (melanosarcoma), it is still doubtful whether this is actually so. Fuchs (1917)^®® believed that the pigment spots previously seen at the site of a developing malignant iris melanoma were not benign nevi but actually slow growing malignant cells. It must be admitted that, when they are very small, it is not always possible with the biomicroscope to differentiate between these "physiologic” pigment spots (nevi) and those of beginning malignancy."' However, the ordinary "nevus” found in irides of different colors are generally composed of groups of brown pigmented cells in an area of condensed normal tissue of the anterior border layer of the iris (which favors a mesodermic origin) . According to Streig (1915)'’"^ these are only transition structures or the expression of partial heterochromia. The margins of these cell groups are not sharp but merge irregularly into the neighboring stroma. Histologically the pigmented processes of these cells composing the nevus often reach into the deeper layers of the stroma (Fuchs, 1913). Similar nonpigmented structures in the iris are the grayish Wolffian bodies or nodules frequently seen at the periphery of normal irides.


One should make a differentiation between the so-called pigmented nevus and the benign melanoma. The term "melanoma” should be reserved for those structures in which a small hyperplasia of the posterior ectodermal (retinal) layers occurs. Such a benign epithelial growth may occur at the pupillary margin (as in flocculi) or over the pillar edges of a coloboma, or it may be seen protruding anteriorly through the stroma, appearing as a dark spot or mass. In the latter case the site of predilection is near the sphincter edge (region of the clump cells, Koganei) but no area of the iris is exempt. This type of growth at the pupillary margin may be solid or cystic. However, when its protruding surface is small and flat, it is usually impossible to differentiate a benign melanoma from a nevus. Not infrequently this form of proliferation so resembles a malignant growth clinically as to be indistinguishable from it. Any increase in growth of one of these melanomatous spots should be regarded with suspicion. In a case of neurofibromatosis (von Recklinghausen’s disease), Goldstein and Wexler (1930) found well-formed melanomas of the iris associated with nevi iridis. Other

Even using higher powers, one cannot discern any delicate branching processes of tlie pigment cells characteristic of melanophores. If this were possible, it might be a means of distinguishing betss'cen the harmless nevi and malignant melanomas.


authors have described small pinpoint dots of pigment; Vogt has reported ectropion of the retinal pigment.

A commonly encountered form of iris coloration known as double coloration is that in which the color of the anterior leaf (from the periphery to the collarette, i.e., the ciliary zone) differs from that of the visible deeper leaf (from the collarette to pupillary border,

i.e., the pupillary zone). One or the other of these parts in an individual iris may be pigmented or light colored, for example, the ciliary part may be brown and the pupillary part light or vice versa (Plate XLII, fig. 8 ) . This, naturally, may affect the visibility of the delicate fibrillar stromal structure in the pigmented parts, since, as previously mentioned, they can only be seen in light colored irides or the unpigmented parts of a mixed colored iris.


Simple heterochromia (heterochromia iridis) seems to be a hereditary condition characterized by a definite difference in color between the two eyes or by zones of different color in a single iris. (This is in contrast with complicated heterochromia in which the differences in color can be explained by the presence of some pathologic process.) Simple heterochromia can be total or partial (heterochromia iridum) . Several geneticists have compiled pedigrees proving the hereditary transmission of this anomaly; it is more common among animals than in man.

According to Kraupa (1923), color variations of the iris may be classified as follows:

1 . Primary - congenital or dependent on a congenital substratum.

A. I. Uncomplicated heterochromia

2. Melanosis iridis, especially with star formation

3. Double coloration in a single iris

a. Iris bicolor (blue green with yellow mesopigment)

b. Nevus iridis (partial melanosis)

c. Ectodermal pigmented deposition.

( 1 ) Clump cells

(2) Ectropion uveae "

B. Heterochromia (E. Fuchs)

11 . Secondary (neurogenic)

A. Sympathetico-heterochromia

B. Following intra-ocular disease (iritis, glaucoma, hemorrhage, siderosis)

Size and Mobility of the Pupil

Ordinarily the pupillary diameter of the normal iris varies in size from 3 to 5 mm. according to differences in illumination and with accommodation and convergence. As a rule, it is wider (i) in children than in adults, (a) in females than in males, and (3) in myopia than in hyperopia. Biomicroscopy affords the best method of observing pupillary mobility. Because of the usual oscillatory movements of the eye while being examined with the focal beam, varying amounts of light enter the pupil, resulting in almost continuous rh^'thmic dilatations and contractions. The trabeculae of the deeper leaf in the pupillary zone are intimately connected with the sphincter and instantly respond to its movements. As the pupil dilates, these fibers become shorter by wrinkling and similarly lengthen and straighten out during contraction. In a passive way the fibers of the superficial leaf indolently follow these movements.

When the fibers of the pupillary zone run in an eccentric direction toward the pigment margin, frequently crossing others, action of the sphincter results in a scissorlike movement of these fibers. In the early stage of mydriasis, as the pupil begins to widen, the pigment excrescences of the seam begin to stretch out and to lose their beaded character. Eventually, the seam is drawn out into a thin fine line and with maximal dilatation may be hardly visible (Fig. 314 A, B). At the same time the pupillary zone slides under the frill and superficial leaf. Before the pupillary zone disappears, the cleft of Fuchs becomes exaggerated ; finally the frill itself seems to form the pupillary margin. As dilatation continues, the remainder of the visible iris (now including the invisible telescoped pupillary zone) contracts itself as a unit. The contraction furrows deepen in a way similar to the action of an accordion, thus accommodating to the thickening of the tissue, which must fold in order to occupy a smaller area. As mydriasis wears off, the same phenomenon occurs in reverse. The contraction furrows flatten out; then the pupillary portion becomes visible, sliding axially from under the ciliary part. As the pupil becomes smaller, the seam widens and the crenations or headings are more marked. In miosis the puckering of this pigment border (which is firmly connected to the axial edge of the sphincter) may actually appear as if it were somewhat everted (physiologic ectropion) under the purse-string action of the sphincter. When this occurs, the optic section will reveal a fortuitous widening of the space between the iris pigment border and the anterior lens capsule, enhancing the communication between the anterior and posterior chambers. It is interesting to observe the action of the trabeculae during contraction and dilation of the pupil. This can only be seen in lightly colored irides where the movements of the individual fibers can be followed. The greatest action is seen in the pupillary zone and in the region of the lesser circle. The amount of visible movement varies inversely as the ciliary region is approached. When the pupil contracts, the angles formed between the crossing and branching trabeculae narrow (the movement reminding one of the opening and closing of innumerable pairs of scissors) while during dilation these angles widen.


The pupillary opening is not situated in the exact center of the iris diaphragm; but a little to the nasal side and below the center. According to Koeppe, this results in a slight rarefaction of the trabecular system in the middle temporal sector and is apparent in the light colored irides of the young. This physiologic decentration of the pupil probably is related to the embryologic closure of the fetal cleft. The temporal rarefaction together with the similar defect in the lower part of light blue irides, previously mentioned, does not affect the circular shape of the pupil. It is still unknown whether or not the iris trabeculae are elastic or whether they exert any traction effect in the mechanism of pupillary motility. The normal circular shape of the pupil may rather depend on the oblique connections between the sphincter and the dilator (page 733). These connections may serve to flatten and extend the sphincter. However, it must be understood that pathologic variations in stroma can affect the shape of the pupil, in addition to other causes.


The Senile Iris

As part of the aging phenomena the iris undergoes progressive changes. There is no doubt that the tendency of tissues to show the signs of senescence varies with the individual. In some persons, progressive changes such as arcus lipoides, iris atrophy, cataracts, vitreous degeneration, and graying of the hair, appear relatively early (pr.esenile changes), probably induced by hereditary determinants, similar to the abiotrophies. The factor of nutrition must also be kept in mind. In others, these changes may occur either in great age or not at all. There is certainly no uniformity in their appearance as indicated by their selective presence in one tissue and absence in another. It should be remembered that changes identical with those of senility can occur in the young after disease. The type of change visible by means of biomicroscopy naturally depends on the morphology, state of differentiation, and function of the tissue. The lesion may be infiltrative or destructive. An example of the former occurring in the cornea is arcus senilis; depigmentation in the iris is a manifestation of the latter. The symmetrical aspects not only of normal features, such as the design of the pupillary pigment excrescences or details of iris color, but also the exact similarity in appearance of such changes, as senile atrophy of the pigment border, pingueculae, and cataracts in uniovular twins, as reported by Vogt, strongly indicates that so-called senile changes are genetically determined. On the other hand, it is possible that outside or accidental influences may modify, retard, or hasten the appearance of such changes. As Duke-Elder so aptly puts it "the processes of senescence should rather be calculated in terms of intensity of living, of heredity, and of the cumulative effects of rude shocks or quietly progressive toxemias.”

Biomicroscopy affords us an excellent means of observing the "aging” processes in the iris which may involve all or any part of its mesodermally or ectodermally derived tissue. In a general way senile changes in the iris resulting in atrophy of the stroma, degeneration, and depigmentation of ectodermal pigmented epithelium and the tendency of dispersal or even proliferation of pigment may be classified according to the parts chiefly affected as: (i) changes of the pupillary pigment border (seam) ; (2) circummarginal border changes adjacent to the seam; (3) rarefactions of stroma and posterior retinal pigment layers distant to the pupillary margin.


Seuile Changes of the Pupillary Pigment Border. The principal and most typical senile change in the iris pigment seam is one in which destruction and migration of pigment occurs (Plate XLIII, fig. i).


Because the pupil tends to become smaller with age and with adjacent stromal changes, it is not uncommon to see an increase in prominence of the pigment excrescences of the pupil border during middle life and even occasionally in the aged. As a rule, however, with the passage of time, owing to disintegration and dispersal of pigment a segmentation of the seam occurs which is followed by a progressive decrease in the number of excrescences so that in certain areas they may completely disappear. Such changes may be minimal or may progress until the seam is completely destroyed. The pigment itself, being free, may be transported by the aid of the aqueous and gravity and be deposited on the posterior corneal surface, the anterior lens capsule, the surface of the iris, in the chamber angle, and even on the remaining pupillary excrescences, forming nodes. The deposition of pigment particles on the excrescences may cause them to have a dentate appearance. Pigment may migrate superficially within the stroma itself or may be deposited on the surface among the trabeculae in various guises, e.g., spheres, clumps, or particles (Plates XLIII, fig. 2; XLIV, fig. 3). An apparent disappearance of the pigment seam, simulating senile destruction, may occur with posterior synechiae following iritis. If the adhesion of the iris pigment border to the anterior lens capsule occurred while the pupil was partially dilated, it might become inverted or rolled in when the iris regains its mobility and the pupil becomes smaller. However, dilatation with a mydriatic would reveal the presence of the seam at the point of attachment to the capsule. Such an inversion of the pupillary border may include part of the sphincter at the site of the synechia and cause the sphincter to be narrowed or absent. But,


Fig. 315. Senile .ntropliy of pupilinry border .and stroma as seen by retro-illumination. Note lacunae resulting from loss of substance; also migratory secondary pigmentation.

Fig. 316. Senile circummarginal sulcus. (After Vogt.)


again, dilatation of the pupil reveals the actual condition (posterior synechiae) and the sphincter edge reappears or widens.

Senile atrophy may result in a rarefaction of the pupillary margin which is easily seen by means of retro-illumination (Fig. 315). To demonstrate the atrophic nasal iris border by this method the light beam is diverted from the temporal side into the pupil so that it passes obliquely into the lens in the vicinity of the nasal border. Conversely, to examine the temporal side of the iris the process is reversed so that the beam is directed temporally from the nasal side. If the pupillary marginal pigment is intact no retro-illumination occurs. However, if rarefaction of the retinal pigment has occurred the border may appear moth-eaten or delicate translucent pearlygray or blue areas may be seen like empty filmy envelopes. The normal contour of the pupillary margin is retained, appearing in the


later stages of this process as a whitish veil somewhat glassy in texture.

Occasionally, a senile hypertrophy of the pupillary pigment seam may be seen instead of atroph)'- (Plate XLIII, fig. 4). This change, which is more likely to occur above than below, is characterized by a sharp angulation between the enlarged individual pigmentary excrescences. Such a condition may not be due entirely to an overgrowth but rather to a slight eversion as occurs in miosis (since the pupillary diameter is alwaj'^s narrower in senility) augmented by traction exerted by sclerosed stromal fibers which are unable to stretch or elongate sufficiently as the pupil gets smaller.

Senile Chcummarginal Changes (Adjacent to Seam). Gutter formation (sulcus circummarginalis of Vogt), atrophy and destruction of the stroma and posterior retinal pigment layer can occur, immediately^ adjacent to the pupillary seam (Plate XLII, fig. 2). The area involved is rarely more than from o. i to o. 5 mm. in width (Vogt) and is best seen in light-colored irides. At times a narrow, glassy-looking furrow, partly or completely encircling the pupillary border, may be seen (Fig. 316). The walls and floor of this gutter have a homogeneous character. It is usually impossible to see any of the normal radiating stromal trabeculae within it. In some cases it seems as if the radiating fibers stop at its distal edge. In blue irides this furrow appears yellowish in color and in brown irides it is less pigmented than the surrounding stroma. The pigment excrescences may be missing or only slightly attenuated. Frequently, I have seen such circummarginal changes without any depression or gutter. This may represent an interim stage of sulcus circummarginalis.

Concentric with the seam, there may be a narrow area of stromal atrophy through which the deeper and darker retinal pigment layer may be seen. Occasionally, a few strands of stromal fibers may traverse this atrophic area to the pupillary pigment seam. Senile atrophy and destruction of the pigment border and the adjacent posterior pigment layer may result in a marked rarefaction; this occurs in the form of irregular areas or triangular (cuneiform) sectors, the apices of which are directed toward the periphery, or in the form of clefts, apjjearing almost as if caused by a lateral separation of the excrescences (Pig. 315). Such areas of destruction may be confined to isolated portions or may extend circumferentially around the border in a continuous or segmented manner. In some cases these marginal defects may extend peripherally in the posterior retinal layers as far as the region of the contraction furrows, and they may leave depigmented translucent areas in the form of radial streaks or Irregular perforations which can be outlined by retroillumination. The seam is usually missing in these areas and a fine dispersal of the pigment may occur in the neighboring stroma. The finding of such pigment dispersal in the stroma (particularly in blue irldes) as a senile change tends to refute the idea of Koeppe that by itself it represents a preglaucomatous change. In ordinary direct illumination or daylight, as a result of reflection from residual uncolored stroma, it may seem that except for an absence of excrescences the border is normal. However, retro-illumination, especially if aided by a cataractous lens, discloses that the iris margin of the alTccted areas consists of nothing more than a diaphanous veil, devoid of retinal pigment and with only a film of stroma remaining. By daylight or ordinary oblique illumination the iris border may appear somewhat whitish and hence before the days of biomicroscopy (retro-illumination of the iris border by lens light), it was incorrectly interpreted as being due to a "hyalinlzation” of the pupillary margin. This type of atrophy of the pupillary margin is similar to that which occurs after chronic iritis and especially in heterochromia iridis.

Sctiilc Karejaefion of the Sfrowa and Layer of Refjnal Figment Distant to the Pupillary Margin. With age, especially in those lightly pigmented cases in which the stroma trabeculae can be seen, one

It is extremely doubtful wlietlier tlie so-called hyaline degeneration of the pupillary margin of Fuchs (1884)'’’” can be seen biomicroscopically. Pathologically, it consists of a hyalinization of the stroma and adventitia of the vessels, especially behind the sphincter and is supposed to result in senile miosis and rigidity of the pupil. In all simple senile cases which I examined, in which there was a whitish band at the pupillary margin, retroillumination revealed destruction of the pigment seam with the resulting diaphanous veil. In several cases the whitish tissue consisted of flakes of exfoliated lens capsule (seam intact), though in two of these (with normal pressure) no areas of exfoliation could be seen in the central exposed parts of the anterior lens capsule.


776


BIOMICROSCOPY OF THE EYE


becomes aware of definite thinning of its entire structure, although the individual trabecula may become more fibrous and less transparent, resulting in a loss of brilliance of the entire iris surface. For example, a blue iris tends to become duller and more gray in the aged.

Occasionally in light blue irides of the aged one can see a dark band between the distal edge of the sphincter and the frill, anywhere up to 0.5 mm. in width. This is probably caused by atrophy of the stroma which permits the dark unaffected posterior layers to shine through.

Another frequent t5'^pe of senile atrophy or degeneration of the mesodermal tissue, also seen in blue irides, is a form in which there is rarefaction of the deep stroma, immediately over the sphincter itself (Plate XLIII, fig. 3 ) . This causes the sphincter area to appear brownish in color. This brown area may be crossed by a few residual fibers, extending from the frill to the seam, but in any case these fibers are not sufiicient in number to prevent the deep brown color of the posterior layers from coming through.

In extreme age, especially in blue or gray irides and when the pupil is small, one gets the impression that the radiating trabeculae are less wavy and more attenuated and that the supporting tissue is more opaque and collagenous. This form of senile "sclerosis” causes a flattening of the iris surface with a tendency toward obliteration of the surface markings and crypts. At times this condensation of the iris stroma results in a loss of demarcation between the pupillary and ciliary zones (lesser circle) , the sharp slope of the pupillary zone toward the pupil no longer being noticeable. The irregular (zigzag) line of the frill itself may become so attenuated into the hyaline stroma that it is seen with diflSculty. However, this type of sclerosis (in light colored irides) never obscures the sphincter but rather makes it more visible owing to the thinness of the overlying stroma. Such atrophic changes may involve the entire iris uniformly and may cause a change in its color depending on the amount of pigment destruction. An increase, however, of stromal atrophy in localized areas may develop to the point where the posterior pigment layers


THE IRIS


777


arc exposed to view. At times only a few atrophic trabeculae may be found crossing the exposed pigment layers. Rarely, their curled detached ends may float freely in the chamber, giving the impression of a localized detachment of the stromal fibers.


Tig. 317. Senile r.uef.ictinn of posterior pigment layer as viewed by retro-illumination. The cataractou.s lens acts as a strong reflecting surface.


The more extensive senile tears or separations, especially of the superficial stromal leaf, have been described by Schmitt, Mile. Drapkin, Sander, Dollfus,’’”” and Vogt. Such separations indicate the morphologic and genetic independence of the superficial stromal leaf and remind one of other more or less spontaneous detachments or separations, e.g., of the lens, retina, vitreous, all surrounded by fluid having a lower specific gravity.'’’

Vogt has pointed out that occasionally in the pupillary area or even more so peripherally, especially in the crypts, small black points may be seen, particularly in poorly pigmented irides. These small black points represent rarefied areas in the posterior pigment layers.

Vogt believes th.it there is a hereditary disposition to atrophy or cyst formation and that gravity together with "eye movements” as a r/s a tergo are sufficient to cause these progressive separations. He has divided these separations of the iris stroma into two types: first, in which a separation of the superficial layer of stroma occurs, and second, in which there is a separation of the entire stroma (superficial and deep). When the separation is marked the stromal fibers may be seen floating freely in the anterior chamber. Some may even be in contact with the posterior corneal surface. Separation of the mesodermal layers almost always exposes the dark brown posterior pigment layers to view.


778


BIOMICROSCOPY OF THE EYE


Larger areas of rarefaction of the posterior pigmented iris layers may be seen with retro-illumination in the form of round holes, radial streaks, or as an irregular circumferential band in the extreme iris periphery near the limbus.*’' This retroreflected light, passing through unobstructed, outlines these defects, causing them to stand out lighter in color than the darker adjacent unaffected areas (Fig. 317). Atrophic areas in general are better seen when the lens is cataractous because the opaque lens reflects more light than a normal one (Fig. 317). The frequency of iris atrophy, associated with ordinary senile opacifications of the lens, comparable in a way to the findings in the syndrome of heterochromic iridis (Fuchs), is well known.

Senile Alterations of the Iris Sphincter. Changes of the iris sphincter due to age are best seen in blue or gray irides, especially when associated with rarefaction of the stroma. The sphincter appears to have an increased density which often can be seen as well by direct focal illumination as by indirect illumination. Depending on the nature of the surrounding tissue its color varies from a dirty gra)’’ to yellow or even pinkish. Frequently the sphincter appears to be narrower in age.f This may be sectorial or circumferential. Koby states that "in marked cases, it gives the impression that the sphincter has shrunk away from the peripheral part of its bed, which then becomes visible as a darker ring.” Local narrowing of the sphincter, its width being reduced to half, may occur in the region of an extensive posterior synechia following long-standing iridocyclitis. Occasionally in a blue or gray iris of the aged a dirty gray cleft separates the pigment border from the sphincter, resulting in a sphincter-free annular zone somewhat similar to that observed in circummarginal destruction of the pigment border. Vogt has described senile atrophy of the stroma in a case of compensated glaucoma in which there were narrow stripes of pigment within the sphincter.

It is not surprising that the periphery of the iris manifests rarefaction since the posterior pigment layer is thinnest there.

t On the other hand, in buphthalmos widening of the sphincter up to 2 mm. has been noted.


Cha[)icY Ninc/ccii


CONGENITAL ANOMALIES OF THE IRIS


T he fact that cmbryologically there is considerable difference in time of appearance and development of the mesodermal and ectodermal iris layers has resulted in many conflicting explanations concerning the evolution of iris anomalies.

In discussing developmental defects of the iris, Ida Mann states that "with regard to the interaction of the mesodermal and ectodermal portions of the iris in normal development not much is known. It is generally accepted that the mesodermal portion, being formed first, acts as a sort of scaffold or directional tissue plane for the subsequent forward growth of the pigment epithelium which lines it later. On the other hand the optic outgrowth can be experimentally isolated in vitro and will invaginate and form a retina and iris (ectodermal only and not usually completely formed) without contact with mesoderm at all. It is probable that both tissues are selfdetermining though the possibility of chemical interaction between them must be admitted.”

Recently, in a family of 8 it was found that 4 members had some form of persistent pupillary membrane. Many writers in this field have held that hereditary transmission of these defects is direct. On the other hand, considering the existing evidence one cannot entirely deny the influence of such factors as intrauterine inflammation; various mechanical factors and metabolic interferences (chemical, toxic, nutritional,t or glandular dyscrasias) . The importance of the endocrine secretions in the production of many types of anomalies

The ectodermal (posterior layer) projection occurs at about the 65 mm. stage, at a time wlien the mesodermal framework is well determined.

t Warkany, (Vitamins and Hormones, Vol. Ill, 1945), produced congenital defects of the eye by means of nutritional deficiencies in the mother.

779


PLATE XLIV


Fig. I. Hypertroph) of the pigment seam of the pupillary border.

Fig. 2. Double seam.

Fig. 3 . Particle of detached pigment of the seam resting on the iris surface. Fig. 4. Tuberous flocculus.

Fig. 5. Pendulous and exfoliative flocculus.

Fig. 6 . Pilocarpine cyst of the pupillary pigment.

Fig. 7. Cystic degeneration of the seam in diabetes.


780



CONGI-NITAL ANOMALIES OF THE IRIS 783

Is unccnain, considering the fact that many of these glands do not actively function until after the development of a specific type of tissue has occurred. With regard to the influence of aberrant bands or persistent vessels (persistent capsulopupillary vessel), there is clinical evidence that in occasional cases a causal relationship is indicated by their presence.

Because it is not al\va)'s possible from clinical appearances alone to explain which of these factors arc responsible for the production of the difiereni anomalies of the iris, one can only formulate a classification of these defects on the basis of extent of involvement of, or selectivity of the afiection for, one or both germinal layers. Such a classification must inevitably be faulty because it does not take into consideration possible relationship between incompletely developed ("fornia: /r/cs/c”) and completely developed forms. For example, if iris defects are divided into two groups, (i) those involving its whole thickness and (2) those involving one type of tissue predominantly (Mann), it would follow that an incomplete coloboma (defect of the mesoderm only) could not be placed under the same heading as a complete one (localized absence of both layers) even though the same ctiologic factors were at work in both cases. Consequently in descriptions of these anomalies a strict classification will not be adhered to, and only those defects that are common or interesting from a biomicroscopic viewpoint will be dealt with.'’' Since the advent of biomicroscopy many minute "subclinical” anomalies of the iris have been brought to our attention.

Anomalies of the Pupillary Pigment Border (Seam)

Because the seam is so commonly less well developed inferiorly than superiorly, such an inequalit)'^ may well be considered as falling within normal limits. The same holds true for the occasional absence of an individual pigment excrescence at the lower border. However, a majority of the malformations of the pigment border are due to localized hypoplasias of the retinal pigment layer.

^ For tliosc desiring a more exhaustive handling of these anomalies I suggest perusal of special treatises on tin's subject, and especially recommend to English readers Ida Mann s "Developmental Anomalies of the Eye."'’"'’


784


BIOMICROSCOPy OF THE EYE


Congenital redjcpUcation {doubling) of pigment border is an anomaly which according to Vogt consists of a doubling of the pigment border, is not rare and may be hereditary (Plate XLIV, fig. 2) . An interrupted circular furrow seems to divide the seam into an axial and peripheral part. The width of the reduplicated seam is usually not more than 0.1 to 0.2 mm. Reduplication of the seam may be complete or incomplete. In the former, it extends circumferentially around the border, while in the latter it may be localized to a sector as short as i mm. in length. This anomaly is probably due to an extension of the folds of the retinal pigment layer which, on reaching the pupillary border, evert and become visible as an extra seam.

Flocculus iridis is characterized by a hyperplasia of the retinal pigment at the pupillary border, appearing as nodular "grapelike” clusters or as if the hypertrophied seam were twisted on itself like a hempen rope, or as flattened and twisted elongated pendulous processes (Plate XLIV, hg. 4, 5). It is generally conceded that flocculus formation is definitely hereditary (but not sex-linked) in character. This condition must be differentiated from ectropion of the retinal pigment in which the everted retinal layers extend over and lie flatly attached to the mesodermal iris layers. Although in both these anomalies (similar to the normal seam) pigment excrescences appear black in daylight, the focal beam reveals them as dark brown in color. The fact that in man flocculi are generally situated above has caused them to be likened to the pigment processes normally hanging over the pupils of horses and cattle and to be considered atavistic vestiges. However, anatomically, flocculi in man do not have the core or substratum of connective tissue found in animals; Fuchs has shown that they consist merely of a hyperplasia of the pigment epithelium with no enclosed connective tissue. However, the tuberous type in man may have connective tissue strands (iris stromal fibers) connected to them. Ida Mann has suggested that this may represent a similarity to flocculi seen in animals, in which these structures become invaded and supported by mesoderm. It is possible that the form examined histologically by Fuchs was not of the tuberous variety.


CONGKNITAL ANOMALIES OF THE IRIS


785


Based on clinical appearances, Vogt and others consider that there arc two distinct types of flocculus iridis; both may be found together: (i) Tuberous (jlornili /iihcrosi) and (2) exfoliative and pendulous (florciili cxjolialint d Iwtidnlanfcs) . The first type, com


I'k;. 31.S. TuIktous flocculi at upper honler of the pupil.


posed of irregular humplike or globular pigment masses, usually has attached (mesodermal) stromal fibers (Fig. 318). Frequently one sees fine nets of trabecular iris tissue over the flocculi which extend peripherally to the frill. In others the frill may be absent or may be drawn up over and attached to the convoluted pigmented mass. In all cases, it should be remembered that the condition, although involving the scam, actually develops from the posterior retinal iris layer. It may be, as suggested by Vogt, that owing to an abnormally strong fixation between the frill and the retinal iris layer in the fetus, the deeper stroma fails to extend axially to a sufficient degree, causing traction with subsequent eversion and overdevelopment of the underlying pigment layer. Koby states that this form "owes its origin to a nipping off of a mass of pigment by fibi*ous processes of the mesoderm.”

The second or exfoliative and pendulous type is free of stromal attachments, and the flocculi appear as "flattened convoluted lamellae” of smooth surface or, owing to cystic degeneration, they form large globules resembling grape seeds. Several of these dark


786


BIOMICROSCOPY OF THE EYE

brown rounded globes may fill the pupil. Some may be attached to the seam and others may take origin from the posterior surface of the iris. Although both forms may remain stationary throughout life, cystic degeneration in the second form may ensue with enlargement,


Fig. 319. Pendulous form of exfloliative flocculi. (After Vogt.)


possibly leading to the pendulous kind, since frequently both (exfoliative and pendulous) are seen in the same iris.

A variant of the exfoliative type is the extreme pendulous form in which the masses may be extended in the shape of Indian clubs (Fig. 319). These elongated processes resemble the flocculi seen in animals. Unlike the tuberous variety, they are almost always found superiorly. There they are not derived from the pigment seam (which may be normal at the place where the process is attached) but rather from the posterior retinal layer behind and above it, thus hanging suspended between the lens and iris. Cases have been reported in which pendulous flocculi were held suspended by a necklike attenuated thread. This may possibly be a transition stage in their development, ending by detachment of the head, which in turn may be found in the chamber angle as a solid pigment globule or more often


CONGENITAL ANOMALIES OF THE IRIS


787


lying loosely adherent to the surface of the iris. In a few cases they have been seen floating freely in the anterior chambers. It is not unlikely that a portion of a flocculus itself may break off directly without transitional elongation. In one instance it was noticed that such a corpus mobili disappeared from view (broken down and eliminated ?). However, globules of pigment of similar appearance, lying on the iris stroma, have been seen in the absence of any flocculi formations. These detached pigment bodies may assume shapes other than spherical, appearing, for instance, flattened or bean-shaped, and though they are generally of a solid consistency, cystic degeneration may cause them to be translucent. It has also been suggested that cystic flocculi (free or attached) may be associated with a persistence of the marginal sinus. t

Vilocarp'nic Cysis of ihc Pf^incnf Border. The prolonged miotic action of pilocarpine or eserine (physostigmine) may result in the formation of cysts of the retinal pigment layer (Vogt). These are seen as pigmented globules at the pupillary border of the iris. At times these structures resemble small pouchlike bags of pigment suspended from the puckered pigmented excrescences (Plate XLIV, fig. 6). These cysts may arise from the posterior surface of the iris just behind the pupillary seam so that their attachments are hidden, or they may arise from the excrescences themselves. In the former case the pigment excrescences may be normal, and the cyst may displace the iris border away from the lens. At the base or place of attachment small furrows may be distinguished but the balloonedout portion is generally smooth. In some, the surface is smoothly pigmented, while in others it appears granular as if dusted with pigment. In some cases only a single cyst may be found, while in others the entire circumference of the pupillary margin may be dotted with them.

^ Gises have been reported in which these bodies were attached to remnants of the pupillary membrane and consequently were considered as being derived from mesodermal tissue. But it is also possible that a det.ached ectodermally-derived pigment globule may have become adherent to a pupillary membrane. Histologic evidence in almost every case has shown that these bodies arc composed of cells resembling the posterior retinal epithelium of the iris.

t The marginal sinus is a circular space between the two layers of the rim of the optic cup. It remains open until the end of fetal life, ultimately closing by fusion of its walls.


788


BIOMICROSCOPY OF THE EYE


It is interesting to note that this type of cyst is invariably related to pilocarpine or eserine miosis and is not found in untreated cases of glaucoma. The discontinuance of the use of these drugs may cause them to disappear. At times the cysts may vanish through bursting and in some instances they reform later. A shrunken or burst cyst may resemble a flocculus. As a rule, they can be differentiated from flocculi by the fact that cysts are distended by fluid and can be transilluminated if they are not too densely pigmented. Also, cysts are attached by a narrow contracted base and have ballooned-out bodies. Especially important is the fact that these cysts may be transient. The tendency of the retinal pigment to form cysts suggests that this tissue may have a secretory activity. This activity may account for the formation of the larger congenital cysts associated with the pigment (neural) epithelium on the posterior surface of the iris. The latter may be due to a persistence of the annular sinus or to the migration of clumps of retinal epithelium into the mesodermal stroma with secondary cystic degeneration.

Diabetic Changes in the Pigment Excrescences. Histologically, it has been known for a long time that swelling, cystic degeneration, and detachment of the pigment-bearing epithelium of the posterior iris surface and of the pupillary excrescences may occur in diabetes (Fig. 320). Likewise, when performing an iridectomy in diabetic patients it has been noted that manipulations of the iris may cause a bursting of these cells with the resultant formation of a black or dark brown cloudiness in the anterior chamber owing to dispersal of the pigment."' With the biomicroscope, evidence of such edematous or degenerative changes in the retinal iris pigment will often but not invariably be seen in diabetic patients. When the pigment excrescences of the pupillary border are so affected they are enlarged and have a spongelike or porous aspect, appearing pitted (Plate XLIV, fig. 7). This rarefaction can frequently be demonstrated by

The sudden appearance of a dark cloud (evidently fucsin) in the aqueous during mydriasis in cases of senile exfoliation of the anterior lens capsule has been seen by Vogt in nondiabetics. These cases were complicated by glaucoma, and the patients had been subjected to prolonged miosis. In these instances the cloud might result from the bursting of (pilocarpine) pigment cysts, although in a case of untreated chronic simple glaucoma a similar occurrence took place.


CONGI-NITAL ANOMALII-S OF THE IRIS


789


rctro-illuminailon, in wliich case tlic pigmented border may appear to have a lacy texture. At the site of a posterior synechia the attached porous excrescences may be drawn out into dentate pyramidal processes. In some instances the pigment border itself may be unaflected but reiro-illumination may reveal atrophy of the posterior pigment lining in the form of radial or irregular lacunae distal to the pupillary margin; these lacunae resemble senile or post inflammatory atrophy of the iris. As a rule little change is noted in the stroma but free pigment granules may be scattered over its surface.


1 !

Fig. 320. Histolo^jic prcp.ir.ition of q'.stic de/;cncr.ition (glycogen infiltration) of the pigmentbearing epithelium of tlie posterior iris surface (diabetes). (After Gilbert.)

Eefropion (Hyperplasia) of the Retinal Pigmented Layer of the Iris."' Although not uncommon in pathologic states of the iris, e.g., absolute glaucoma (page 868), ectropion of the retinal pigment layer rarely occurs as a congenital malformation, in many instances being of proved hereditary origin. The presence of this anomaly in identical twins (Vogt) seems to indicate beyond controversy that this is true. However, it is pi'obable that fetal inflammation may

The older appellation, congenital ectropion of the uvea, should be discarded since the everted pigment is ectodermal in origin.


PLATE XLV- Fig. I. Congenital ectropion of the pupillary border with distortion of the pupillary outline.

Fig. 2. Ectropion of the pigment of the pupillary border of the iris.

Fig. 3. Ectropion of the pigment border of the iris (apron form) with area of melanosis iridis.

Fig. 4. Partial coloboma with pigment stars on the anterior lens capsule.

Fig. 5. Aniridia. Observe the 2onular fibers and the unusual type of lamella cataract. Right eye.

Fig. 6. Same case as shown in Figure 5. Left eye.

Due to editorial changes this plate was originally Plate V (see opposite page).


790


CONGENITAL ANOMALIES OF THE IRIS


793


be a causal factor in isolated "congenital” cases. Ectropion of the retinal pigmented layer of the iris is similar to flocculus in that there is an extension of the border pigment; it differs from flocculus in the fact that in ectropion the pigment never hangs free in the anterior chamber but lies flatly attached to the iris stroma. Moreover, ectropion has no predilection for the upper pupillary border but may occur anywhere on the iris.

Two forms of this anomaly may be seen: (i) ring form in which tlie pigment eversion (generally narrow in width) extends completely around the pupil; and (2) apron form in which a partial sectorial overlapping of the stroma occurs. On hasty examination students have been seen to mistake the first for an enlarged pupil and the second (when large) for a coloboma (pseudocoloboma) or even an irregular pupil (iritis) . Such errors naturally would occur only when a superficial examination was made b)’- daylight and would be impossible with biomicroscopic inspection.

The degree of ectropion varies from case to case (Plate XLV, fig. I, 2, 3). In some, all that is seen is a small eversion from 2 to 3 mm. in extent, at any point of the marginal circumference. Such small eversions may not reach the frill and their surface is pigmented corresponding to the serrations of the seam. As a rule, the eversion seldom extends beyond the frill (although cases have been noted in which the pigment has extended over the sector of the iris as far as the peripher)) • The smaller ones, 0.5 to i mm., may disappear during mydriasis. The surface of the ectropion is usually smooth in the area away from the rounded and slightly dentate pupillary margin, though on occasion radiating serrations may extend peripherally for a considerable distance (Fig. 32i),'-' All these serrations or folds tend to flatten out with mydriasis. At times I have noted small lumplike pigmented surface nodules in distal parts. The fact that there is alwa^'^s perfect action of the pupil in the involved area seems to indicate that the sphincter is not involved in this condition. Occasionally one will notice a small thickened area of hyalinization of the

^ Pathologic ectropion is characterized by little or no striations at the pupillary margin, as well as by enlargement of pupil and extensive stromal changes.


794


BIOMICROSCOPY OF THE EYE


iris stroma near the distal apex of a slight ectropion, just in front of the frill, resembling a scar. In some only a few pigment granules may be seen in the stroma scattered in the vicinity of the eversion;


Fig. 321. Ectropion of retinal pigment showing radial serrations at the pupillary margin.

in others a considerable area of lighter brown pigmentation is found surrounding the ectropion.

The exact mechanism involved in the production of this anomaly is imperfectly understood. Normally the double layer of pigmented epithelium follows the mesodermal scaffolding until it reaches the pupillary margin and forms the pigmented seam as seen from in front. It is conceivable that if the growth of stroma in the pupillary area is retarded, the extension of the posterior pigment layer can advance a little ahead of it and can extend around the anterior surface until it meets the delayed superficial stromal growth. Moreover, it has occurred to me that if the terminal end of the retinal pigment layer (marginal sinus) became attached to the back of the embryonic pupillary membrane, it might be drawn back by traction when atrophy and retraction of this membrane occur during further development. An adhesion of this type in association with a cystic


CONCJI-NITAL ANOMALIES OF THE IRIS


795


detachment of the marginal sinus might also be a factor in the production of flocculus.

Principally Involving the Stroma

i\Uni>n<jl Defer/s of /he S/ronm. Minute defects of the stroma are seen occasionally. They may be localized or appear in several areas. One example of the latter is found in cases in which fine stromal trabeculae extend over the pigment border in the form of hooked strands very much like clasps. Still another is that in which the frill (lesser circle) is in contact with the seam itself (Plate XLI, fig. 9). Anterior adhesions of the iris stroma to the posterior corneal surface may occur in the periphery, or extensions of the frill may be attached to the pupillary area of the posterior corneal surface."’' Vogt has described small nodes of condensed tissue lying on the iris surface at times associated with a gap in the seam and ectropion. Other local condensations resemble scars and exert traction on the frill (Plate LVI, fig. 2). In these defects the surface tissue appears clouded so that the radial strands are indistinct. Occasionally a vessel may be present. In another case described by Vogt there was a small atrophic area of stroma with exposure of the posterior pigment layer. At this point there was an absence of the sphincter tissue, indicated by a lack of pupillary action. The rarefaction was in the horizontal meridian so that it bore no relation to the fetal cleft. Such local mesodermal thickenings or atrophies suggest inflammatory lesions during fetal life (fetal iritis).

Occasionally in blue irides an increase in stromal pigmentation in the region of the frill may be observed. This tends in rare cases, according to Vogt, to form a light yellow or orange colored ring regularly concentric with the pupillary margin. In other instances, more common than the above, a heavy, irregular or spotty brownish pigmentation may occur in the superficial leaf of a blue iris near the frill. These pigmented or melanomatous spots resemble pigmented nevi. When such spots are found in the pupillary zone (deep stroma) they may be derived from the clump cells of Koganei, normally seen See Volume I, Plate XXXVIII, fig. 3


796


BIOMICROSCOPY OF THE EYE


in histologic preparations near the sphincter. It is not unusual to see darkened clumps of pigmented cells in the superficial stroma of brown irides, but when such spots are scattered over a light colored iris (blue or gray), the iris has a greenish hue (piebald iris).

Physiologic Rarefaction of Stroma. If one studies the deep blue irides in daylight, a dark sector or shallow groove will frequently be seen in the ciliary zone directl}'- at 6 o’clock (Plate XLI, figs. 3, 4). This is caused by a hypoplasia of the stroma in the region of the fetal cleft and may be considered as a physiologic fetal rest or possibly as a rudimentary coloboma. In Italians, Streifi found it in 25 per cent of normal irides examined. This defect is best noticed macroscopically by diffuse illumination or even better by daylight, and ma)^ appear as a large crypt or as a sector of rarefied stroma which permits the deeper retinal layers to show through. In the region of the defect the frill and contraction furrows may be absent. In one case examined b)^ the author there were no pigment excrescences at the pupillary margin of the affected part. The close relation between ph^'^siologic rarefaction and incomplete colobomas is well illustrated in a case reported by Mann. In this case there was a physiologic rarefaction of the stroma below in one eye, while in the other a similarly situated rarefaction was accompanied by a small notch of the pupillary margin. In addition, retro-illumination produced transillumination of the involved segment, indicating partial absence of the retinal pigment layer.

Coloboma Iridis. Coloboma iridis is a common developmental anomal} of the iris and is usuall) hereditary, although it may occasionally result from other causes. In contrast to aniridia (page 799) in which there is an almost complete absence of the iris, the term "coloboma” signifies the absence of one or more sectors of the iris. The literature describing iris coloboma is replete with classifica

This type of physiologic rarefaction of the stroma, however, differs from a Fuchs’ crypt. Fuchs’ crj'pts are found in any meridian of the iris surface, and only involve the superficial stromal leaf. Also their margins are sharply outlined by the trabeculae of the superficial leaf and they rarely extend to the ciliary iris margin. Physiologic rarefaction, on the other hand, only occurs below in the region of the cleft, extends from the seam to the ciliary margin, and involves the stromal thickness, its boundaries subtly merging with the unaffected neighboring iris tissue.


CONGENITAL ANOMALIES OF THE IRIS


797


lions and subdivisions depending on the location, size, or tissues involved. For instance, a coioboma is regarded as being typical when it is located below in the direction of the fetal fissure or cleft. This


Tig. 322. Incomplete coioboma (partial) with rests of the pupillary membrane.


form, which commonly coexists with a similar defect in the ciliary body and choroid, is considered as an iridic extension of these defects. Located in any other place a coioboma is called "atypical.” When a coioboma involves the whole visible width of the iris, it is considered total, otherwise it is partial, e.g., a notch of the pupillary margin, a hole (false polycoria or dehiscence - congenital iridodialysis or diastasis) . If the defect affects both mesodermal and ectodermal layers or the entire iris thickness, it is complete, but if only one or the other is missing it is an incomplete coioboma or a pseudocoloboma (see physiologic rarefaction of stroma) (Plates XLV, fig. 4; XLVI, fig. 6) .


798


BIOMICROSCOPY OF THE EYE


In most cases, whether total or partial, colobomas are triangular or pyriform in shape, the apex pointing toward the ciliary border (Fig. 322). Typical colobomas usually tend to be total but their pillars may be spanned by mesodermal strands or bridges. Such a bridge at the ciliary border below may separate the iris defect from that in the ciliary body. The exact appearance of the pupillary borders differs from case to case. As a rule there is a continuation of the seam from the unaffected parts of the iris but the excrescences may be thinned out or flattened in some areas or missing in others. It is not unusual to find the pigment beading defective or missing on one pillar only. In some there may be an irregular hyperplasia of the seam, not unlike an ectropion. Although the stroma is usually normal adjacent to the seam, on one side or the other a narrow whitish line of atrophic tissue may be seen. The frill usually stops sharply at the margins of the coloboma as if it had been cut oflf; in cases in which there is only a notching (partial coloboma) , the frill may continue around the defect and be attached to the seam. The sphincter is usually absent in the region of the defect. Commonly there are remnants of the pupillary membrane attached to the stroma at the sides of the "legs” of the coloboma. Persistent pupillary membranes may be associated with or connected to starlike pigment deposits on the anterior lens capsule or such pigment deposits may occur without the presence of membranes. The edge of the lens (equator) , when seen, may appear crenated or wavy, especially when gaps or defects of the zonule are present. Zonular or tenuous lamellar opacities frequently curve around the exposed equatorial parts of the adult nucleus of the lens. In a case recently seen with similarly situated opaque lens fibers, there was a pyramidal anterior polar cataract.

The pathogenesis of colobomas of the iris is not completely understood but there are two chief possibilities: first, that the defect is primarily ectodermal owing to a local failure in development of a sector of the optic cup margin; and second, that it is primarily mesodermal, owing to the inhibitory effect of persistent capsulopupillary vessels. Mann states: "A number of arguments can be found


CONGUNITAI. ANOMALll-S Ol' THE IRIS


799


on both sides and it Is probable that both types of defect occur, the assigning oi a cause in a given case to either group depending on minute details oi individual structure."

A N IRini A CONGHN ITA

Generally the term "aniridia" would suggest a complete absence of iris, but actually, as indicated by all of the cases of this irregularly dominant hereditary anomaly reported in the literature, some rudiments or stumps of iris tissue were found. Usually a narrow rim of poorly developed iris, either sectorial, or partially or completely annular, forms a pupillary margin. This rim, although markedly underdeveloped, contains both mesodermal and ectodermal elements. However, no sphincter or deeper stromal layer is found. Mann states: "The absence of the deeper portion of the stroma is easily understood since this develops later in response to the need of the sphincter for a blood supply and is presumably initiated by the differentiating rim of the cup. If this failed, the sphinctcric and subsphincteric plexuses and thin layer of feeding vessels would be absent too."

Biomicroscopically the rim or iris stump can easily be seen unless it is entirely hidden behind the corneoscleral margin (Plate XLV, figs, j, 6). However, in most cases if the direction of the beam is widely angulatcd and the patient’s eye abducted or adducted, some vestige of the stump can always be seen. Its presence can also be demonstrated by gonioscopy. Nystagmus often makes examination difficult. The pupillary margin of the iris stump may show normal pupillary excrescences, part or all the way around its margin. Contraction furrows may likewise be present. The major absence of iris diaphragm exposes the margin (equator) of the lens to view as a white line outlined by internal reflection within the lens. The fibrillary-like structures of the zonule are frequently seen making their attachment to the lens just anterior to this area. Frequently, on following the direction of the zonular fibrillae toward the ciliary body, the summits of the ciliary processes can be distinguished.

The interesting things about this anomaly are the defects found associated with it. Although cases have been seen with an otherwise


800


BIOMICROSCOPY OF THE EYE


normal anterior segment, in most instances it is accompanied by other deformities, involving the cornea, chamber angle and frequently the choroid, retina, and optic nerve. In all the cases seen by me the corneal diameter was less than normal. Frequently a peripheral anterior synechia resulting from adhesion of the iris stump to the posterior corneal surface leads to glaucoma. However, it should be emphasized that glaucoma does not occur in every case. Lens defects varying from ectopia to microphakia have been found. Anterior or posterior polar cataracts, coronary, and lamellar opacities are common. In affected siblings aniridia may appear in one individual, while the associated defects may occur in others without aniridia. However, in the latter complete or incomplete colobomas may be present.

In most cases of aniridia the fovea is absent, and as a result there is lowered acuity of vision and nystagmus. Absence of fovea! and macular reflexes can best be demonstrated in examination of the fundus by means of red-free light (Vogt) . The simultaneous affection of the iris (pigment) and the fovea resembles another condition, namely, albinism, in which this also occurs. Both conditions result as a consequence of similar germinal defects. Vogt believes that genetically it is not surprising to find the absent or defective iris pigment linked with retinal (foveal) abnormality since the genes governing these tissues may be in the same or neighboring chromosomes. In many cases, despite the enlarged pupil, photophobia may be absent or minimal.

Today most embryologists believe that aniridia results from a primary ectodermal failure rather than from an initiating mesodermal aberration.

Anomalies of Pigmentation in the Iris

Iris in Albinism, The eye is affected in albinism, either as part of a universal (totally absent) or incomplete universal (relatively poor but not totally absent) congenital deficiency of pigment (hair, skin, or eyes) , or it may be limited to the eye alone (solum bulbi) in which


congi-:nital anomalies of the iris


801


case die general pigmeiuaiion, c.g., hair and skin, is normal/’" Cases of solum bulbi in albinism have been described in which die iris or fundus alone were involved. However, even in those having an apparently normal fundus pigmentation, the macula has never been absolutely normal. In other words, as far as is known, albinism is always associated with a defective macula.

The presence or degree of associated secondary findings, such as underdevelopment of macula, nystagmus, head nodding, or photophobia, depends on or is coincident with the extent of the pigment deficiency or alterations in the retinal pigmented epithelium. Evidently perfect or complete diflcrcntiation of the retinal and choroidal layers depends in part on the presence of pigment but the exact modus operandi of these processes is still unknown.

On the other hand, Mann states: "A normally pigmented individual with coloured irides may show absence of foveal reflex and nystagmus with a normal choroid or with deficient pigmentation of the choroid only. It therefore seems that differentiation of the fovea and pigmentation are related not so much as effect and cause but as two characters which tend to vary together, possibly on account of juxtaposition of the genes.”

Clinically, the appearance of the irides in these cases varies considerably, especially with the manner in which they are illuminated. By direct focal illumination or even diffuse light the color may vary from a light gray (almost white) to a yellow or golden brown. Sur Mnnn, followint; \V;inrdcnbiir;j, wlio atlcmplcd to bring order to the chaotic variations observed, classified alliinism into seven types, as follosvs: (i) Universal albinism. The individual is totally deficient in pigment and shows underdevelopment of the macula and secondary nystagmus. The inheritance is that of a simple recessive. (2) Incomplete universal albinism. The patient is poor in pigment though this is not totally absent. The macula is usually underdeveloped. There may be head nodding, but nystagmus does not occur in all cases. The condition is a simple genetic recessive or an irregular dominant. (3) Isolated eye or fundus albinism. The general pigmentation is normal, the eye alone being deficient. Sometimes the iris is involved; sometimes only the fundus. The macula is underdeveloped. There may or may not be nystagmus and head nodding. The condition is a sex-linked recessive. (4) Aplasia or hypoplasia of the macula with or without deficient fundus pigmentation. This type behaves as a simple recessive, a sex-linked recessive, or an irregular dominant. (5) Aplasia or hypoplasia of the macula and the periphery of the retina with night blindness and diminution of the visual field. This is a simple recessive. ( 6 ) Nystagmus with high myopia and poor visual acuity (probably defective macula) but with normal pigmentation. This is a dominant. (7) Primary hereditary nystagmus without defective macula or albinism. This may be a recessive, a sex-linked recessive, or an irregular dominant.


PLATE XLVI


Fig. I. Albinism - ^brown iris.

Fig. 2, Albinism - blue iris.

Fig. 3. Melanosis occuli - right eye.

Fig, 4. Unaffected left eye. Same case as Figure 3.

Fig. 5. Sector of iris melanosis. (Diffuse illumination; high power.) Note the stars.

Fig. 6. Complete coloboma of the iris. Zonular fibers are seen in the area of the defect.


802



CONGl-NITAL ANOMALII-S OF THE IRIS


805


face malanophorcs in ilic iris may develop in an albino during childhood; in many normal individuals a blue or gray iris changes in color owing to the development of melanophores as late as 8 years of age. W'^hatever the actual hue of the albinotic iris by diffuse illumination, retro-illumination or transscleral illumination reveals features that are unmistakable, since the presence of a moderate amount of melanophores in the anterior border layer of the iris is not obstructive. It is the absence or deficiency of retinal pigment in the posterior iris layer that permits almost perfect transmission of light through the stroma by retro-illumination (Plate XLVI, figs, i, 2). The reflected light from the lens outlines the trabeculae and the vessels. Fine superficial reddish vessels are frequently seen paralleling the radial trabeculae. These are also visible by direct focal illumination which, however, docs not bring out the thicker walled, deeply situated vessels. On the other hand, transillumination of the latter gives the stroma a reddish hue. Also, by retro-illumination, deficiency of the retinal pigment frequently results in the appearance of radial light streaks, peripheral to the lesser circle. These streaks may represent the retro-illuminatcd system of structural furrows (see page 735). Likewise, when the pupil is partially dilated, a series of closely placed radial light spaces or lines can be seen. These spaces or lines probably outline the fine shallow grooves in the pigment epithelium, normally found on the posterior surface of the iris, extending from the pigment excrescences peripherally for a short distance. When the pupil is small, these lines are so close to one another that it is no longer possible to distinguish them separately. Vogt has described a dark semilunar line seen in retro-illuminated albinotic irides, which runs concentrically with the pupil and changes its location or moves according to the direction of the beam. Consequently, he believes that this line is not due to any structural change in the iris but results from an optic phenomenon (reflection and refraction) from the edge of the lens. This line has also been observed in cases of iritis or iridocyclitis when extensive and progressive depigmentation has occurred.

The typical ("rabbit’s pupil”) reflex of the pupil seen in ordinary


806


BIOMICROSCOPY OF THE EYE


daylight illumination, owing to the absence or deficiency of pigmentation in iris and fundus and the consequent unobstructed passage of light through the iris and sclera, causes a pink or red glow to be seen by the observer. The red color of the glow in the pupil is due to reflection from blood in the vessels of the retina and choroid. This phenomena is accentuated by the focal beam.

Melanosis hid is. Hyperpigmentation of the iris (true melanosis iridis) occurs in melanosis bulbi, a condition characterized by increased pigmentation of the uveal tract, sclera, and occasionally of the optic nerve papilla. Its occurrence in fair or lightly pigmented individuals is rare.

Since this condition is preponderantly unilateral (90 per cent of cases) it offers little difficulty in diagnosis. As it occurs normally in pigmented races, melanosis, if present, is found at birth. The scleral pigmentation in the form of slate-blue irregular patches is distinctive. As a rule the fellow eye tends to be hazel (lightly pigmented) in color. However, in rare cases it may be blue or gray, so that a relative heterochromia iridis may result. The area of hyperpigmentation may be limited to a sector of the iris surface or it may be so extensive as to involve its entire anterior face. The affected area always appears darker by diffuse illumination (especially by daylight) than it does by direct focal or by intense afocal or diffuse illumination afforded by the biomicroscope. With the latter method of examination the overpigmented parts may even appear yellowish. The point to be emphasized is the density and profuseness of the pigmentation which approaches that of the normal spongy type seen normally in the Negroid iris. The layer of dense pigmentation may obscure the surface markings and the trabeculae outlines, giving the iris a thickened, smooth, and velvety appearance. However, with higher power, in most instances a system of peculiarly characteristic starlike formations is distinctive and is not found either normally in any race or in any pathologic condition (Plate XLVI, figs, i, 2).

These stars or verrucosities are only seen in the area of hyperpigmentation and are generally more numerous distal to the lesser circle.


See Volume I, page 155.


In some eases groups of closely packed perfect starlike figures are formed, having from 6 to 13 radiating projections (Koby), while in others the center of the vcrrucosity may resemble a tiny round mound, surrounded by a narrow dark ring from which short lines radiate. As a rule the centers of these formations are lighter in color than the hyperpigmented background and hence stand out almost whitish by comparison. In a way, they might be likened to the reflections of a star sapphire. No adequate histologic study of these structures has yet fully explained their clinical appearance, and consequently they are still regarded as resulting from an aggregation of melanophorcs. Reese (1925) found groups of condensed and heavily pigmented melanophores.


20 Inflammation of the Iris

The iris, considered as the most anterior extension of the uvea, receives its blood supply chiefly from the long posterior ciliary vessels. These vessels give off no branches until they reach the posterior portion of the ciliary body. At this point, together with perforating branches of the anterior ciliary arteries, recurrent or retrograde branches supply the anterior portions of the choroid, while anterior branches go forward to form the circulus iridis majoris. The ciliary processes and iris receive their supply from this major circle. The venous drainage of anterior parts of the uveal tract (anterior choroid, ciliary body, and iris) and Schlemm’s canal ultimately pools in the vortical veins. The high degree of vascularity of the uvea makes it vulnerable to the noxious effects of circulating toxins, viruses, or bacteria.

Because of a common nutrient supply and drainage system it is understandable that an inflammatory involvement, even though at first localized in one part of the anterior uvea, e.g., the iris, will extend by continuity or contiguity to the other parts. Even in cases of so-called pure cyclitis in which the major sign of iritis (synechiae) does not occur, indications of changes in the iris (atrophy) may be seen with the biomicroscope later during the course of the disease. Similarly there is definite proof that iritis is always associated with some degree of cyclitis and to a lesser extent with anterior choroiditis, and therefore is better termed anterior uveitis. Unfortunately there are no means at our disposal to examine the living ciliary organ directly; hence we can only infer the presence of inflammation in this body by the presence of exudative cells in the anterior chamber or vitreous. The rest has been gleaned histologically from eyes for


808


INFLAMMATION OF THE IRIS


809


the most part so badly damaged as to have required enucleation. However, in the cases of inflammations of the iris, the biomicroscope is of incalculable value since it affords a better means for its direct observation and permits us to detect disturbances not only at 'the onset but also to observe them through their entire course to the final evaluation of the damage sustained. One should like to be able to state categorically that by biomicroscopic examination alone it is possible in every case to make a positive differential diagnosis, but in certain instances a differential diagnosis may require a survey that includes the employment of every diagnostic method known to medical science. The mere faculty of being able better to visualize the morphologic aspects by biomicroscopy has immeasurably added to our abilit}’’ to make a differential diagnosis. For example: in an acutely inflamed eye, even fi*om the very beginning interstitial keratitis can be differentiated b)’’ the corneal changes. In inflammatory glaucoma, the type of injection, condition of the cornea, size of the pupil, and depth of the anterior chamber quickly suggest that the intra-ocular pressure should be measured. Also an acutely developing shallowness of the anterior chamber may indicate the presence of an intra-ocular tumor. In my opinion, the ability to detect the presence of intra-ocular involvement by means of the aqueous flare is in itself one of the foremost diagnostic achievements. It is not within the province of this work to go into an extensive discussion of the etiologic classification of inflammatory diseases of the iris.'*' According to Woods, "Endogenous uveitis may con

The reader is referred to Duke-EIder's splendid chapter on diseases of the uveal tract in Volume III.’’®- Under the heading of the general etiology of uveitis he classifies them as follows:

1. Exogenous infections, derived from without, induced by (a) organismal infection, through a perforating injury or nick of the cornea or sclera (wound infection), (b) intraocular parasites, and (c) poisonous chemical, animal, or vegetable material.

2. Secondary infections affecting the uveal tract by continuity, or arising from some intraocular event.

3. Endogenous infection, the uveal tract being affected primarily from some cause operating elsewhere in the body.

In summarizing the relative frequency of the causes of endogenous uveitis (among adults in Great Britain) Duke-Elder rates focal infections (teeth, tonsils, and prostate) as first; tuberculosis (focal type) second; syphilis, third; metastatic lesions, fourth; acute infections and exanthemas, fifth; and skin diseases, sixth; while in a large residuum of cases the etiology is obscure and undetermined. However, it is doubtful whether in the present state of our knowledge such a classification is entirely valid. Continental European writers still hold that tuberculosis is the main cause of endogenous uveitis.


810


BIOMICROSCOPY OF THE EYE


veniently be divided into three different groups: (i) sympathetic ophthalmia and the so-called endophthalmitis phaco-anaphylactica; (2) the various metastatic purulent infections of the eye which arise from direct infection by blood-born bacteria; (3) the usual nonpurulent uveitis, iritis, or choroiditis, which so often is recurrent, and comprises the greater percentage of all uveal disease.”

Woods states further: "The older writers divided disease of the anterior uvea into the 'serous’ and 'plastic’ iritis. To my mind a much better terminology is 'nongranulomatous’ for these terms give an indication of the underlying pathologic process. In some instances it may be difficult or even impossible to make this differentiation, but as a rule the clinical pictures as well as the underlying pathology of these two forms of inflammation are quite different. The salient characteristic of these forms of uveitis are as follows:

^^Non Granulomatous Uveitis. In the anterior uvea the onset is usually acute, rather than insidious, and ciliary congestion is marked with pronounced photophobia and lachrymation. The inflammatory reaction in the iris is usually slight and is limited to loss of luster, blurring of the iris pattern, and dilation of the capillaries. There are no nodules and but little tendency to the formation of posterior synechiae unless there are repeated recurrences. The aqueous ray is usually intense due to the outpouring of serum and there may even be a heavy gelatinous fibrinous exudate in the anterior chamber. The deposits on the posterior surface of the cornea are small and pinpoint, and are composed chiefly of lymphocytes. Heavy, greasy exudates do not occur, and there is little or no tendency to capsular clouding of the lens. Koeppe nodules are never observed. The course of a nongranulomatous iritis is usually short and the eyes usually recover with amazingly few residua. Only after repeated attacks is organic damage done to the eye.

"Gi-amilomatous Uveitis. In the anterior uvea, the onset of the granulomatous iritis is usually insidious. The cellular reaction in the tissues is greater than the vascular reaction, and the ciliary congestion is not usually severe. Organic changes take place in the iris with thickening of the stroma from cellular infiltration with blurring of


INFLAMMATION OF THE IRIS


811


the iris pattern and loss of the normal luster. Well defined nodules or tubercles on the surface of the iris, or diffuse localized thickenings suggesting nodules deep in the iris stroma, are sometimes present. There is a marked tendency to the formation of posterior synechiae, with greasy exudates on the anterior capsule of the lens and capsular clouding. The keratic precipitates are of the so-called ‘muttonfat’ variety, and histologicall)’^ consist chiefly of epithelioid cells. Koeppe nodules, or accumulations of epithelioid cells at the pupillary border of the iris, are not uncommon. The aqueous ray may be intense, but more often is rather mild.”

Also in discussing iritis as an entity, one cannot alwa^'^s disassociate the concomitant ciliary involvement and during the acute phase the effects of any increase in intra-ocular pressure. From the viewpoint of biomicroscopy we shall limit ourselves to certain more or less chronologic or episodic inflammatory reactions occurring in the iris and which in most cases are not directly related to any specific etiology. However, it must be admitted that at times, certain welldefined patterns do appear, even in iritis, arising from endogenous causes, which will provisionally at least permit us to venture an etiologic diagnosis on clinical appearance alone, e.g., the nodules in tuberculous iritis, the hemorrhages and gelatinous exudates in gonorrhea, and circumscribed lesions in herpes, the luetic roseolae of the iris, etc. Consequently in such instances special descriptions will be given.

Naturally, the time of appearance of the lesions seen with the biomicroscope will depend on the type and the acuteness of the process. In certain fulminating forms the e^'^e from the start may be so overwhelmed by the inflammation that edema and exudation, especially as they affect the cornea, make it impossible, except perhaps at the very outset, to observe any orderly sequence of events as they occur in the anterior chamber and iris. This is especially true not only in severe secondarj'- forms, e.g., those secondary to infection in other parts of the eye such as the cornea (keratitis or serpiginous ulcer with hypopyon) , lens, or vitreous body, but also in the severe primary types, e.g., acute hemorrhagic iritis or with the fulminating


812


BIOMICROSCOPY OF THE EYE


acute purulent infections following a perforating wound or metastatic extension due to a bacteriemia in meningitis or pneumonia. These, from the beginning, may simultaneously involve part or all of the uvea, and depending upon successful localization of the process to the anterior or posterior segment may result in partial or complete obliteration of the anteripr chamber in the former or to the formation of a vitreous abscess in the latter. In both, depending on the damage, the attendant sequelae may result in destruction of the eye through glaucoma or endophthalmitis. A rapid generalized purulent extension may result in a devastating panophthalmitis.

Frequently what starts out as a localized primary endogenous iritis may by extension develop into a serious form, either acutely, subacutely, or chronically resulting in endophthalmitis, secondary glaucoma, and ultimately an atrophic globe. This is the picture frequently seen in the granulomatous variety, particularly in tuberculosis.

The so-called chronic iritis usually is the result of minimal recurrent acute attacks, punctuated by periods of quiescence. The condition may remain localized to the anterior uvea (iris and ciliary body) for a long period of time before it affects deeper parts of the eye, or it may heal and remain stationary. Although the inflammatory symptoms (congestion and pain) may be slight, in the end great iris tissue damage from organization of exudates (adhesions) , nodules, and atrophy results. Synechiae, anterior peripheral as well as posterior, lead to glaucoma - while the passage of toxins into the ocular fluids leads to changes in the lens and retina and ultimately to atrophy of the eyeball. The corneal involvement in iritis has already been referred to in Vol. I. Depending on the severity, chronicity and changes in intra-ocular tension, variations from transient corneal edema to permanent corneal opacifications may occur. In the same manner, all degrees of scleritis and episcleritis may at times develop. Chronic iridocychtis leads to secondary disease of the lens and cataract formation. This may be initiated by affections of the capsular epithelium, evidenced by the not too infrequent appearance of anterior subcapsular cataract. Hyperemia of the iris and ciliary


INFLAMMATION OF THE IRIS


813


body, together with exudation, causes variations in the intra-ocular tension. Not only does the quality of the aqueous (albuminous content) change but also its quantity. In acute cases reabsorption of the inflammatory products occurs quickly and there may be no changes in intra-ocular pressure. However, with excessive amounts of exudation, especially with recurrent or long standing processes, blockage of the drainage system results in increased intra-ocular pressure. In such cases the chamber may actually be deepened. But as secondary pathologic changes develop in the angle, e.g., swelling of the iris root or the extension of granulomatous processes from the iris or ci/iary body, anterior peripheral synechiae lead to a shadow anterior chamber. The early stages of cyclitis on the other hand may even be accompanied by hypotony. Although the aqueous is highly plasmoid, slowing of the circulation in the ciliary body can result in a reduction in the quantit)'- of aqueous. If such a condition endures for a long time (prolonged hypotony), atrophy of the globe ensues.

The granulomatous infections, e.g., tuberculosis, lymphogranuloma venereum, Boeck’s sarcoid, brucellosis, lues, sympathetic ophthalmitis, perhaps special fungus and virus infections, are the chief etiologic agents in these complicated types of iridocyclitis. However, even these may cause only mild or abortive attacks.

Most cases of acute endogenous (nongranulomatous) iritis run a milder course and have a favorable prognosis. Depending on the intensity of involvement together with the natural resistance of the individual, its duration may vary from one to ten weeks. Reabsorption may be so complete that except for an occasional adhesion (posterior synechiae) or a pigment clump on the anterior lens capsule, no residual evidence of iris inflammation may be found. As a rule it is only in untreated cases of this type that a seclusio pupillae with its attendant sequelus (glaucoma) results.

In general, the biomicroscope will reveal features that are of the greatest diagnostic import, especially at the very onset of iritis or iridocyclitis, and particularly in the nonsuppurative exudative types. The latter include the specific or nonspecific acute, subacute or


814


BIOMICROSCOPY OF THE EYE


chronic forms, usually of endogenous etiology; in these forms the iris itself is nearly always accessible to biomicroscopic inspection throughout their course. In discussing exudative inflammations of the anterior uvea Duke-Elder aptly states "... it is to be remembered that although many of these inflammations are called acute - and rightly so for their symptomatology and course may be exceedingly acute - in the pathological sense this, too, is an inaccuracy, for in contradistinction to the suppurative processes, the exudative inflammations of the uvea are all characterized by the mononuclear infiltration associated with subacute and chronic processes.”

The pathologic changes of the iris have been classified as vascular (hyperemia), exudative, pigmentary and atrophic. Generally at the earliest stages, from the standpoint of biomicroscopy of iritis, exudative changes are a more reliable and prominent feature than the others. For example, in brown irides congestion of the vessels indicative of hyperemia, one of the earliest changes in inflammation, may not be visible. Consequently, at the onset of an acute iritis the presence of exudation is a sine qua non. Exudation is recognized by the presence of an aqueous flare, cells in the anterior, posterior, or vitreous chambers, keratic precipitates, *•' efflorescences at the pupillary pigment margin (ectodermal) which when posterior organize and may form synechiae and efflorescences and nodules within or on the stroma (mesodermal) itself away from the pupillary margin.f

Hyperemia

Ciliary Injection. As early and striking objective symptoms of acute iritis, visible hyperemia occurs as pericorneal or ciliary injection. The so-called ciliary injection results from a congestion of the anastomosing conjunctival,^ episcleral and scleral vessels, which are derived from the anterior ciliary vessels. Depending on the severity and extent of involvement, gradations of congestion vary

See Volume I. t It is well known histologically that nodules deep within the stroma and even those situated away from the pupillary margin may cause extensive posterior synechiae by extending or rupturing into or through the posterior pigment surface of the iris.

t Extreme congestion of the conjunctiva may be accompanied by chemosis and even redness and swelling of the upper eyelid.


INFLAMMATION OF THE IRIS


815


from a faint pink when slight to a deep purple when the deeper vessels are involved. As a rule the injection encircles the cornea but at times it may be localized to a sector corresponding to the area of greatest iris involvement. For example, the location or point of m.axlmum intensity may correspond to a place where nodules are found. It is also possible that the normal anatomic distribution of the deeper branches of the anterior ciliary vessels may also be a factor in determining where the injection will be most marked. Just as hyperemia and ciliary injection indicate Inflammatory reaction, subsidence of this congestion naturally suggests regression.

Hyljcrciuia of Iris Vessels. Although most of the radial fibers of the superficial iris layers carry blood during fetal life, this function ceases just before birth. We see these structures as the ordinary iris trabecular meshwork unless they are obscured by melanophores, e.g., in the brown iris. With the exception of albinism, blood-carrying trabeculae are rarer than those without vessels. Even in a normal blue or gray iris, only occasional!)’’ is a radial or angulated vascular loop found (Plate XLI, fig. 6). These vessels (probably veins) are either free and unsupported or are bordered by a delicate, whitish sheath, giving the impression that they occupy the central part of a fine trabecula. At times the)'^ may branch and join up with a vessel of another sector. I saw such a vessel in a case in which there was a slight ectropion of the pigment border of the pupil. This vessel, after leaving the periphery, branched in three directions and in extent could be traced over half the iris surface. Both the vessel and ectropion occurred in the same iris sector below and temporally. There were no indications of an inflammatory cause.

Because of their thick opaque walls, the large, more deeply situated vessels are not visible as such biomicroscopically. They may be discernible only after marked depigmentation and extensive atrophy of the iris substance, e.g., ruheosis iridis glaucoinatosa. From the pathologic standpoint, an increase in number and prominence of iridic vessels bespeaks either iritis or venous stasis. The latter is seen in diabetes (rubeosis) , glaucoma, thrombosis of the retinal veins, and


816


BIOMICROSCOPY OF THE EYE

in intra-ocular tumors (including hemangiomata of the iris) (Plate LI, figs. I, 2, 3, 4).

Biomicroscopically, in acute iritis, hyperemia is manifested by the presence of dilated vessels, which as a rule have a radial direction. Such vessels are best seen in the ciliary zone and tend to branch as they approach the lesser circle and pupillary zone. Vessels may be found in several or in a single iris sector, either paralleling the whitish trabeculae or crossing them at various levels in the stroma. Usually they are only seen in blue or gray irides since the heavy obscuring surface pigmentation of the brown iris prevents their detection. Hyperemia of the iris vessels undoubtedly causes some of the color changes seen in inflammation. The addition of red color (from the vessels or from small hemorrhages) to a blue or gray iris will cause a greenish appearance. A light brown iris will turn a reddish-brown. The discoloring effect of hyperemia will, as just mentioned, affect the dark brown iris least. The fact that only a few trabeculae carr)'’ visible vessels, even in severe iritis, indicates that for the most part they completely lose their original bloodcarrying function. At the onset of an acute iritis (in light colored irides, blue or gray) the pre-existing vessels become more visible or previously empty vessel-bearing trabeculae develop a reddish central line indicating the presence of blood. In other cases vessels with no discernible sheath may be seen. These tend to appear in the neighborhood of the collarette or in or near the sphincter zone. Here they may run circularly (concentric to the pupil) or assume a congery of twisted formations. When of fine or delicate outline, the frill (lesser circle) not infrequently will contain blood. In this case the outlines of its arcade-like structure become apparent, ' forming a vascular arc or complete circle circumferential to the pupil. In others small local congeries of vessels (see roseolae and rubeosis, Plate LI) may appear in one or more places in the region of the frill; at times the}^ are irregularly distributed in the ciliary zone. Most of these visibly dilated vessels in cases of simple iritis return to their previous blood-free state as the process abates. But at times such a vessel retains its red color permanently. Recurrent attacks of chronic iritis favor persistence of newly formed vessels.


INFLAMMATION OF THE IRIS


817


As a result of prolonged or severe stasis, perhaps together with atroph)'- of the stroma, iridic vessels may tend to lose their delicate trabecular sheath, and as is the case with new formed vessels, stand out in bold relief to form the picture known as rubeosis iridis (Plate LI, figs. I, 2, 3, 4) . The presence of such vessels in the iris periphery and in the chamber angle leads to the formation of anterior peripheral synechiae and inevitably to secondary glaucoma. In severe exudative granulomatous infections, e.g., tuberculosis of the iris, new vessels may not only invade the iris but may proliferate irregularly over the anterior lens capsule especially when a pupillary exudate is present (Plates XLIX, fig. 7; LI, fig. 7). Pathologically, hyperemia is one of the first reactions to tissue insult. But from the biomicroscopic standpoint, since its presence in the iris may escape detection, e.g., as in a brown iris, one acknowledges this sign as a definite indication of iritic irritation or venous stasis; but for the earliest proof of onset of Iritis; one relies more on the presence of exudate (increased aqueous flare with or without cells or debris) and corneal edema (epithelial and endothelial). I have verified this point many times at the onset of iritis in cases of gray or blue irides in which an outstanding aqueous flare with or without floating cells preceded by days an increase in the number of visible vessels.

In special cases of acute iritis (e.g., gonorrheal and herpetic iritis) hyperemia of the iris itself may be so marked as to constitute an outstanding feature. The extensive vascular engorgement may lead to formation of visible groups of vessels and petechial hemorrhages, and eventually to hyphemia of the anterior chamber (Plate LII, fig. 2). An instance of this was seen in a case of acute iritis occurring in an eye, which five years previously had been trephined for chronic simple glaucoma. Up to the time of the iritis the eye had been entirely free from inflammation, the intra-ocular pressure being stabilized at 12 mm. Hg (Schiotz). With no previous history of conjunctivitis, the patient suddenly developed pain and redness (pericorneal injection) in this eye. On the following day biomicroscopy revealed a distinct flare in the aqueous, containing fibrinous exudate and pigment cells. The miotic pupil was bound down by an exudative membrane in its lower parts. There was no exudate


818


BIOMICROSCOPY OF THE EYE


seen in the operative coloboma above. There were many radiating vessels in the iris stroma visible as reddish lines. However, by indirect light in the pupillary zone and near the lesser circle small bright superficial spots (hemorrhages) were seen. Although predominantly they were situated near the frill, several isolated ones were found in the ciliary zone. A few days later a hyphemia suddenly developed and the eye became hard, extremely congested, and painful. The eyelids were chemotic, the eye was protuberant and had limited adduction. After a few days enucleation became imperative.

Edema. Edema or swelling of the iris tissue itself, with sogginess, obscuration of the delicate trabecular architecture and change in color, is manifested only after the process is well established. Naturally the time of appearance of such changes varies from case to case and depends on the violence or duration of the inflammation. Many writers, in describing the earliest changes of iritis, speak of a variable haziness of the iris surface tissue. Some even imply that they received the impression that a thin veil was present over the iris surface but that this veiling never obscured the trabecular structure. Edema of the iris is difficult to evaluate in the early diagnosis of iritis. I have examined innumerable cases in the earliest stages of inflammation and as yet am not convinced that it is possible to diagnose the presence of early edema. Both the veiling effects of the cornea (which may be more respersive) and an increase in aqueous turbidity interfere.

Exudation. Exudation occurs in iritis not only in the chambers of the eye and on their boundaries but also on and within the iris itself.

Exudation in the Anterior Chamber

Aqueous Flares.'^ Exudation in the form of albumen in the aqueous, with or without the presence of cells, results in the production of a visible aqueous flare (Tyndall phenomenon). This is a cardinal finding at the very beginning of iritis, cyclitis, or anterior choroiditis and to my mind its early detection is one of the most important diagnostic advances afforded by biomicroscopy. Whether or not dilatation of pupil retards the amount of exudation is still a moot point. Gilbert described a case of iritis, which showed only a few efflorescences in front of and behind the pupillary seam superiorl)^ The picture remained unchanged for a week - but when the patient discontinued treatment for a few days, there was a marked increase of exudate. At this time the upper part of the pupil was covered and bound down by the extensive exudate. With renewed atropinization the adhesion separated, and further exudation ceased, so that in a few days the picture resembled that of the earlier state.

Patients frequently seek medical attention because of a slight blush of conjunctival injection. The presence of even a minimal aqueous flare at this early stage warns of an intra-ocular process and dispels any idea that the condition is merel)'^ a simple conjunctivitis - an error frequently made in prebiomicroscopic days.

As the beam traverses the normal anterior chamber, a dark optically empt)'^ area, representing the depth of the anterior chamber, occupies the space between the relucent corneal and lenticular blocks. At the point where the protein content of the aqueous increases (due to exudation) to at least ten times that of the normal, the beam becomes visible as a grayish flare as it passes through the aqueous.*'’ The possibility of a physiologic flare in the normal eye, owing to the slight albuminous content of the aqueous, can be disregarded because of its delicacy and because it is only seen under special conditions. Practically, a visible flare should always be considered as a pathologic manifestation.

The intensity of the flare increases with the degree of aqueous turbidity, so that if one directs the focused beam through a highly turbid aqueous and observes it with the unaided eye, no interruption of the Tyndall phenomenon will be seen from the surface of the cornea to the posterior surface of the lens. In most instances, even when the condition is observed at an early stage, floating cells, indicated by moving points in the flare, will be observed. To see these, higher magnifications of 20 X or more are required.

At the onset, in most cases of uveitis that I have studied the cellu

See Volume I.

820


BIOMICROSCOPY OF THE EYE


lar elements were unpigmented and appeared as grayish dots. On the other hand I have frequently observed that from the very beginning of an iritic attack, even in a blue or gray iris, the cells were pigmented. It is my impression that pigmented cells are more liable to be seen when the inflammatory processes were severe and fulminating. They were common in inflammatory glaucoma. This also held true for keratic precipitates appearing later. However, it should be emphasized that at the present time no definite etiologic or pathognomonic significance can be attached to the color of cells seen in these inBammatory conditions. As a rule the tendency to form large keratic precipitates is more marked in cyclitis than in acute iritis, though exceptions are frequently seen. The appearance of a heavy corneal precipitation, e.g., "mutton fat” clumps, in acute iritis suggests accompanying cyclitis (Vol. L).

Subjectively the presence of an aqueous flare is always accompanied by blurring of vision. This symptom often precedes all others. As the intensity of the inflammatory processes mounts, increasing changes in the cornea will be observed."' These consist of endothelial bedewing, precipitates, folds in Descemet’s membrane, edema of the stroma and epithelium. The summation of these alterations results in a gradual clouding or increase of relucency of the cornea. When this becomes marked, observation of the aqueous flare becomes difficult especially when higher magnifications are employed. In such cases it is preferable to disregard the microscope and to observe the

Invariably, delicate changes are present in the endothelium almost at the very onset of uveal irritation. I had occasion to examine a physician, aged 36, who on awakening became aware of a slight blurring of vision. During the day he noticed a slight blush of the bulbar vessels in both eyes. Biomicroscopic examination revealed a slight increase in aqueous flare bilaterally. In each eye there was a faint stippling of the endothelium in the lower parts of the cornea. The irides appeared normal and except for minimal neuralgic pains about the eyes and the blurring, there were no symptoms. The fundi were normal. On the following day the blurring seemed less and the injection had cleared. After the fifth day the aqueous flare and cells were not visible and the delicate stippling (bedewing and keratic precipitates) of the endothelium in both eyes was absent. He received no treatment either locally to the eyes or systemically, except that he gave a history of having had a subsequent suspicious apical pulmonary lesion. He had had tuberculosis five years before but since then had been perfectly well. Five years later he developed hemoptysis and active pulmonary lesions were again found.

I have also seen minimal reactions of this type in association with a moderate rise in intra-ocular tension in a case which later proved to be one of chronic simple (?) glaucoma. Coinciding with the lowering of tension after the use of miotics the flare disappeared.


INFLAMMATION OF THE IRIS


821


passage of the beam through the anterior chamber with the unaided eye, using the small cylindrical bundle or the slit of 0.5 mm. height. The smaller sized beam cuts down considerably on the interfering dispersion of light resulting from the increased corneal relucency and aids in the perception of the aqueous flare.

Cells in the Aqueous. The ability to detect a delicate increase in aqueous flare at the onset of uveal inflammation may tax the skill of the observer. But the presence of cells at this stage, in either the anterior chamber, retrolental space (anterior vitreous) is a sign of paramount diagnostic significance. Although cells in the anterior chamber can occur physiologically in special instances,'”' as a rule their presence is indicative of an intra-ocular inflammatory reaction. Comparison with the fellow eye, provided it is normal, usually dispels any doubts concerning this sign. I have seen cases in which the aqueous flare was very marked before any individual point-like dots (cells or pigment) were apparent, while in other cases, in which there was an almost completely imperceptible flare, from 5 to 20 cells could be counted, floating with the convection currents.

After a process becomes well established and the inflammatory reaction reaches its height, there will be no difiiculty in verifying the presence of flare or cells, and when the well-marked aqueous flare is examined with higher power, it may be found to be composed of a densely packed stream of points. When the aqueous becomes highly “pl^smoid,” the usual convection currents cease. Resumption of cell movement is an early sign of diminution of the inflammation.f

As previously mentioned, in fulminating cases of iridocyclitis and in such conditions as inflammatory glaucoma, or acute interstitial keratitis, edema^ and cloudiness of the cornea may hamper observation of the anterior chamber or retrolental space; but such hindrance may be overcome to a degree by cutting down on the size of the beam and by persistent observation over a period of time.

- See Volume I, page 434.

t See Volume I, page 568.

t A drop of glycerine placed on the cornea frequently will aid in a temporary clearing of epithelial edema.


S22


BIOMICROSCOPy OF THE EYE


TYPES OF CELLS AND EXUDATE

Pigment. As was previously indicated, in severe cases of anterior uveitis pigmented cells may be observed in the anterior chamber flare. These pigment granules probably come from the pigment excrescences of the pupillary margin (seam) or from the retinal pigment posteriorly; it is not known whether any of this pigment comes from broken-down melanophores during the acute phases of a slight or moderately mild iritis. Destruction of the melanophores probably depends on the location, intensity or chronicity of the iris involvement. In acute inflammatory glaucoma it is not unusual to find a great dispersal of iris pigment in the anterior chamber, on the posterior corneal surface, and anterior lens capsule as well. This may also be demonstrated in the iris after the acute phase has subsided by the appearance of depigmented or vitiligoid areas (Fig. 323; Plate LI, fig. 5 ) . In chronic and dystrophic states, depigmentation of the iris stroma is commonly seen. Pigment granules are also generally found in the aqueous and as deposits on the chamber boundaries immediately after injury to, or following surgery of, the iris. Although pigment granules are found on the anterior capsule as congenital rests (remains of the tunica vasculosa lentis anterior and the retro-iridal lines), their presence on the posterior lens capsule, retrolental area or vitreous generally indicates an antecedent inflammatory process.

Erythrocytes will always be seen in the anterior chamber after hemorrhage. (See Plate XLIX, fig. 2; Vol. I, Plate XXXI, fig. i.) Owing to massing of the cells, hyphema either in the anterior chamber, retrolental space, or vitreous appears bright red in color; whereas the individual red cells seen floating above it are distinctly yellowish in hue. This is especially true in hemorrhages of the vitreous after the cells have diffused through the gel. As time goes on the coloring matter in these cells may be washed or laked out; the points then become whitish. As a rule the deposits from hemorrhage are dustlike in character while those from inflammation are coarser. One should always be cautious in making deductions from


INFLAMMATION OF THE IRIS


823


biomicroscopic appearance of delicate variations in color of cells seen in the aqueous and even more especially in the retrolental space or anterior vitreous.


Fig. 323. Vitiligoid area in iris near operative coloboma, in a case of chronic iritis and secondary glaucoma. Note pigment granules on the anterior lens capsule and scattered over the iris surface.

With higher magnifications errors resulting from refraction and aberration may cause false color changes. The color of a point in the retrolental space or vitreous may vary with the type of light source, type of illumination, or the magnification employed. As a rule, the stronger the illumination and the higher the magnification, the whiter a deposit will be. For example, the red color of blood is seen better macroscopically than microscopically. For these


824


BIOMICROSCOPy OF THE EYE


reasons, when attempting to determine the color of cells, one is advised to observe the beam with the unaided eye or under very low magnification. It is necessary to point out that an admixture of blood cells in a pre-existing fibrinous exudate (iritis) gives the chamber and the iris itself a muddy appearance.

White cells. It is my impression that white cells predominate in cyclitis and in choroiditis. This also seems to be the case in iritis except in certain fulminating cases where the ceils may be pigmented (yellow, brown or reddish) from the outset. However, during the first few days of developing iritis, the cells in the aqueous are whitish but become more pigmented as the process develops (phagocytosis of pigment granules). Consequently, in the very early stages of uveitis one cannot make a differential diagnosis bj'^ the color of the cells alone, or ascertain by this sign in which part of the anterior uvea the inflammatory focus predominates. It is generally assumed that the smallest white dots represent individual white cells and that the larger ones are clumps of white cells.

Fibrinous Exudates. In severe cases of iritis (e.g., gonorrheal iritis) the exudate may agglomerate and may easily be distinguished as dense clouds or even grossly solid masses. Large agglomerations of cells or products of inflammation may sink by gravity to the lower portions of the anterior chamber, e.g., hyphema, hypopyon, solid exudates in severe keratitis, or metastatic masses from neoplasms.

An outstanding example of iritis, in which filiform threads or larger coagula form in the anterior chamber, is the one caused by the gonococcus. Here, the anterior chamber may be entirely or partially occupied by a mass of gelatinous exudate, which may obscure the iris and simulate a dislocated lens (Fig. 324). It is interesting to note how quickly such a jelly-like mass may form and absorb. Within a week such an exudate can appear and disappear, leaving no visible keratic precipitates behind. On the other hand, the denser and more opaque massive exudates seen in the granulomatous infections tend to organize and to become vascularized, thus leading to dire sequelae.

Many authors have stressed the importance of discovering cells


INFLAMMATION OF THE IRIS


825


in the anterior chamber, the retrolental space, and the vitreous in suspected sympathetic ophthalmitis. Butler states it is one of the most valuable features of biomicroscopy “because it allows us to


Fig. 324. Gonoccocal iritis. Large gelatinous mass in the anterior chamber. Two iritic adhesions.


recognize sympathetic ophthalmitis several days in advance of the appearance of the more obvious signs.” In commenting on Vogt’s dictum, that if the slit lamp had no other value than the ability to recognize sympathetic ophthalmitis at an early date, it would justify its cost and the trouble necessary to master its technique, Butler says, “We feel that all who have saved an eye by indications of the slit lamp will fully agree with him.”

Parasites: Onchocerciasis. Through the courtesy of Dr. M. Puig Solanes, I had the unusual privilege of seeing two of his cases in which it was possible to observe microfilaria in the cornea and in the anterior chamber. In a personal communication he stated that corneal lesions are found in 85.7 per cent of onchocerciasis, and that it appears in three clinical forms: (i) as superficial punctate keratitis, (2) as an interstitial keratitis, and (3) as a vascular keratitis. Biomicroscopically it is possible to observe the microfilaria in


826


BIOMICROSCOPY OF THE EYE


the parenchyma of the cornea and in the anterior chamber. In the cornea they can best be seen by retro-illumination. By this form of illumination they appear as elongated filaments of uniform size and


Fig. 325. Parasites (microfilaria) in the anterior chamber (onchocerciasis).

shape. In the anterior chamber they are easily seen in the aqueous flare (iritis generally being present) as thin curved lines, wriggling freely in the aqueous. The ability to recognize microfilaria in the cornea and anterior chamber is an important asset in the diagnosis of this disease (Fig. 325).

EXUDATION (debris AND CELLS) IN THE SO-CALLED RETROLENTAL SPACE

When the nitra beam is sharply focused on the posterior lens capsule a dark intervening space (space of Berger) is seen between it and the vertically folded anterior face of the vitreous proper. When making observations in this area it is preferable to have the angle between the axis of observation and illumination as narrow as possible, and to use the cylindrical or short slit opening of the diaphragm with narrow width of aperture (optic section) .


A more detailed consideration of the anatomy and biomicroscopic appearance of the retrolental space will be treated in the chapter on the vitreous, page 1375


Fig. 326 . Cyclitis. Cellular deposits on the posterior lens capsule, in the retrolental space and vitreous. A band of vitreous is adherent to the posterior lens capsule below.

For purposes of orientation it is advisable to begin observations with objectives of low magnifying power. The finest structures, such as particles and cells, unless obscured by haziness of the intervening optic media, are easily seen as a consequence of the intrinsic magnification induced by the dioptric power of the anterior media (cornea, aqueous, and lens). A cell will appear almost twice as large on the posterior lens capsule or in the retrolental space as it would in the anterior chamber (Fig. 326).

The stronger the illumination, the more relucent Berger’s space appears. With the arc illumination, or even with an overvolted nitra lamp, Berger’s space, visualized as a dark, optically empty band


828


BIOMICROSCOPY OF THE EYE


when ordinary nitra illumination is employed, now appears more relucent (owing to an increase in the intensity of the Tyndall phenomenon). Not only does the fibrillar vitreous structure now appear to have approached closer to the lens but within the retrolental space itself is revealed a delicate fibrillary structure. This would indicate that the substance occupying the so-called retrolental space is vitreous (hyaloid ‘"I, or is derived from the vitreous rather than the aqueous. Hence, we have to consider that exudation in this region and on the posterior lens capsule is part of a general exudation into the vitreous. This is borne out by personal observation in several cases that inflammatory deposits on the posterior lens capsule f are either preceded or at least associated with exudation into the hyaloid vitreous (retrolental space) as well as in the deeper definitive vitreous.

It is impossible to state definitely whether, in inflammatory states of the uvea, exudates (cells or fibrin) appear in the retrolental space before the}’- do in the anterior chamber. According to most writers, the reverse is true. However, in certain instances (sympathetic ophthalmia) it has been reported that depositions in the retrolental area and in the vitreous proper were not only the first to appear but were the only indications of a disturbance. It has been my impression that in iritis exudation of flare, cells, or both, is first seen in the anterior chamber, while in choroiditis (anterior and posterior) exudates (chiefly in the form of cells) are initially found in the retrolental space (vitreous) and on the posterior lens capsule when these areas are accessible to examination. As the inflammatory processes progress, inspection of the retrolental space may no longer be possible owing to corneal haziness and turbidity of the aqueous. Consequent!}^ it may be stated that in inflammatory conditions, examination of the retrolental space will be fruitful in the earliest stages or later during the period of regression when visualization in this area becomes possible; it is also most advantageous in cases of anterior choroiditis when the lesion is so far forward as to fall out of the range of the ophthalmoscope. In the latter instance the presence of cells or exudate in the aqueous as well as in the retrolental space (vitreous) or on the posterior lens capsule may be the only clue of an inflammatory process. The color of these cells may assist in differentiating between hemorrhage and inflammation. As previously described the color of blood cells will vary from bright red to yellow; uveal pigment appears reddish brown while ordinary exudative cells are grayish.


See chapter on vitreous, page 1371. tSee paragraph on inflammatory deposits of posterior lens capsule, page 1217.



As in the anterior chamber where keratic precipitation occurs, exudates in the retrolental space and vitreous proper may be deposited on the posterior lens capsule. It should be remembered that the precipitation of inflammatory products on the posterior lens capsule ordinarily is rarer and much less in extent than that occurring on the posterior corneal surface. Generally speaking, deposits on the posterior corneal surface will be found earlier than those on the posterior lens capsule. Koby does not believe that a correlation can be established between the two. It can be stated only that a keratic precipitate occurs more frequently alone than in conjunction with deposits on the posterior lens capsule, rather than the converse.

Probabl)'" owing to the fact that convection currents behind the lens are absent or are not as marked as those in the anterior chamber (owing to the consistency of the retrolental substance and because there is little or no temperature gradient effective) , the deposits on the posterior lens capsule tend to be more diffusely arranged than they are on the posterior surface of the cornea, e.g., an inverted V. Also one must consider the difference in curvature between that of the posterior lens surface (convex) and that of the posterior corneal surface (concave). The usual deposits on the posterior lens capsule are dotlike, star-shaped, or irregularly angulated. Pigment granules are very common and are frequently noted especially in association with a generalized vitreous pigmentation (e.g., following retinal separation). Further consideration of inflammatory deposits on the posterior capsule will be given on page 1217.

The fate of posterior capsular and retrolental (vitreous) deposits (exudate and pigment) vary. They may be resorbed and entirely disappear, or individual cellular elements (especially in the vitreous


830


BIOMICROSCOPY OF THE EYE


proper) may remain present for long periods of time. When the exudation is massive (as may happen in some of the severe granulomatous or septic infections and in the case of uveal inflammations of infants) organization leads to the formation of dense membranes. Consequent to the formation of thick membranes are the sequelae of shrinkage and atrophy of the globe. Lens opacification frequently precludes biomicroscopic examination of such extensive changes.

Efflorescences and Nodnles. Since the advent of the biomicroscope attention has been called with increasing frequency to the presence of exudative agglomerations in the form of efflorescences or nodules, in inflammatory conditions of the iris and ciliary body. These may occur not only at the pupillary border but also on or in the iris stroma itself, during acute, subacute, or chronic inflammations of the iris and ciliary body, and have even been known to form in cases in which there is no ciliary injection. These exudative lesions are usually not accompanied by any loss of tissue substance.

Histologically these formations range in composition from coagulated fibrin with or without cells (pellucid efflorescences) to the more solid cellular accumulations (nodules) . Vogt found histologically that the nodules were composed of lymphocytes, especially large mononuclear cells, and epithelioid cells, with caseation. In his experiments, animal inoculation with fragments of iris containing nodules proved negative for tuberculosis, although there was involvement of lymph nodes. Biomicroscopically, efflorescences (especially those at the pupillary margins) came into prominence after they were described by Gilbert (1914)^^® and by Koeppe (1917)'’”* and since then, those found at the pupillary border have been commonly known as "Koeppe nodules.” The generalized term "nodule” for these bodies is in my opinion somewhat unfortunate since this term infers a solid structure. Consequently, I feel that the term “efflorescence” or "floccule” is more appropriate for the delicate and almost translucent formations and that the designation "nodule” should be reserved for those appearing more opaque and solid.

In the present state of our knowledge no specific etiologic significance can be attributed to efflorescences or nodes seen in iridocyclitis.


INFLAMMATION OF THE IRIS


831


However, one is tempted clinically at least to venture certain observations concerning them. For example, the smaller ephemeral and translucent efflorescences, especially occurring at the pupillary margin (ectodermal) commonly occur in the acute nonspecific types of exudative iritis and iridocyclitis, whereas the larger more solid or opaque nodules in any location suggest the possibility of a granulomatous process. Excluding a specific etiology, e.g., such as syphilis, leprosy, sympathetic ophthalmitis or Boeck’s sarcoid, European writers are prone to attribute a tuberculous etiology to most cases of iritis or iridocyclitis exhibiting nodes of the latter type, particularly when the process is chronic. Vogt has drawn an analogy between them and the skin tuberculides (Darier) of the extremities and back, and also to the efflorescences in phlyctenular keratoconjunctivitis. It may well be tliat European authors are correct in their assumption that most chronic forms of anterior uveitis which they see, especially those exhibiting nodules, are of tuberculous origin. However, this may not hold true for other countries or other localities. For example, recently it has been shown in this country that brucellosis (an infection that is more widespread than is generally suspected) is not an uncommon cause for recurrent iritis. Also the frequency of uveitis in Boeck’s sarcoid has been noted. Both Heerfordt’s disease (uveoparotid fever) and some cases of Mikulicz’s syndrome may be manifestations of sarcoid. Iritis caused by these infections show no special features biomicroscopically that might distinguish them from tuberculosis.

From the standpoint of their histologic appearance and negative bacteriologic findings, the formation of iris nodes strongly suggests the idea that they are the result of an allergic response."' The lack of uniformity in the description and terminology of these structures is understandable since there is such a great variance in their clinical appearance.

Whatever their physical appearance, nodes have been classified according to their point of origin as ectodermic or mesodermic.

One could be tempted to consider efflorescences (similar to phlycetenules) as a tuberculo-allergic response and the more solid ones (especially the intrastromal nodes) as actual tubercles.


PLATE XL VII


Fig. I. Iritis. Keratic precipitates. Pigment deposits on the anterior lens capsule. Pigmented efflorescences.

Fig. 2. Efflorescence (early).

Fig. 3. Same efflorescence in Figure 2 seen later - pigmented.

Fig. 4. Efflorescences.

Fig. j. Floccules of Busacca (luetic).

Fig. 6. Efflorescences.

Fig. 7. Efflorescence - high-power view of Figure 5.

Fig. 8. Broad efflorescences.

Fig. 5. High-power view of Figure 8 by direct focal illumination.

Fig. 10. High-power view of Figure 8 by retro-illumination.


832



\


INFLAMMATION OF THE IRIS


83 5 Those arising from the retinal pigment Ia)^er, either on the excrescences of the pupillary margin (seam) or just behind them from the posterior surface of the iris, are called ectodermic. Those appearing on the iris stromal surface (flocculcs of Busacca) or within the stroma itself, are known as mcsodcrmic.

Ectodermal Efflorescences and Nodules. Concomitant with the appearance of definite aqueous turbidity and keratic precipitates is the frequent finding of small whitish efflorescences at the pupillary border. These arc located either directly on the intact pigmented excrescences or seemingly arise from the posterior surface of the iris to project themselves into the pupillary area sufflciently to be visible as small, soft, white, translucent fluffs (Fig. 327; Plate XL VII, fig. 2). At times their smooth rounded surfaces remind one of a vesicle. They arc ephemeral, often disappearing within a few days to a week after their onset. Such smooth efflorescences are commonly seen in the early stages of luetic iritis.

Another type of small ectodermal efflorescence, frequently seen in nonspecific iridocyclitis, is the one whose consistency or contour is not unlike that of the large mutton-fat type of keratic precipitate. This form predominantly seems to arise from the posterior surface of the seam and usually is in contact with the anterior lens capsule (Plate XL VII, figs, i, 7, 8, 9, 10) . Although more anteriorly situated ones may lie on the excrescences, those not in contact with the lens capsule are less likely to form adhesions and they tend to disappear at a slower rate than they form. The surface of these lesions is rough and granular and tends, particularly in the case of brown irides, quickly to become dusted with pigment (Fig. 328). According to Meesmann’s conception they are more often found on the lower parts of the pupillary border. For this reason, together with the fact that they are likely to be near the vertical axis, he believes that they are deposited in a way similar to keratic precipitates, namely by the action of the aqueous convection currents and gravity. However, it is generally held that these efflorescences arise de novo in the iris stroma. The more solid efflorescences tend to form posterior synechiae, especially if their posterior surface touches the anterior


836


BIOMICROSCOPY OF THE EYE

lens capsule. If the pupil is dilated, one will frequently see a spot of pigment and exudate at the lens capsule at the original point of contact. In addition, occasionally one may observe a few dilated iris


Fig. 327 Fig. 328

Fig. 327. Efflorescence at pupillary pigment border in early stage of iritis. Fig. 328. Well-formed efflorescence dusted with pigment at a later stage of iritis.


vessels in the neighborhood, although this occurs only at a late stage. However, it should be noted that not all of these efflorescences result in adhesions. The smaller, more anterior ones may slowly disappear leaving no trace. I recently observed a case of acute iritis of unknown etiology in which three grayish efflorescences were found at the lower pupillary margin (the iris was dark brown in color). In about a week they became so heavily pigmented that they no longer could have been identified as efflorescences had this change not been closely followed (Plate XL VII, figs. 2, 3). At this point, on dilatation of the pupil, they simulated the pigmented masses (synechiae) such as those seen adhering to the anterior lens capsule after rupture of a synechial adhesion. Koby was convinced that this form of efflorescence resulted from deposits of inflammatory cells after observing that they formed on a layer of pigment which remained adherent to the lens after iridectomy. Both Spicer and Vogt have observed


INFLAMMATION OF THE IRIS


837


tliem on the anterior lens capsule. Meesmann found them in one case attached to threads of persistent pupillary membrane. In a case of exudative iridocyclitis I have seen similar bodies attached to freely floating strings of fibrinous material in the aqueous. (See Vol. I, Plate XL, fig. 2.)


The larger, more solid appearing structures at the pupillary margin (which in my opinion are not ephemeral as efflorescences) really deserve the name "nodule” (Fig. 329). One cannot, however, be dogmatic concerning the duration of even the solid type of nodule at the pupillary border. Vogt stated that "just as they suddenly appear, these growths may within days again disappear.”

"When large, they may be visible to the unaided eye. Their surface may not be smooth but rather of a granular, crumbly, uneven texture owing to accumulations of cells, and later, melanin. At times conglomerate masses may form by the coalescence of several nodules or efflorescences and may involve a large portion of the pupillary circumference (Plate XL VII, fig. 8). When m contact with the anterior lens capsule they may cause adhesions. This can be verified by


838


BIOMICROSCOPY OF THE EYE


the fact that, on dilatation, pigment and exudate are found on the anterior lens capsule at their former site. In most of the present-day atlases such lesions are called "tubercles” and in subacute or chronic


Fig. 330. Efflorescences and floccules (Busacca) in iritis of unknown origin.


Fig. 331. Two large floccules on iris surface near the chamber angle. In the region of the posterior synechiae there was an intrastromal nodule. Large mutton-fat type of keratic precipitates. Case of Boeck’s sarcoid.

cases have been considered as manifestations of tuberculosis of the iris. As previously mentioned, one must exercise caution before attributing blanket etiologic significance to them.


INFLAMMATION OF THE IRIS


839


Mcsoderiiiic Efflorescences and Nodules. In addition to those at the ectodermic pupillary margin, efflorescences and nodules may appear not only on the stromal surface but also within the substance of the iris. As in the lesions described in the previous section, I prefer to call the smaller translucent agglomerations, “efflorescences” (those that resemble mutton-fat keratic precipitates), the slightly larger and more cystic ones, “floccules” (Busacca) , and the dense, hard ones, “nodules” (Fig. 330). The first two types occur on the iris surface, like deposits, while the nodules may occur not only on the surface but also within the stroma itself (Fig. 331).

In my experience the superficially-placed efflorescences and floccules occur in the acute phases of iridocyclitis whereas the nodules tend to form in the more subacute or chronic cases. I have seen a case (Plate XLVII, fig. 5 ) of acute luetic iritis in which there were numerous white c^'^stic balls (floccules) , seemingly lightly attached not only to the pupillary margin but to various places on the stromal surface. Within ten da^^s they disappeared leaving no trace (syphilids?). Vogt, who considers a large majority of the nodules to be tuberculous, described two mesodermic forms which he calls type I and type II. Type I, which he states are typical tuberculides of the iris stroma, have a homogeneous opaque appearance and may become glassy (Plate LIV, figs. 2, 3, 4). They are best seen in light colored irides where they are lardaceous and white in color, and form sharply delineated homogeneous masses, lying freely on the anterior surface of the iris. In one case they became detached and reached the lens capsule. These structures which contain no vessels are not part of the iris substance but generally lie on it. Type II is found within the iris tissue itself either diffusely or in the form of nodes (Plate LIV, figs. I, 5). The latter thicken and become protuberant, sometimes covered by stroma. With both types, especially as the lesions age, there is a decided tendency for pigmentation to occur (Plate LIV, figs. 3, 4). Such pigment granules, either carried by the aqueous or migrating within the stroma eventually become deposited on the nodules. The strands of iris trabeculae are not visible within the nodules. If diffuse, these formations may easily be overlooked, espe



INFLAMMATION OF THE IRIS


841


ciall)'" if they are situated in the vicinity of the lesser circle. In the latter case indirect illumination of the iris may reveal them as glassy thickenings within the stroma. Here, they may assume various shapes, resembling sausage-like thickenings or more often cupula-like swellings. Such masses may be extremely difficult to visualize in heavily pigmented irides. As a rule they become vascularized. Small red threadlike vessels may be seen in the neighboring stroma or running between the nodules themselves (Plate LIV, figs, i, 5). At times these masses may become so large as to extend to the posterior corneal surface and, especiall)'^ if they arise in peripheral parts of the iris, may cause var)dng degrees of anterior peripheral synechiae which, after organization (Fig. 332), may lead to a fibrous adhesion and obliteration of the chamber angle. Koby has noticed that in such cases, late atrophy of the iris stroma may result in a relative deepening of the anterior chamber, the free angle becoming rounded and obtuse. On the whole, nodules are less frequent in the ciliary zone than in the region of the lesser circle and pupillary area. In general, and ‘depending on size, the intrastromal nodule leaves permanent scarring and vascularization, and is associated with atrophy of the iris. Also as mentioned before, and though diflScult to detect biomicroscopically, histologic preparations have illustrated the manner in which a deeply seated nodule may extend or rupture posteriorly and cause a widespread posterior synechia.

SyiiecJjjae. The classic sign in inflammatory states of iritis is the synechia. It is interesting to note that biomicroscopy has offered little new knowledge concerning the mechanism either of posterior synechiae (adhesions between the posterior surface of the iris and the anterior lens capsule) or of the anterior peripheral synechiae (adhesions between the peripheral anterior surface of the iris and the posterior corneal surface) so thoroughly described (histologically) in the past. It would be impossible to describe all the bizarre types of synechiae. Rarely does one exactly resemble another (Plate XL VIII, figs. 1-9).

The readiness with which adhesions form between the iris and its adjacent structures has caused certain authors to liken the anterior chamber to the peritoneal cavity of the abdomen. Posterior synechiae.


PLATE XL VIII


Fig. I. Synechiae with iris atrophy.

Fig. 2. Two solid synechiae. Lens cataractous. Pupil distorted.

Fig. 3. Atrophic iris with numerous tongue-like synechiae. Indirect retroillumination.

Fig. 4. Toxic iritis. Smearing of the pigment at the pupillary margin. Note circulation hole at upper border of pupil.

Fig. 3. Elongated and stretched synechiae. Note opacity at point of attachment to the lens.

Fig. 6 . Detached pigment particles from the seam adherent to exudative membranes which are connected to the lens.

Fig. 7. Egg-spawn conglomeration of pigment at the seam resulting from detached synechiae (luetic) .

Fig. 8. Synechiae (ectropion in type). Note lens spots.

Fig. 9. Absence of the seam excepting below. Pigment and exudative membranes on the anterior lens capsule. Atrophy of iris.


842



INFLAMMATION OF THE IRIS


845


the form commonly seen in iritis, occur at the pupillary margin where the anterior bulge of lens is in contact with the posterior surface of the iris. The tendency to miosis in iritis assists in a passive way toward adherence by affording a larger area of contact. The miosis and pupillary sluggishness, which according to my observations occasionally follows a brief period of slight initial mydriasis, is due to irritation (spasm) , hyperemia, and exudation in the iris tissue. The actual adhesion, which also tends to keep the pupil small, is formed by exudate from the posterior iris surface which, on organization, produces a seal between it and the lens capsule. Direct adhesions of the iris stroma can occur to the lens capsule, in which atrophic tongue-like processes of stroma are pulled over and attached to a delicate exudative pupillary (capsular) membrane. The seam in these areas will be missing or atrophied. In a case recently observed the membrane over the lens capsule was so thin that at first it was overlooked. However, the presence of pigment granules beneath it on the anterior lens capsule, as seen by optic section, demonstrated that these granules had been deposited before the membrane had formed. How much of a role, if any, free exudate in the anterior or posterior chamber plays in the formation of posterior synechiae is not known. It is conceivable that exudate thrown out by the convection currents of the aqueous, in the narrow zone between the pupillary margin and the lens capsule, might be deposited there (similar to keratic precipitates).

It is not unusual, especially in the acute cases, for the pupil to return to its previously normal size and shape; this restoration, however, is less frequent in the more chronic granulomatous cases, particularly those characterized by the formation of nodules.

As pointed out above, the presence of an efflorescence at the pupillary pigment border does not always presage an adhesion. Those situated at the posterior (lens) side of the seam are more liable to result in synechiae, especially if several of them coalesce. Often, when the pupil is small, adhesions located here will be invisible from in front; their presence only becomes manifest after dilation (following rupture or stretching of the adhesion, either spontaneously or


846


BIOMICROSCOPY OF THE EYE

artificially by the instillations of mydriatics) , when they appear as traction tags or as clumps or dots of pigment adherent to the capsule (Plate XL VIII, fig. 5 ) . With swelling of the iris, in the active stage, it is conceivable that more of the posterior surface of the iris than the pupillary margin contacts the anterior capsule. This may account for the occasional presence of radial lines of pigment dots on the capsule that can only be seen following mydriasis. After the formative periods of adhesions, attempted mydriasis may result in the appearance of a scalloped pupil, since only the part between the adhesions can dilate (Plate XL VIII, fig. 2) . Also, even after organization occurs, an adhesion may be stretched, permitting moderate dilation. Frequentl}'-, after iritis has subsided and there are some remaining adhesions (posterior synechiae) the pupillary movements may not be disturbed since the stroma glides over the fixed posterior pigment layer. This can only occur provided the iris is not too atrophic and the sphincter remains active. If the use of mydriatics is instituted early, adhesions may all be separated, but as a rule they will permanently leave their telltale pigment clumps derived from the pigmented layer, attached to the anterior lens capsule. Corresponding to the size of the pupil before mydriasis and providing that more than one or two adhesions were present, an interrupted circular imprint of pigment on the capsule will leave indelible evidence of a past iritic inflammation (Plate L, fig. i). At times, after the florid stage has subsided, fine fibrinous threads may be noticed, usually pigmented, and resembling residua of the pupillary membrane. These threads, arising either from the pupillary margin or from the pupillary region of the iris, may singly or in a branching way extend to the lens capsule or to an adjoining place in the pupillary part of the iris (Plate XL VIII, fig. 7). Others attached at one end may be found floating freely in the aqueous. Such threads are frequently seen after fetal iritis. They may be attached to flattened polar or eccentric capsular opacities. As these threads, which sometimes may be thickened or ropelike, approach the pupillary edge of the iris, they tend to broaden out. The fact that they broaden out


INFLAMMATION OF THE IRIS


847


(leaflike) and attach to the pupillary pigment seam indicates their inflammatory origin rather than any relationship to congenital pupillar) remnants. In other words the) result from the stretching of posterior synechiae. With miosis, threads of this kind become kinked while after mydriasis they tend to stretch out and become taut (Plate XLVIII, fig. i).

More extensive exudation (in the form of membranes) in this region usually forebodes broader adhesions; in the extreme state an annular synechia may seclude the pupil entirely. Patients who have not had the benefit of local treatment (mydriatics) end up with pinpoint pupils. Obviously dilation of the pupil, if kept constant (a difficult task in acute iritis), prevents the formation of the usual posterior synechiae; but at times the latter will form even when the pupil is dilated. In such cases, when there is associated atrophy of the tissue, the pupil remains wide permanently and loses its reactions (Plate XLVIII, fig. 8).

Traction on the excrescences, themselves, tends to pull them off the iris attachment or to cause their disintegration with the resulting migration of pigment. The synechia itself tends to become covered with this pigment dust so that it soon becomes impossible to recognize any of Its structural makeup. However, all the scar tissue of the adhesions does not necessarily become pigmented. Often a structureless whitish band (broad synechia) or node of organized tissue may be seen attached to the capsule (Plate XLIX, figs, i, 4). These bands may run circumferential to the pupillary edge for longer or shorter distances immobilizing the pupil in part or throughout the extent of the band. The pupillary edge in the region of such bands reveals the absence of normal excrescences, atrophy of the stroma and fine deposits of pigment grains. At times one or more of the excrescences may be attached to these membranes. The attachment of the membranes to the lens is not always smooth but pleatlike so that the filmlike membrane over the capsule is thrown into delicate folds (seen best in the shagreen area, zone of specular reflection) . In other cases the membrane may detach itself from either the lens or iris in such a way that the free end curls over to its place


848


BIOMICROSCOPY OF THE EYE


of attachment. The formation of delicate meshworks of fibrinous exudate on the anterior lens capsule probably results from contraction and organization of exudate. Frequently, thickenings at the places of crossings of fibers forming the net results in starlike structures in which pigment granules may or may not be incorporated (Plate LXXIII, figs. i-6) . Also it is not unusual to see small whitish deposits (threads or stars) on the anterior lens capsule in the vicinity of an adhesion, or even when no synechiae are present.

Migration of pigment may extend into the sphincter zone of the stroma or may be carried to the boundaries of the anterior chamber by the aqueous currents. At the site of the adhesion, especially when it is small, the excrescences are missing, and a slight degree of entropion will be recognized. Annular synechia is generally the result of attacks of plastic iritis. Biomicroscopic inspection will practically always reveal a membranous exudate extending from the iris to the lens capsule (Plate LI, figs, i, 7, 8). Such extensive membrane formation results in occlusion of the pupil with or without seclusion; the membrane frequently becomes vascularized. In ordinary isolated synechiae there is little tendency for vascularization to occur at the point of adhesion although it may be present in the adjacent stroma.

In toxic iritis a smearing of pigment between the pupillary border and the lens capsule may occur (a form of posterior synechiae) (Plate XL VIII, fig.-q) . I have often seen such deposition of pigment at the pupillary border in the iritis that not infrequently follows trephine operations for the relief of chronic simple glaucoma; central vein thrombosis; after retinal detachment; and in diabetes. In retinal separations, iritis and complicated cataract as well may result from the toxic effect of the subretinal fluid which seeps into the preretinal region. This type of "pigtnent-smeared” adhesion is not as apt to be a localized synechia through the medium of an efflorescence as is seen in "infective” iridocyclitis, but is more diffuse. It is possible, according to Vogt, that toxic substances in the aqueous cause suspension of pigment which is in turn deposited. Characteristically, in cases of toxic iritis there is an absence of keratic precipitates. But with secondary infection corneal precipitates are found. This form of


INFLAMMATION OF THE IRIS


849


smeared pigment adhesion may be annular (secJiisio piLpillae) , but usually atropinization demonstrates one free area, generally above, in the form of a circulation hole, often resembling a horseshoe. Such an opening may serve as an adequate communicating channel between the anterior and posterior chamber. A gap (circulation hole) in an almost complete annular synechiae also occurs in chronic types of exudative iridocyclitis (page 897), especially those of tuberculous origin. In these cases smearing of pigment at the pupillary margin (as in toxic iritis) is not found, but thin exudative membranes are seen extending from the pupillary margin over the lens capsule. Vogt has compared the mechanism of "circulation hole” formation to that which occurs in a running stream which does not freeze. In other words it is difficult for exudate to seal off the current in a region where there is active circulation of fluid, especially as the "secluding” mechanism is gradual. The association of toxic iritis and hypotony is interesting.

Nodular formations in the peripheral parts of the iris or exudative fibrinous masses may undergo organization and form anterior peripheral synechiae (Fig. 332 B). These obliterate the chamber angle not only by their volume and mass but also by causing adhesions between the iris stroma and posterior corneal surface.

Pigmentary Changes

As in senility, congenital alterations, or with atrophic disorders, inflammatory states of the iris are characterized by disintegration of its pigment (Plates XLIII, fig. i; XL VIII, figs, i, 3). This is recognized by depigmentation, scattering, and migration not only of the retinal pigment but also of the melanophoric stromal pigment (Fig. 315).

The degree of pigmentary changes (both retinal and stromal) depends on the intensity of involvement, chronicity, local resistance, the original iris coloration, and possibly on the age of the patient. Edematous swelling of the pigment-bearing cells results in their disruption, which is followed by scattering of the contained pigment. Possibly some of the free pigment is phagocytosed by remaining


8^0 BIOMICROSCOPY OF THE EYE

cells. The tendency of pigment to proliferate and the property of these cells to act as histiocytes is well known. A combination of some or all of these factors may serve to explain the pigmentary changes seen in iritis, which if marked cause the iris coloration to change. As a rule in inflammatory lesions the posterior retinal pigment layer is first affected. Depigmentation of the stroma usually accompanies atrophy of the mesodermal iris and may be a later or concomitant manifestation (Plate XL VIII, fig. 9).

Degeneration and depigmentation of the retinal iris layer affects not only the seam of the pupillary border but also, either in part or almost completely, the posterior pigmented iris surface. Examination of the pupillary border in some cases may reveal areas in which the excrescences are missing and other areas of depigmentation not unlike the ordinary senile marginal atrophy. The latter is best seen by retro-illumination, the affected pupillary border being observed by light reflected from the lens as the focused beam passes into the pupil. In addition to atrophy in the regions of posterior synechiae, a secondary increase of pigment may be found. As in glaucoma, attraction of pigment to the pupillarj'- border area (secondary pigmentation) may also occur in chronic cases of iridocyclitis (Plate LI, fig. 6 ). In these, migration of retinal pigment to the pupillary zone of the iris may be marked. Pigment destruction of the posterior iris layers results in a typical moth-eaten appearance when viewed by either retro-illumination or by transscleral illumination. These may be confined to local areas or may become so extreme as to leave only a shell of iris substance behind (Plate L, figs. 4, 8, 9). As mentioned before, except in special cases, in which one can see into the bottom of a deep crypt, it is impossible biomicroscopically to see the posterior pigmented iris layer. When this layer is intact, it does not allow any of the reflected light from the lens to pass back through the iris structure to the eye of the observer. When there is any destruction of the posterior pigment layer, passage of the focal beam into the lens via the pupil allows the reflected light to pass back through the iris at these points (retro-illumination) (Plate L, fig. i ) . This

The deposition of pigment clumps on the anterior capsule following synechiae is discussed on page 846.

INFLAMMATION OF THE IRIS


851


affords a sort of negative image of the lesion (shadow effect) in which lighter translucent areas appear in the otherwise darkened tissue. Such transilluminable areas may be in the form of punctate spots, striae, or may involve a sector of the iris, or the whole iris diffusely.

Owing to the fact that the anterior surface layer may apparently be only slightly involved, diffuse or direct focal illumination of the iris may fail to reveal the amount of atrophy of the posterior pigment layer; thus, unless retro-illumination is used even extensive areas of atrophy may be overlooked. These “holes” of the iris were first described by Oblath (1899) who saw them following iritis in syphilis and variola.

As a result of disintegration, iris pigment granules may be found deposited not only on and in its stroma but also transported by the aqueous to the posterior corneal surface, the chamber angle, and the lens capsule. This occurs spontaneously following iritis and may follow trauma or surgery also. Small residuals of exudates on the lens capsule in the form of threads or stars also attract pigment grains, which change the original whitish appearance. In some cases it appears as if the iris is covered by fine brown or black spots resembling soot. This type of pigmentation is usually most marked in the pupillary zone, but the ciliary zone may show it as well. Extensive superficial iridic deposition of this type may result in a form of heterochromia, A blue iris may assume a dirty yellowish greenish or light brown color while a light brown iris may become darker. One can only speak of heterochromia in these cases provided the iris of the fellow eye is normal.

Localized areas of vitiligo may follow iritis. This results from atrophy of the superficial layers of stroma, especially of the anterior border layer, which in certain cases may entirely disappear. It is most

As mentioned in the paragraph on atrophy (page 857), the formation of such "holes” in the posterior pigment layer must depend to a degree on the stromal affection. It is conceivable that if the deeper leaf of the stroma is affected chiefly, the slighter involvement of the overlying surface tissue may obscure it, to the end that by diffuse or direct focal illumination this part of stroma obscures the deeper destruction. However, indirect illumination will usually reveal a discolored area of stroma overlying these holes or areas of atrophy of the posterior pigment layer.


852


BIOMICROSCOPY OF THE EYE

striking when it occurs in colored irides. Here a whitish area of deeper stroma may be seen, usually sprinkled with pigment granules (Fig. 332 B; Plate LI, fig. 6) . At times the pigment from such areas migrates to and is heaped near the pupillary area. However, localized vitiliginous spots or areas are a more frequent occurrence in glaucoma, especially after acute attacks. I can recall many cases in which this occurred to marked degree following antiglaucoma surgery (Fig. 323 ) . Also it is often noted after simple iridectomy in the region of the pillars. Incarceration of the iris pillars predisposes them to vitiliginous changes. High intra-ocular pressure probably results in pressure necrosis of the tissue. Vogt has shown that such increases of pressure also affect the lens in that damage to the capsular epithelium may be the forerunner of glaucomatous cataract. A varying degree of depigmentation of the iris is also common following trauma, particularly after perforating injuries.

The occurrence of disintegrated iris pigment in the angle of the anterior chamber has been known histologically for a long time and recently has been verified gonioscopically. However, the importance of this finding in regard to the etiology of glaucoma (primary or secondary) is still undecided (see Vol. I) .

Disintegration of red blood cells after trauma or hemorrhagic iritis may also result in dispersal of hematin and changes in iris coloration (see Herpes, page 871).

CHANGES CONSEQUENT TO IRITIS AND IRIDOCYCLITIS

It happens not infrequently that after subsidence of an attack of iritis or iridocyclitis no macroscopically visible changes remain; however, it is very unusual not to find some residual microscopic alterations. The importance of biomicroscopic examination for this purpose cannot be overemphasized. The presence of pigment deposits on the anterior lens capsule, especially those near the pupillary margin, is ver)'- significant. These deposits usually have the form of rough clumps, but occasionally dotlike pigment grains may be seen arranged irregularly or in the form of stars, rings, or radial lines (Plate LXXIII, figs. 1-6). Dilation of the pupil is frequently necessary to


INFLAMMATION OF THE IRIS


853


disclose the finer ones, which may derive from the ridges of the posterior iris surface, and may be bound to the lens capsule by delicate exudates. Close observation of the pupillary pigment seam may disclose atrophy of the border or absence of an excrescence or two in the neighborhood. Exudate deposited on the anterior lens capsule, especially near the pupillary margin, may after a time become transformed into fine threads (by contraction) or starlike figures. When delicate, these may only be seen biomicroscopically.

More rarely, a few fine pigment grains (keratic precipitates) or dots of fibrin may be found on the posterior corneal surface long after the inflammation has subsided. However, in recurrent iritis with marked exudation or in long standing chronic cases (granulomatous) , keratic deposits may remain permanentlj^

Ordinarily the tendency toward the absorption of exudative keratic precipitates is great but, as previously mentioned, older residua (especially in iridocyclitis) become crenated and pigmented. Also the larger mutton-fat-like and plastic exudates tend to leave areas of increased relucency not only on the posterior corneal surface but in the deeper layers of the corneal stroma itself. A notable example of this is seen in the iridocyclitis associated with interstitial keratitis. (See Vol. I, page 500). Examination of the posterior lens capsule and vitreous may also reveal precipitates and pigment even in the so-called "light” cases (Fig. 326). It goes without saying that the presence of posterior synechiae, which may be seen grossly with varying degrees of immobilization of the pupil, is immediately diagnostic of a past iritis. However, severe single or recurrent attacks of iritis as well as the low-grade chronic forms are generally characterized by changes within the iris tissue itself. From the standpoint of biomicroscopy they result in (i) pigmentary changes and (2) atrophy of the iris stroma itself.

Iris (Stromal) Atrophy (Postinflammatory)

Atrophy of the iris stroma not only occurs as a sequel to severe recurrent or chronic inflammations (iritis) but also follows trophic


See Volume I.

PLATE XLIX


Fig. I. Localized area of iris atrophy. Broad adhesion with exudate. Viewed by retro-illumination and direct focal* illumination.

Fig. 2. Radial areas of iris atrophy - ^high-power view.

Fig. 3. High-power view of the lesion seen in Figure i. Diffuse illumination.

Fig. 4. Details of broad adhesion seen in Figure i.

Fig. 5. Iris atrophy of the pupillary margin and stroma. Retro-illumination.

Fig. 6. Atrophy of the pupillary border and stroma. Rarefaction and condensation of the stroma. Posterior pigment layer showing through. Diffuse illumination; high power.

Fig. 7. Chronic iritis. Iris atrophy with vessels migrating over the anterior lens capsule. Retro-illumination.


854



INFLAMMATION OF THE IRIS


857


disturbances, trauma, and increased intra-ocular pressure. Senile atrophy, which in a sense may be considered as physiologic, is discussed on page 771. In general, the changes which produce this picture of iris atrophy are due first to pigment degeneration (and the secondary dispersal of pigment granules) and second to alterations within the stroma itself. The pigmentary changes which are discussed on page 849 involve not only the posterior ectodermal iris layer but also, especiall)'^ in the colored iris, the stromal pigment. Depigmentation of the posterior iris layer results in "holes” or areas of lesser optical densit}'- illustrated by transpupillary retro-illumination (Plates XLIX, figs, i, 7; L, figs, i, 3, 6, 9). This occurs not only at the pupillary margin but also in a regular or irregular fashion, either sectoriall) or completely, anywhere on the entire extent of the posterior iris surface. Examination by direct focal light may ordinarily fail to reveal atrophy of the posterior pigmented iris layer; the overlying stromal layer, which may only be partially affected, diffuses the light and prevents observation of the holes. Considering the fact that the posterior pigmented layer receives its nutrition from the stromal vessels, it would seem that interference with these vessels, either primarily or as a result of stromal involvement, would of necessity cause changes in the underlying pigment layer. This is reminiscent of a similar relationship between the choroid and retina; the layer of pigmented epithelium and outer retinal layers are nourished by the choroidal vessels and hence react secondarily to affections of the choroidal circulation. The formation of these areas of posterior pigment degeneration (holes) after iritis depends not only on interference with the circulation, but mechanical factors also play a part because fixation of the iris by synechiae favors atrophy by traction. Undoubtedly, localized areas of atrophy involving the stroma and the posterior pigment layer as well can follow resolution of nodules (especially tubercles) and papules. Indirect illumination at times will better demonstrate the stromal changes over such a depigmented area than direct focal illumination.

Degenerated pigment granules may migrate and may be deposited within or on the iris stroma, or they may be transported by aqueous


PLATE L


Fig. I. Iris atrophy. Surgical coloboma. Pigment on the anterior lens capsule. Anterior complicated cataract. Retro-illumination.

Fig. 2 . Detailed view of changes following iritis. Temporally, the iris stroma is condensed and flattened. New vessels. Crypts obliterated.

Fig. 3. Brucellosis. Areas of iris atrophy.

Fig. 4. Marked atrophy of the iris - complicated cataract.

Fig. 5. Fleterochromia iridis syndrome of Fuchs. Keratic precipitates. Aqueous flare. Complicated cataract. Atrophy and discoloration of the iris.

Fig. 6. Vitiligo of the iris - Herpes.

Fig. 7. Localized area of atrophy with marked loss of iris substance following iritis.

Fig. 8. Diffuse view of iris following sympathetic ophthalmia.

Fig. 9. Same case as Figure 8. Viewed by retro-illumination. Pupil secluded. Vessels extending over the anterior lens capsule. Complicated cataract.


858




INFLAMMATION OF THE IRIS


861


either out of the globe or to any portion of the chamber boundaries (Plate XLIX, fig. 6). Depigmentation of the stromal melanophores is best seen, as would be expected, in brown irides. In the latter localized vitiliginous spots or a generalized depigmentation of the surface stroma may be found involving a sector of the iris or its whole surface (Fig. 332 B, C). Depending on the extent and degree of depigmentation, color changes result. In some dark brown irides, vitiliginous areas appear dirty white and structureless; but usually these areas are sprinkled with fine pigment granules (Plate LI, fig. 8). While in others, in which the anterior leaf is chiefly involved, the exposed depigmented areas reveal whitish or bluish radiating trabeculae (Plate L, figs. 6, 7). Deeper destruction may expose the posterior iris pigment layer covered by a few completely or partially depigmented stromal fibers. At times a few free trabecular fibers may float loosely in front of the atrophic area or they may form an irregular mat. As a rule, in postinflammatory iridic stromal atrophy only certain sectors in an individual iris will reveal extensive destruction of tissue (i.e., where the lesion had been most intense), the neighboring areas showing relatively fewer degrees of atrophy (Plate L, figs. 6, 7) . An atrophic sector of the stroma may extend from the periphery to the pupillary margin (including the seam) or only the pupillary or ciliary part themselves may be involved.

In atrophy of the pupillary zone, owing to the thinness of the stroma, it is frequently possible to see the brown areas of the posterior iris layer (Plate XLIX, fig. 6). This thinning and rarefaction in the pupillary zone may become so extensive as to permit an uninterrupted view of the posterior pigmented layer, a condition which may be mistaken for ectropion. However, a few stromal strands and the irregular line of the lesser circle usually remain. Vogt has termed this change, resulting from inflammatory atrophy of the stroma, as "circumpupillary exposure of the retinal iris layer.” In other cases the atrophic pupillary zone, sometimes the whole iris surface, may be sprinkled with fine black spots of pigment resembling soot. These dark grains may also be deposited on the posterior corneal surface. Likewise, pigment which is freed in a vitil


862


BIOMICROSCOPY OF THE EYE

iginous process of the iris (especially after acute attacks of glaucoma) may by their weight be deposited in the bottom of the anterior chamber similar to a hypopyon. Vogt called this melanohypostasis.

In lighter colored irides the depigmented area may appear greenish, yellowish or whitish. These types of stromal depigmentation are also seen in glaucoma and after virus infections, e.g., herpes, variola, certain exanthems and the like. The close association between pigment and nervous tissue is of interest in this connection. Atrophy of the iris stroma itself produces a variety of clinical pictures depending not only on the type or intensity of the involvement but also on the original coloration and structure. In dark brown irides with little visible trabecular structure, modification of the surface markings and thinning and flattening may be the only changes noticeable. More extensive damage results in stromal depigmentation and the appearance of vitiliginous areas. Vitiliginous spots may appear in the stromal periphery with no apparent alteration or destruction of the pupillary pigment.

Stromal atrophy is best exemplified in blue or light colored irides, especially if the pupil is not dilated. The iris appears thin and the surface flattened and condensed to one plane, so that the normal difference in thickness between the pupillary and ciliary portions no longer is apparent (Plate XLIX, fig. 3 ) . The trabeculae are stretched out and pulled in a radial direction. The line of the lesser circle (frill) which usually runs concentrically to the pupil tends to become angularly elongated and to be retracted peripherally*’’ (see Fig. 332 B and C). At various places between the stretched fibers, reddish threadlike vessels will be seen. The fibers lose their fluffy appearance and appear frosted. The crypts become less prominent or are obliterated (Plate L, fig. 2). The atrophic trabecular fibers appear whiter, especially in the ciliary zone where the condensation of the anterior and posterior leaf will prevent the diffraction phe

This picture is contrasted to a type of iris atrophy seen in absolute glaucoma in which atrophic changes in the pupillary zone result in a narrowing of this zone (dilation of the pupil). Here a widening (ectropion) of the pupillary seam is seen, and the frill is drawn closer to the pupillarj' margin. Atrophy (necrosis .^) of the ciliary zone of the iris may be so marked as to expose the white sclerotic arterial walls and also dilated and tortuous red veins (glaucomatous rubeosis).


INFLAMMATION OF THE IRIS


863


nomenon that ordinarily gives the iris its bluish tinge. However, because of its thinness the pupillary area (its stroma substance chiefly consisting of the posterior leaf) may appear darker and more bluish. Localized areas of atrophy, such as result, for example, from the resolution of nodules, may leave darker discolored spots; but with the optic section it will be seen that the stromal thickness is thinned out, leaving only a narrow padding of tissue over the posterior pigmented layer (Plate XLIX, fig. 7 ). In other words, owing to actual loss of stromal substance, an excavation occurs.

Immobilization of the sphincter by adhesions or by the organization of exudates, leads to its atrophy or disappearance, so that proximal illumination no longer brings out its ordinarily sharp peripheral border. Also, the pupillary edge, which may be sharp or fringed, can be drawn backward (i.e., towards the lens) together with the sphincter; this results in a slight degree of entropion (Plate XLIX, fig- 3) In cases of postinflammatory iris atrophy of long standing, ectropion of the posterior pigment layer can occur (Plate XL VIII, fig. 8 ). Evidently atrophy of the stroma, combined with traction of organized membranes over the iris surface, serves to evert and draw the pigment over the iris.

An interesting form of rapid tissue dissolution occurs in necrosis of iris (Samuels) This is the sequel to a sudden cutting off of the blood supply, e.g., by trauma, glaucoma, localized thrombosis, or tumors, or by an overwhelming toxemia generated in an acute or massive bacterial infection, especially following perforating wounds or in association with necrotic tumors. Histologically, necrosis differs from atrophy in that in the former, acute swelling with destruction of nuclei results in a ghostlike appearance of the tissue while in the latter, although the tissue becomes thin and condensed, it still retains some of its cellular aspects. Biomicroscopically, it may be impossible to differentiate between these two processes. Depending on the circumstances, one could surmise that many cases that are diagnosed as iris atrophy might have been the result of necrosis. In those cases in which so much of the iris tissue is destroyed that only a trans


PLATE LI


Fig. I. Diabetic rubeosis of the iris. Secondary glaucoma. Complicated cataract.

Fig. 2. Rubeosis iridis - glaucoma.

Fig. 3. Rubeosis iridis - chronic iritis.

Fig. 4. Rubeosis iridis glaucomatosa. Hyphemia. Following thrombosis of the central retinal vein.

Fig. j. Localized iris atrophy following glaucoma.

Fig. 6 . Secondary pigmentation of the iris (glaucoma) .

Fig. 7. Iris atrophy - rubeosis iridis. Secondary glaucoma. Vascularized exudative membrane over the lens capsule.

Fig. 8. Same case as Figure 7. The iris is viewed by optic section. Observe vaulting of iris below.


864




INFLAMMATION OF THE IRIS


867


parent veil remains (retro-illumination), one could perhaps be justified in speaking of iris necrosis rather than atrophy.

In postinflammatory as well as in other types of atrophy of the iris, visible vessels are present (Plates XLIX, figs. 3, 7; LI, figs, i, 2, 3, 4, 7, 8). For the most part these appear to be the ordinary trabecular vessels which have become permanently engorged. They have as a rule the characteristic radial direction, although as they approach the lesser circle, branchings may occur; then, meeting other divisions, the vessels may follow the direction of the lesser circle (Plate LI, fig. 2). From there more or less radial branches may extend to the sphincter area. With more extensive stromal atrophy new-formed vessels become manifest. They tend to be larger than the trabecular ones, have no sheathings (uncovered) and run irregularly not only within the stromal substance but also on the iris surface. In addition, they frequentl}'^ appear as convoluted tubules or even varices. With recurrence of an attack of iritis or even spontaneously, rupture of these vessels results in hyphema with its attendant complications (page 871).

In 1883 Fuchs demonstrated histologically that new-formed surface vessels may lie in an exudative membrane that covers the iris surface and frequently extends over the pupillary area (Plates XLIX, fig. 7; LI, figs. 7, 8). These vessels, instead of terminating or looping back at the pupillary margin, continue over it in the membrane which partly or completely covers the pupil. An organized exudative membrane of this kind, which extends over the pupillary margin, can result in seclusion; if it covers the pupil entirely, it may cause occlusion (Plate LI, fig. 7) . Unless a "circulation hole” remains, this will be followed by iris bombe and secondary glaucoma. Such pupillary membranes are commonly found after severe or chronic involvements, especially with the granulomatous infections, and may not only cover the surface of the iris wholly or in part but may also form on the posterior surface of the iris, causing complete or extensive adhesions. The presence of a surface membrane contributes to the discoloration of the iris (Plate LI, fig. 8 ) . Ectropion of the posterior retinal pigment layer can occur as a consequence


868


BIOMICROSCOPY OF THE EYE


of long standing iritis, especially in degenerated eyes after prolonged periods of increases of intra-ocular pressure. This sequel of events occurs frequently following absolute glaucoma, in cases of detachment of the retina, intra-ocular hemorrhages and tumors as well as from long-standing inflammations. Sclerosis of iris fibers together with traction of organizing exudate may be the causal factors in producing the eversion of the posterior iris pigment layer (see congenital ectropion, page 789). The degree of ectropion varies from case to case; collar-like, sectorial or apron-like forms may occur. The peripheral limits of the ectropion on the iris surface may be irregular, resulting in a zigzag dentate edge (Plate LI, fig. 4) .

As a terminal picture, seclusion of the pupil may lead to “vaulting” or folding of the iris (Plate LI, fig. 8). The aqueous trapped in the posterior chamber pushes the iris forward toward the cornea until the anterior chamber is practically abolished, except for a small area in the vicinity of the pupil. Extensive adhesions (synechiae) in sectors in which the whole posterior iris surface is bound down, i.e., from the pupillary area to the root of the iris, may prevent the iris from being pushed forward uniformly; thus the iris has a folded appearance. This naturally would prevent the formation of typical iris bombe.


21 Specific Types of Iritis

The protean biomicroscopic aspects exhibited by an endogenous iritis or iridocyclitis, even those consequent to the same cause, in itself should caution one against presuming an etiologic diagnosis on the basis of the ocular picture alone. For example, in gonorrhea, syphilis, or tuberculosis forms may occur which range from the socalled abortive type to simple, exudative, plastic, or proliferative types. Although clinically many of the so-called rheumatic iritides (e.g., those resulting from focal infection, possibly depending on the presence of local tissue allergy) , the gonorrheal, and luetic types of iritis tend to run an acute course, while others (e.g., the tuberculous type) are characterized by chronicity; but actual statistics assembled by numerous workers indicate a wide variability in the intensity of involvement. This is not unexpected when the pathology of the lesions is considered. Therefore, the clinical or biomicroscopic appearance must never be taken by itself as absolutely pathognomonic. In my experience, thorough medical survey all too frequently fails to reveal the source or nature of the infection in a considerable proportion of endogenous cases. In these we are forced to rely on any suggestive aid afforded by the clinical appearance. It is here that the biomicroscope may prove of incalculable value as will become evident from the consideration of some variations occurring in special types of iritis. For the purposes of orientation I include a classification (modified after Duke-Elder) of the various forms of exudative iritis, but I shall describe only those that are of special interest from the standpoint of biomicroscopy.

869


870


BIOMICROSCOPY OF THE EYE

I. Specific infections

A. Herpes

B. Gonorrhea

C. Syphilis

D. Tuberculosis

E. Brucellosis

F. Leprosy

G. Trypanosomiasis

11. Syndromes of doubtful etiology

A. Sympathetic ophthalmitis

B. Uveoparotitis

C. Boeck’s sarcoid

D. Heterochromic iridocyclitis

E. Uveitis with alopecia, vitiligo, poiliosis, and dysacusia (Vogt)

III. Fungus infection (mycoses)

A. Aspergillosis

B. Blastom^'^cosis

IV. Iritis and iridocyclitis due to irritants

A. Physical agents; chemical or burns

B. Nodosa


Herpetic Iritis

In most cases, whether due to herpes simplex or herpes zoster, the iritic irritation is attendant on a corneal or conjunctival lesion, i.e., a reaction secondary to the point of inoculation of the virus. This may cause an ordinary simple or exudative type of iritis having no distinctive features - in other words, the diagnosis will depend on the presence of conjunctival or corneal involvement with or without the associated skin lesions (zoster). Or, more rarely, specific eruptive lesions on the iris may occur. It is my impression that the latter is more common with herpes zoster than with herpes simplex. Such an iritic lesion, corresponding to that of the skin, appears as a small condensed area, slightly discolored, swollen, and surrounded by congeries of dilated veins. In a recent case, in which there were


SPECIFIC TYPES OF IRITIS


871


several lesions on the skin of the forehead above the involved highly inflamed, painful eye, there was a small lesion at the temporal corneal limbus. Extending from the lesser circle of the iris to the pupillary margin there was a small highly vascularized raised area. At the adjacent pupillary margin the iris margin was bound down to the lens capsule by a broad pigmented adhesion. The aqueous flare was marked, and there was a considerable number of keratic precipitates. After about six weeks the acute symptoms abated somewhat, but the e)e remained congested and photophobic for about three months. It was not possible to separate the adhesions by mydriatics. Six months after onset the eye became entirely quiet, leaving not onty a peripheral corneal scar involving the anterior corneal stroma but also a punched out circumscribed depigmented area in the iris with several threadlike vessels remaining in the neighborhood (Plate LII, fig. i). The characteristic vascular reaction in the iris, when it is intense, may lead to a hyphemia which is slow in absorbing (Plate LII, fig. 2 ). Lowenstein described a case of this type occurring in a 3 3 -)'-ear-old man who had five attacks within four years. Of these, four occurred in the right eye and one in the left eye. This case was characterized by violent, recurring attacks of a papular iritis associated with severe neuralgic pains limited to the affected side, and by intense ciliary injection; this was followed by anterior chamber hemorrhage each time. The pain always abated with the appearance of the hemorrhage. Examination of the right eye at the time of the last attack revealed an edematous cornea with two paracentral maculae. Three-fourths of the anterior chamber was filled with blood. After a paracentesis it was possible to obtain a better view of the iris. There were numerous swollen papular areas, in both the pupillary and ciliary zones, distributed irregularly over the surface of the greenish yellow iris. These swollen areas were covered with new-formed vessels, appearing as bright red spots. There were small stromal hemorrhages about these clusters of vessels. The pupil showed many synechiae, with pigment deposited on the anterior lens capsule. The iris as well as the posterior corneal surface were likewise


PLATE LII


Fig. I. Herpetic iritis. Optic section through localized lesion, showing loss of substance.

Fig. 2. Herpetic iritis with recurrent hyphemia. Iridectomy. Complicated cataract. (After Gilbert.)

Fig. 3. Chronic plastic iritis. Small gonococcal. (After Kruckmann.)

Fig. 4. Recurrent iritis. Old small adhesion nasally above, fresh exudate below. Iris atrophy (gonococcal).

Fig. 5. Roseolae of the iris (lues).

Fig. 6 . Papular iritis (lues) .


872



SPECIFIC TYPES OF IRITIS


875


Sprinkled with pigment. A dark hj'-phemia occupied the lower part of the anterior chamber.

In summarizing the findings in herpetic iritis, Gilbert mentions: (i) severe neuralgic pains, (2) circumscript swelling of the iris corresponding to the eruptions of the skin, (3) general pr localized hyperemia of the iris, especially within the lesser circle, and (4) single or recurrent hemorrhages in the anterior chamber, after which the pain decreases. In severe cases, with recurrent hemorrhages, blindness results after seclusion or occlusion of the pupil by the establishment of absolute glaucoma. According to Meller (1920) hemorrhages may be marked by a hypopyon. In milder cases the hemorrhages are absorbed quickl) and resolution with healing follows.


Gonococcal Iritis and Iridocyclitis

The exudative form of gonococcal iritis is of special interest to the biomicroscopist because of its characteristic appearance. According to Byers this form occurs in about 10 per cent of cases of gonorrheal iritis. The remainder are more or less equally divided between the simple and plastic forms (Plate LII, fig. 3 ) .

The acute exudative type is marked by a profuse elaboration of a jellylike fibrinous mass which at times may fill the entire anterior chamber and simulate, on hasty examination, an anteriorly dislocated lens (Fig. 324). Such a translucent gelatinous formation usually hides the pupil when first seen. Dilation, however, rapidly changes the picture, in that within the following few hours the exudate drops down to the bottom of the anterior chamber and the pupillary margins become visible. Evidently the exudate in the beginning is attached to the pupillary border. In other cases the mass

Personally I have not had the opportunity of examining biomicroscopically a case of the rarely occurring metastatic (endogenous) gonorrheal conjunctivitis associated with iritis. Zeeman (in Berens’ textbook) states: "It is characterized by bilateral hyperemia of the bulbar conjunctiva and episclera; the palpebral conjunctiva is congested at times, but always in a lesser degree than the other tissues. Discharge, if present, is scanty. It may develop into subacute epibulbar conjunctivitis with multiple vesicles or papules resembling phylctenules, and is frequently associated with vesicular keratitis or a slight infiltration of the corneal parenchyma. According to Byers (1908) 30 per cent of these cases show a diffuse opacity of the cornea, hyperemia of the iris, and opacity of the aqueous within the first few days. In fact all the signs of iritis are present.”


876


BIOMICROSCOPY OF THE EYE


may only partly fill the anterior chamber and tends to gravitate to its lower parts. This type of exudate forms rapidly and likewise tends to reabsorb speedily. I have seen cases in which the exudate formed and disappeared within forty-eight hours after the initial onset of the process.

In a recently observed case, about four days following its onset, in what appeared to be a simple iritis, the lower part of the pupil was suddenly occupied by a saggitally flattened-out gelatinous mass hanging suspended in the middle of the anterior chamber and, in the aqueous above it, cells and flocculent material were present. A week later the gelatinous material had absorbed and the iritis then ran an uncomplicated course for several weeks until clearing began. During this time the turbidity of the aqueous gradually became less. Keratic precipitates appeared and one permanent posterior synechia developed.

Another case occurred in a young man, aged 35 years. He had been under intermittent treatment for gonorrheal prostatitis for several years and had seven attacks of iritis during this time, four in the right eye and three in the left eye. In each eye the initial attack was typically exudative and cleared with no residua. The subsequent attacks, except the last in the right eye, were all simple and abortive, and lasted from a few days to a week with no permanent sequellae. However, the last attack in the right eye was plastic in nature and was more violent; it lasted several weeks. As a result a broad posterior iritis adhesion developed below (Plate LII, fig. 4) . This synechia became permanent and even resisted such sympathomimetic agents as epinephrine and neosynephrine. The posterior corneal surface and anterior lens capsule were dusted with precipitates. There were numerous pigmented deposits on the anterior vitreous trabeculae. The vision was reduced to 20/40.

Cases have been described in which excessive cellular exudation led to hypopyon and others in which extreme hyperemia of the iris was followed by actual hemorrhage into the anterior chamber with the formation of a hyphema. These are rare occurrences. With


SPECIFIC TYPES OF IRITIS


877


proper treatment recover)'- is the rule, although remissions are frequent, especiall)'^ if the original focus is not eliminated.

The plastic or proliferative variety also may start violently and because of the tendency for the formation of broad and multiple synechiae, dire results may ensue, owing to recurrences and extension of the inflammation to the ciliary body and vitreous. The proliferations are found as whitish bands attached to, and running concentric with, the pupillary edge - especially inferiorly. A considerable amount of plastic exudate may be found adherent to the anterior lens capsule even in the pupillary area (Plate LIT, fig. 3 ) ; this is seen as roundish or irregular thin, flattened, whitish plaques, some of which ma)'- be partially dusted with pigment. In the beginning numerous efflorescences may foreshadow adhesions. At times the pigment of the pupillary border is pulled off and after disintegration is scattered and deposited in the form of granules on the lens capsule, posterior corneal surface, or on the iris itself. Alternately, detached pigment may be seen in the form of ropes or strings attached to the capsule or to neighboring areas, along the pupillary margin itself. The proliferative action and fibrinous organization may result in eventual seclusion of the pupil with the attendant dangers of such a complication. Varying degrees of iris atrophy may follow depending on the severity and occurrence of remissions, although the tendency to form keratic precipitates is not a usual feature of gonorrheal iritis or iridocyclitis, successive attacks may nevertheless leave permanent fine keratic precipitates; in the extreme state their toxic effect and associated epithelial changes may cause some loss of corneal transparency. The picture of recurrent plastic gonorrheal iridocyclitis is one that in its chronic phases is clinically and biomicroscopically not specific and at times may closely resemble the exudative type of tuberculous iritis.

Syphilitic Iritis and Iridocyclitis

Although luetic involvement of the uveal tract may appear at any time following the general systemic invasion of the disease, predominantly, acute iritis or iridocyclitis occurs in the so-called secondary


878


BIOMICROSCOPY OF THE EYE


stage (early or recurrent), usually in association with the skin rash and mucous patches, or as a late manifestation during the tertiary stage. The wide variations of its incidence, as reported statistically in the literature, is probably related to differences in locale with differences in racial factors, institution of early therapy and variability in natural individual resistance.! From the standpoint of the biomicroscopic appearances all manner of variations may be found, from the early and late roseola of the iris to the marked and plastic exudative, papular, or nodular iritis. Consequently unless we meet, for example, a typical case of iritis papulosa, a specific diagnosis, by biomicroscopic means alone, may be difficult or impossible. As a general statement, luetic involvement of the iris tends to run an acute course rather than a chronic one, so characteristic of tuberculosis. Healing is usually rapid and frequently occurs with no or little sequelae, especially if treatment is instituted early.

As a matter of fact, owing to modern methods of diagnosis and especially to the rapidity and thoroughness with which treatment is applied in the early stages of infection, luetic involvement of the iris is not as common as in the past. Iritis papulosa or gumma, for instance, described frequently in the last century, are now comparatively rare.

Koseolae, which may be the first indication of systemic luetic infection, are the result of localized areas of hyperemia (Plate LII, fig. 5 ) . Macroscopically, they appear as small irregular red spots, resembling petechial hemorrhages, but with the biomicroscope they are seen to be composed of congeries of superficial dilated vessels, probably venules or capillaries of the superficial leaf. Because of the presence of the obscuring surface pigment in brown irides, roseolae

Acute iritis may also be initiated as the result of a Jarisch-Herxheimer reaction and, rarely, as a recidive reaction following inadequate therapy.

t For example, Igersheimer^® found 28 per cent of cases of acute iritis and 8 per cent of chronic iridocyclitis in syphilitics. From 6 to 70 per cent of all cases of iritis are said by various authors to be luetic. In summing up the subject of syphilitic iritis J. E. Moore styes; "Whether early or late, iritis is twice as common in colored patients as in white patients with syphilis and slightly more frequent in males than in females; iritis may be expected to occur in from 4 to 5 per cent of all patients with early secondary syphilis. It is almost twice as frequent as a manifestation of a recurrent secondary syphilis, and is a fairly common manifestation of late syphilis.”


SPECIFIC TYPES OF IRITIS


879


are seen chiefly in blue or lightl)^ colored irides and in these they are confined chiefly to the region of the lesser circle and ciliary zone. Deep roseolae. probably occur but because of the overlying tissue are not readily visible.

Roseola iridis is an early and transient vascular manifestation, coincident with the appearance of the macular rash and mucous patches, lasting a few da^'^s and disappearing without other manifestations of iritic irritation or exudation. However, in one case that I saw, faint anterior chamber flare was present. The exact mechanism which leads to the formation of roseolae is not known. Kruckman believed that roseolae represent a mild tissue reaction to minor capillary emboli,*'^^® but pathologically, the changes in the primary or secondary stages of lues are not the result of vascular involvement as originally proposed b)’^ v. Michel (1881)."“*'^ In these stages, vessel involvement, if present, is probably secondary to changes occurring in the periadventiteous connective tissue (the primary location of the inflammation) either by mechanical pressure or by extension. Experimentally, in animals Igersheimer found that vessel changes may be absent.

It is questionable whether it is proper to consider the local hyperemic areas, which occur somewhat later (up to the second year after infection) and which are associated with frank iritis, as recurrent roseolae. These lesions are more definitely part of an inflammatory and exudative reaction, and probably should more properly be called "iritis papulosa.”

Savati Kowa (1927) examined a case biomicroscopically in which roseolae were found in the pupillary zone. They were situated all around the iris circumference and seemed to lie on the surface. The vessels resembled short curved rods - snakelike - with apparently blind-ending branches. Following treatment the roseolae disappeared within a few weeks. During the entire visible "life cycle” of the roseolae, there was only a minimal or faint pericorneal blush.

In a case that I had occasion to follow, in one sector the appearance of the roseolae was preceded by two radially directed vessels, running from the periphery to the lesser circle. These vessels ran


880


BIOMICROSCOPY OF THE EYE


between and parallel to the iris trabeculae and, within 24 hours, at their termination in the region of the lesser circle, small roseolae formed. However, in other sectors no radial vessels .were seen although there were well-formed roseolae present. Since roseolae are not accompanied by any subjective symptoms or complaints, e.g., such as pain, photophobia, tearing, or visual disturbances, it is usually only by chance that a case presents itself to the ophthalmologist.

The acute exudative and plastic forms of iritis which occur predominantly during the secondary stage (either concomitantly with the rash or, rarely, before) may also appear during the tertiary stage of the infection. Unless well-formed papules appear, those of luetic etiology may be clinically indistinguishable from the acute plastic iritis resulting from other causes. When severe, which is commonly the case, luetic keratitis is characterized by a profuse fibrinous exudation. The aqueous may be very turbid, disclosing filiform structures or even a larger gelatinous exudate in association with large, dirty gray keratic precipitates. The iris, itself, is diffusely swollen and, if lightly colored, shows hyperemic vessels arranged radially or in the form of starlike roseolae. A thin coat of fibrin may cover the iris surface. Biomicroscopically, tissue condensation within the stroma or visible elevated papules may be present.

The tendency to form synechiae is marked. These may be broad and accompanied by flat grayish exudates on the anterior lens capsule. At the height of the process the cornea usually becomes hazy not only from the presence of precipitates but also from edema of its parenchyma and epithelium. Ordinarily, the prognosis is good, especially if local and systemic treatment is instituted.

The term "iritis papulosa” is used to designate that form of acute exudative syphilitic iritis, in which elevated well-defined evanescent papules appear on the iris surface, visible by gross methods of examination (Plate LII, fig. 6 ). Statistics concerning the incidence of these papules in syphilitic iritis vary greatly. For instance, Groenouw noted them in 8.85 per cent of his cases, Ozapodwasky in 23 per cent, Igersheimer in 40 per cent, and more lately Moore in only 6 per cent (secondary and tertiary) . It should be noted that


SPECIFIC TYPES OF IRITIS


881


these estimates were made for the most part without benefit of the biomicroscope. If we take into account the deeper nodular condensations within the iris stroma, which can only be properly seen with the biomicroscope (especially in the lighter colored irides) , I feel that a much higher percentage would be noted.

Histologically, since the early investigation of v. Michel ( 1 8 8 1 ) who believed that the process started within the vessels, until that of Igersheimer (1518)^®^ and others, even more recently, the tendency for the infiltrations in the uveal tract to form nodules was clearly evidenced. These nodules, which consisted of condensations of infiltrating lymphocytes and plasma cells, also contained typical giant cells but were devoid of caseation. Deep nodular formations situated in the pupillar)^ region may erode through the posterior iris surface and cause extensive posterior synechiae.

Iritis papulosa may usher in the manifestation of the secondary stage of syphilis, although Moore (1931)^^® found it several times in a series of 109 cases of tertiary iritis. In the secondary stage it is usually accompanied by skin and mucous membrane lesions. As Zeeman has aptly stated in Berens’ textbook, "As a rule, a glance at the patient’s back or throat settles the diagnosis.” Typically during the early stages of iritis, small round or pyramidal (Kruckmann) shaped nodules project themselves from the iris surface chiefly in the vicinity of the pupillary and ciliary margins f (Plate LIII, figs. 1-5). They vary in size from a pinpoint to 4 or 5 mm., or more. Some are solid in appearance while others look like empty cysts. Recently I had occasion to observe a case occurring in a young Negress. Coincident with a follicular-papular rash of the skin of the trunk, an acute iritis developed simultaneously in both eyes. Over the surfaces of the irides many translucent globular cysts were

Gummas of the iris are rare and usually invade the iris by extension from the ciliary body. The essential difference between papules and gummas is evidently one of degree or intensity of involvement rather than one of fundamental structure. The resulting picture of syphilomatous infiltration (papules and gumma) is (i) formation of small papulous nodules with little tissue destruction, which heal with minimal atrophy or scarring, (2) larger nodular-like formation with extensive central ulceration (gumma and scar tissue formation), and (3) a formation, in which the process of regeneration predominates over the tendency of scar tissue.

t In about 50 per cent of cases the affection is bilateral, but both e5'es may not be involved simultaneously.


PLATE LIII


Fig. I. Papules in luetic iritis. (After Kruckmann.)

Fig. 2. Atrophic spots resulting from healed papules. (After Kruckmann.)

Fig. 3. Group of syphilitic lesions (eight months after initial lesion). Several papules and one vesicle. (After Kruckmann.)

Fig. 4. Papules, luetic iritis. Keratic precipitates.

Fig. j. Verruca-like growth with internal hemorrhage following luetic nodular iritis. (After Kruckmann.)

Fig. 6. So-called "iris condyloma” in a woman appearing six years after initial infection.


882



SPECIFIC TYPES OF IRITIS


885


seen forty-eight hours after the onset of the attack (Plate XL VII, fig. 5 ) . Within a few days granules of pigment were found on these cysts. Small keratic precipitates and several posterior synechiae developed; the latter later were separated by atropinization. These floccular structures remained for about a week and then disappeared. Vigorous antiluetic therapy was begun and in about 3 weeks the lesions in both eyes quieted down; the only residua were several small pigmented keratic precipitates and pigment clumps on the anterior lens capsule.

Tuberculous Iritis and Iridocyclitis

Since the end of the last century, tuberculous uveitis has excited the interest of ophthalmologists. With each advance in our knowledge of this condition, controversial "schools” of thought developed. Even today, in spite of the accumulated mass of clinical and experimental data, we still are forced in most instances to make the diagnosis of the presence of a tuberculous process by inference or by exclusion. In the majority of cases of endogenous uveitis, in which a tuberculous etiology is suspected, it is not always possible to recognize clinically the presence of the pathognomonic tubercle. There is no question, however, that with the aid of the biomicroscope one becomes increasingly aware of indicative iritis changes, but one must not forget that frank iritic nodules or condensations of iris tissue occur in infections of other etiologies. In many of these we can be aided by other diagnostic methods, e.g., the serology tests for syphilis, the Frei test for lymphogranuloma venereum, the agglutination test for brucellosis, etc. In certain cases of low-grade chronic tuberculous cyclitis, the iris may appear entirely normal or may show only an occasional ectodermic nodule of the pupillary margin until secondary complications (increased intra-ocular pressure or extension and progression anteriorly or posteriorly) become evident. In the early stages of this type of involvement, an aqueous flare, keratic precipitates or vitreous opacities, with or without slight ciliary injection, may be the only findings.

Excluding the forms in which clinically it is possible to make a


886


BIOMICROSCOPY OF THE EYE

definite diagnosis (e.g., lues), European observers consider that tuberculosis is the chief cause of endogenous iridocyclitis, particularly the chronic type. Whether or not such a conclusion is valid, only time will prove. Already we know of forms caused by conditions which simulate the picture of tuberculosis (e.g., brucellosis and Boeck’s sarcoid) and which heretofore were often considered of tuberculous etiology. Likewise there is still controversy concerning the mode of infection in tuberculous uveitis. The thesis that the uveal tract can be infected in a primary manner was developed because of the fact that tuberculous uveitis commonly occurs in apparently healthy persons with no signs of active tuberculosis; but this is no longer favored. In selected groups microscopic evidence of healed tuberculous lesions of other organs has been found on postmortem examination in from 42 per cent (Whitehead, 1922) to 90 per cent (Wehlinger and Blangey 1933-1934). Since these patients died from other causes, it must be assumed that they overcame the original tuberculous infection. Considering the universality of the finding of healed or quiescent tuberculous lesions mediastinal (hilar) and mesenteric lymph nodes and localized lesions in the pleura and internal organs, it is remarkable how little tendency there is for the infection to spread. Evidently other factors must come into play. Excluding the rare acute miliary form, in which a fatal massive generalized infection occurs, it is probable that ordinarily the uveal tract becomes involved via the blood stream, following "a mild transient bacillemia.”

On the other hand, as has been shown experimentally in animals, the degree of ocular involvement not only depends on the “violence and massiveness of the infection” but also on the immunologic state of the animals.'* Hence two main groups of reactions appear pos Duke-Elder, summarizing the experimental findings of many M'orkers,*”® states: "If the animal has not been previously infected, tubercle bacilli reaching the eye produce a slowly progressive ocular tuberculosis with tubercle formation. Depending on the quantity of bacilli reaching the eye, these may be miliary or few; and depending on the virulence of the bacilli may ultimately result in caseation and perforation of the globe. If on the other hand, the animal has been previously infected, quite a different picture results from a second infection either with living or dead bacilli or even with tuberculo-protein an acute caseating lesion appears which is quite noncharacteristic of tubercle which in some cases is selflimited and heals, usually with subsequent recurrences, and in others, depending on the number and virulence of the bacilli and the resistance of the animal, progresses with an intense caseating reaction which leads to perforation.”


SPECIFIC TYPES OF IRITIS


887


sible: (i) the reaction to an original infection and (2) the reaction occurring in one already sensitized from a previous infection. In both instances, the severity of involvement will depend on the resistance of the patient as well as the massiveness of the infection. In the first group, if the patient’s resistance is very low, acute miliary lesions may result, but if it is high, typical discrete or confluent tubercles (chronic tuberculous lesions) appear which may become progressive (destructive and diffuse) or nonprogressive (relatively benign) ; that is, the lesions may be typically “productive” or proliferative. The acute massive (caseating) tuberculous iritis and the acute disseminated iritis occurs in the very young and as a rule spreads to the deeper structures and results in loss of the eye. In the second group, two varieties of tuberculo-allergic reactions may appear - a chronic and recurrent exudative form or, rarely, an acute plastic form. The latter tends to affect those in early adult life while the former occurs during the fourth decade.

Although such sharp divisions, based on experimental work, may be valid for the purposes of understanding the pathogenesis of uveal tuberculosis or for establishing a working classification, clinically it is possible and probably more usual to see one form merge into another or to find simultaneous manifestations of both in the same eye. For example, in tuberculous iridocyclitis it is not uncommon to find the proliferative type of lesion (tubercle) in an iris that is also undergoing an acute plastic or a chronic exudative type of involvement. As previously mentioned, this will become more evident after such cases are carefully studied with the biomicroscope. Such confused or mixed pictures undoubtedly result from variances not only in the virulence of the organisms and their toxins but also in the patient’s natural general resistance or local tissue resistance. In the same way the strict division into acute and chronic forms is only arbitrary, since even the so-called chronic variety may be initiated or punctuated by “acute” attacks or b}'- exacerbations. Vogt, who believes that tuberculosis is the chief cause of most of the subacute or chronic endogenous anterior uveitidis, makes out a strong case for the influence that is played by heredity in the sense of an increased susceptibility. However, all persons with an inherited suscept


888


BIOMICROSCOPY OF THE EYE


ibility do not develop tuberculosis unless their resistance is lowered by exposure, poor nutrition, or poor hygienic living conditions. It would appear that this inherited susceptibility may have a predilection for certain organs (organotropism) or even certain cell groups; therefore, it is possible that an inferiority or susceptibility to tuberculosis may be transmitted by independent genetic factors not only to the whole organism but also to a specific organ or to particular parts of an organ. In order to prove that hereditary inferiority is a decisive factor in the localization of tuberculosis to even special parts of the eye, Vogt brought an impressive array of cases in which tuberculous keratitis or iridocyclitis was found in father and son, mother and daughter, aunt and niece, and in sisters. Wehlinger and Kiinsch have shown in a study of tuberculosis in identical and dissimilar twins and that the former (provided one of the twins is affected) is twenty times more liable to acquire tuberculosis than are the latter.

Morphologically and from the standpoint of biomicroscopy two main t5^pes appear: (i) the proliferative and (2) the exudative. In both types the process may be ushered in by an acute phase or it may start benignly with little outward inflammatory reaction and develop chronically. Also in both the ultimate outcome varies (depending on the violence of the infection and resistance of the patient) from complete resolution to degrees of damage that may result in partial or complete destruction of the eye. In the earlier literature, only the rare proliferative types were recognized, since these were characterized b} the frank appearance of nodules (tuberculomas), either discrete or conglomerate, or the rapidly progressive and devastating diffuse proliferating types (also rare), in which a violent caseating and necrotizing lesion soon destroyed the entire globe. As previously mentioned, examination with the biomicroscope more and more brings to light mixed types, i.e., combined forms of the proliferative and exudative types or those which in time may merge from one type into the other.

Vrolijerafive Types. The proliferative types are characterized by tubercle formation - a nonspecific defensive response of tissue


SPECIFIC TYPES OF IRITIS


889


against the noxious agent (nodules are produced in other conditions besides tuberculosis) Depending on the resistance of the host, two processes occur within tubercles: "the one caseation - distinctive and dangerous, and the other sclerosis - conservative and healing.” In tubercles of the iris both these processes occur but fortunately the severe caseating variety (e.g., diffuse proliferative tuberculosis and the destructive conglomerate tubercle involving iris, ciliary body, or choroid) are rare. These more malignant types, which tend to destroy the eye, are more common in the young. Cases have been reported in young persons in whom an acute caseating ocular tuberculosis was followed by a general body dissemination with fatal termination. In adults with higher resistance the appearance of a tuberculous nodule in the iris may occur with little or no reaction (slight or absent anterior chamber flare) and with or without any ciliary blush. Permanent and complete healing can follow, or alternately, in consequence of tissue sensitization, acute exacerbative exudative reactions may complicate the picture and lead to severe sequelae.

For the purposes of classification f the proliferative types of tuberculous iridocyclitis have been divided into:

I. Acute miliary lesions

II. Chronic tuberculomatous lesions

A. Benign lesions (single or multiple tubercles)

B. Slowly progressive conglomerate tubercles (ultimately destructive)

C. Rapidly progressive and destructive lesions - diffuse proliferative tuberculosis

ACUTE MILIARY LESIONS

Acute miliary tuberculosis is generally a fatal disease, in which massive and overwhelming doses of bacilli, injected into the vascular system, are widely disseminated throughout the organs. As a result

For example, syphilis, sympathetic ophthalmitis, leprosy, and as a foreign body reaction in iritis nodosa and neoplasms. Since most of these conditions can be ruled out by other methods, the frank appearance of nodules should at least be considered suspicious of tuberculosis.

t Modified after Duke-Elder.


PLATE LIV


Fig. I. Tuberculous iritis. Efflorescences and one nodule at 3 o’clock.

Fig. 2. Tuberculous iritis in a child.

Fig. 3. Abortive nodules in the case of tuberculous iritis.

Fig. 4. Miliary tubercles and exudation in a 21-year-old man.

Fig. j. Tuberculosis of the iris. The nodules and floccules are seen in various stages of development. Note large intrastromal nodule at lesser circle.

Fig. 6 . Exudative iritis with numerous superficial floccules.


890



SPECIFIC TYPES OF IRITIS


893


the involved tissues become "shot through” with tubercles. The uveal tract, particularly the choroid, may share in the generalized metastatic involvement but clinically they have not been noticed during life as frequently as necropsy data would indicate (Plate LIV, figs. 2, 4) . In acute miliary tuberculosis, the clinical presence of iris tubercles is a great rarity. The fact that they have been seen so seldom may possibly be explained by their deep location within the stroma itself. As von Michel pointed out (before the days of biomicroscopy) only superficial nodules that either elevate the anterior iris layers or project themselves from the iris surface can be grossly seen as such. Superficially-placed nodules can be seen even when they are still very small. They appear as grayish-yellow nodules, avascular and irregular, distributed over the iris surface. The more deeply situated nodules need not elevate the anterior surface of the iris but may push back the pigment epithelium layer. If not obscured by iris edema, aqueous flare, or keratic deposits the use of the narrow beam may reveal deeper condensations (tubercles) within the iris stroma.

CHRONIC TUBERCULOMATOUS LESIONS OF THE IRIS

Benign lesions (single or multiple tubercles) . In distinction to the acute miliary type, a more chronic and relatively benign form of tubercle may develop in the iris. It can occur in a quiet iritis with no ciliary injection and can be so ephemeral in character as to disappear within a week or it may be part of an insidious iridocyclitis. In more serious cases it may be preceded or accompanied by a mixed form of exudative iritis of varying severity. Rarely, as an extreme picture, confluence of the lesions may ultimately resolve into a devastating conglomerate tubercle. As already mentioned on page 830, iris nodules, efflorescences, and flocculi vary in size, location, and texture. First, there are the ephemeral efflorescences at the pupillary border, which are soft, pure white in color, and attached by a small base to the intact pupillary pigment border. (See Plate

Frequently, the appearances of nodules may be preceded by an acute iritis of varying severity.


894


BIOMICROSCOPY OF THE EYE


XL VII, fig. 4.) Second, there are the more solid mushroom-like nodules situated at the pupillary border (Plate LIV, figs. 1,3). When these arise from behind the seam they lie on the anterior lens capsule and tend to form adhesions. With mydriasis they can frequently be separated, leaving behind pigment and exudative spots, attached to the anterior lens capsule. The surface of these nodules is granular, owing to the adherence of pigment granules and cellular exudate. Third, there are superficial efflorescences and nodules of the mesodermal iris layer (Vogt, type I) . These are not a part of the iris substance but rather are attached to, and lie on, the surface. Vogt considers these as typical tuberculides. They are either more or less solidly homogeneous and opaque appearing bodies (nodules), which are best seen in light colored irides, or may resemble large glasslike efflorescences (floccules of Busacca) (Fig. 330). These structures are in themselves avascular and contain no iris tissue strands. Fourth, there are deep nodules within the stroma (Vogt, type II) . These are seen as waxy exposed homogeneous nodes, pushing the iris fibers aside, as localized surface prominences covered by superficial iris stroma, or as diffuse protuberant areas of glassy thickenings (Plate LIV, figs. 4, 5 ) . The latter, when in the neighborhood of the frill, may be easily overlooked; they are most easily detected in light colored irides. Iris vessels, if present, tend to run between or over nodules rather than into them.

SJotvIy progressive conglomerate tubercles. When nodules, such as described above as type II, proliferate and grow, confluence with neighboring nodules will result in voluminous masses (conglomerate tubercle) , which project forward into the anterior chamber and may or may not eventually reach the posterior corneal surface. The regions of the sphincter and peripheral ciliary zone are the common places of predilection. It is possible, even after the formation of large conglomerate protruding masses, for resolution to occur with varying degrees of iris atrophy as a residual finding. On the other hand, progressive growth and extension serves to spread the disease to contiguous parts. In the periphery such formations may cause anterior synechiae by drawing the iris forward or may occlude the


SPECIFIC TYPES OF IRITIS


895


anterior chamber angle. Such granulomatous masses, extending forward from the iris, may be nodulated or solid. They vary from a dirty gray or yellow to pink in color and could be compared with leucosarcoma; vessels may arborize over them but rarely invade the growths themselves. This picture becomes readily evident on employing the optic section. Nodular masses at the root of the iris may result from extension of a progressive conglomerate tubercle of the ciliary body. Invasion of the sclera via the drainage system (spaces of Fontana and Schlemm’s canal) is evidenced by a scleroperikeratitis (sclerosing keratitis) . The surface of the iris may also be inoculated from conglomerate tubercles of the ciliary body by the implantation of tuberculous material. Loosened particles from the inner surface of the ciliary body carried by the fluid currents become attached to the iris. Corneal affection may result from direct contact with masses in the anterior chamber or after perforation of the sclera. Tuberculous granulations, spreading over the cornea, cause a tuberculous keratic ulcer, which may result in perforation. Although the ciliary body tends to block posterior extension, deeper involvement via the pupil has been reported. With the formation of exudate, the pupil may be secluded and occluded. Extension to the lens may result in spontaneous rupture of the lens capsule and its involvement (described histologically by Mayou in 1903®^®).

The rapidly progressive and destructive form of diffuse proliferative tuberculosis is fortunately a rare occurrence. It is characterized by a highly toxic and necrotizing reaction which destroys all the ocular tissues. The eye becomes acutely inflamed and painful. The iris is thickened and heavy masses of exudate fill the anterior chamber. Posterior extension produces a picture similar to that seen in purulent panophthalmitis.

PLASTIC AND EXUDATIVE TUBERCULOUS IRIDOCYCLITIS

A tuberculous etiology for a nondescript plastic or exudative iritis or irodocyclitis of tuberculous origin can in most cases be inferred only by exclusion of all other etiologic factors. In a limited number of such eyes, tuberculosis has been demonstrated histologically. Mild


896


BIOMICROSCOPY OF THE EYE


and self-limited cases of iritis and iridocyclitis do not come to autopsy, and even in the more severe ones, in which complications necessitate removal of the eye, one should never make a positive clinical diagnosis without reservation. Among the features in the clinical aspects of a case which should be considered in this connection are (i) an insidious onset, (2) prolonged duration with a tendency to exacerbations, (3) the amount and character of the exudate (especially the keratic precipitates and the exudate on the anterior lens capsule), (4) the appearance (especially late) of localized condensations within the stroma, and ( 5 ) the degree of destruction in the iris itself.

The fact that tubercle formation occurs in the iris after the onset of a plastic or exudative iridocyclitis is well known to those who have carefully studied and followed these cases biomicroscopically. Whether nodules or nodular swellings on or in the iris indicate true tubercles is still unknown. As Vogt suggests (he examined such lesions histologically in one case ) , they may represent the tuberculid in the sense of Darier.

Both the acnfe plastic or the subacute or chronic types of iridocyclitis may start as a simple endogenous inflammation i.e., with an anterior chamber flare and slight ciliary injection. In the plastic type, within a few days this progresses into a highly inflammatory process, characterized by marked ciliary injection, pain, and considerable blurring of vision. Efflorescences at the pigmented pupillary border or seam presage the formation of posterior synechiae. The turbid aqueous frequently reveals the presence of larger flocculated material as well as dotlike cells. Keratic precipitates and varying degrees of edema of the corneal epithelium and stroma will be noted. The sudden appearance of a deep infiltration in the region of the limbus (sclerosing keratitis), which sometimes occurs, is in my opinion a diagnostic sign of great importance and, after ruling out other granulomatous infections, probably pathognomonic of tuberculosis.

The visibility of iris vessels (particularly the radiating ones) is most pronounced in light colored irides. Typical nodules (charac


SPECIFIC TYPES OF IRITIS


897


teristic of the proliferative forms) are not seen as a rule. Because of the nonspecific character of plastic iridocyclitis, it usually is impossible to make a definite etiologic diagnosis by the clinical picture


Fig. 333. Chronic type of tuberculous exudative and productive (combined form) iridocyclitis. (After Vogt.) Note exudative membranes at pupillary margin and tubercles on anterior lens capsule.

alone, especially in the initial attack. Recurrences may, however, result in pictures that resemble the chronic exudative or relapsing form, ordinarily seen in older individuals.

The chronic types of exudative iridocyclitis, which start more insidiously and are characteristically relapsing, are clinically more suggestive of a tuberculous origin. They may be ushered in with little, if any, ciliary injection but are soon followed by a progressive and relentless exudative process. As a result, the posterior surface of the cornea becomes studded with large precipitates of the "muttonfat” type. Broad and multiple synechiae may eventually lead to occlusion of the pupil. Flat exudative membranes may extend over the anterior lens capsule (Fig. 333). These at times actually pull


898


BIOMICROSCOPY OF THE EYE


stromal tags over the obscured or missing seam. These tags (dentate in type) become firmly attached to an exudative membrane on the lens capsule. The iris, which rapidly becomes atrophic, changes in color and results in the well known "sick-eye” appearance. It is in these cases that the biomicroscope will reveal the atypical nodular swellings mentioned above. Cellular infiltration in the vitreous usually occurs early but this together with the lens changes soon obscure any view of the fundus. Such a process may quiet down at any stage or may ultimately lead to loss of the eye.

Tuberculous Cyclitis. As indicated before, every iritis is probably associated with reaction in the ciliary body. Especially in the more severe forms, the exudative and proliferative changes within the ciliary body contribute in a large measure not only to the severity of the process but also to the ultimate fate of the eye. In the fulminating forms involvement of the iris masks the process occurring in the ciliary body; although direct inspection is impossible, involvement of the latter may safely be assumed. This of course has been borne out by histologic study and even clinically by evidences of complications, e.g., changes in intra-ocular pressure and vitreous opacities. Conversely, lesions which start as a primary focus in the ciliary body (page 808), may, by forward extension, involve the iris. Perhaps the most common form of cyclitis is the one that begins quietly with few signs of inflammation and that subjectively causes only a slight blurring of vision. Biomicroscopic examination at this time reveals only a faint flare in the aqueous and the so-called "mutton-fat” keratic precipitates. Such a reaction may remain minimal and with reabsorption leave no trace. I had occasion to see such a case in the left eye of a colleague, aged 37, who had one recurrence in 3 years. Each time a slight blurring of vision and a degree of tenderness to palpation were noticed. There was no definite ciliary injection at any time, and the highest intra-ocular tension recorded during both phases was 28 mm. Hg (Schiotz). The attacks of blurring, which lasted about a week in each instance, were associated with definite flare in the aqueous and with several discrete large "mutton-fat” keratic precipitates. A few white cells were seen in


SPECIFIC TYPES OF IRITIS


899


the anterior parts of the vitreous. There was no visible hyperemia of the iris or efflorescences at the pupillary margin. Examination one month after the last flareup revealed complete resorption of the precipitates. The fundus was entirely normal. An extensive medical survey gave negative findings, except for the radiographic diagnosis of an old healed pulmonary lesion.'*' This case illustrates a form of "quiet” tuberculous cyclitis which, without the aid of the biomicroscope, might easily have been overlooked. In others, the symptoms may be more marked and progressive, e.g., efflorescences of the pupillary margin with or without synechiae, hyperemia of the iris, a more pronounced infiltration in the vitreous, and increased intraocular tension. Secondary glaucoma is a formidable complication, which in the end may destroy the eye.

Leprosy of the Iris

Barros f in his excellent monograph has classified the iritis of leprosy clinically as follows: (i) Diffuse acute, subacute or chronic form, serous or serofibrinous; (2) localized form: miliary or nodular leprosy.

Acute Diffuse Iritis. Acute diffuse iritis of leprosy presents a fulminating serous or serofibrinous type of iritis characterized subjectively by pain, blurring of vision, photophobia, lacrimation, and blepharospasm. Only rarely are both eyes involved simultaneously. Occasionally it develops by extension from an episcleral lesion, § i.e., close to the limbus. Objectively the findings differ little from the acute violent iritis resulting from other causes. Ciliary injection is marked; corneal edema, bedewing, and keratic precipitates are present. In the aqueous the changes, depending on the amount and character of the exudate, vary from a simple Tyndall flare in the beginning to the formation of a large coagulum, not unlike that seen in gonorrheal iritis. In addition to the larger coagula, numerous threads may be seen,[| which at times may assume a cobweb form.

This patient’s mother had died of tuberculosis at the age of 29. t Barros, from the standpoint of biomicroscopy, has written the first authoritative description of ocular leprosy, "Some Clinical Aspects of the Ocular Involvement in Lepers."

J The term "nodule” is used in the morphologic sense rather than in the true histologic one.

§ See Volume I, pages 219 and 515.

II See Volume I, Plate XL, fig. 3.


900


BIOMICROSCOPy OF THE EYE


At the height of the inflammatory process there may be an increase in intra-ocular tension. Synechiae are common and often intractable (Fig- 334) • Barros only observed the presence of a hyphema on two


Fig. 334. Acute diffuse iritis of leprosy. (After Barros.)

occasions but hypopyon-like masses are frequently observed in the bottom of the anterior chamber. These at times may be somewhat obscured by an abnormally relucent limbal spur. As is the case with all types of acute fulminating iritides all manner of complications and sequelae may result: iris atrophy with generalized or localized areas of depigmentation, seclusio pupillae, secondary glaucoma and in the extreme cases, phthisis bulbi.

Subacute or Chronic Diffuse Iritis. The reaction in some of these cases may be so mild as to be distinguishable only by the biomicroscope. Subjectively the visible congestion may be absent or minimal and the principle symptom, if elicited, may be varying degrees of blurred vision, secondary to corneal edema and aqueous flare. In these cases both eyes may be involved simultaneously. The flare (exudation in the anterior chamber) may be present for long periods and there is less tendency to the formation of synechiae as compared with the acute type. In some the keratic deposits may be fine, but


SPECIFIC TYPES OF IRITIS


901


at times in others the larger mutton-fat type of deposit may be found. The exudate accumulated in the angle may become organized. The accumulation of any considerable amount of exudate on the posterior corneal surface exerts a toxic effect and frequently is followed by a secondary keratitis. Exudations of this kind at the pupillary margin may, after dilation and rupture of a synechia, leave a mass of pigment or a grayish nodular mass on the anterior capsule of the lens. Barros also described two cases in which trauma initiated a subacute attack of iritis in lepers. In both these cases the iris was covered with pearllike nodules (combined form). The fact that trauma may bring on an attack of leprous iritis is reminiscent of similar episodes in cases of hereditary lues in which ocular trauma may cause an acute attack of interstitial kerato-iritis.

Miliary and Nodular Iritis of Leprosy, This type is signaled by the appearance of numerous pearllike structures, commonly situated in the deeper iris layer between the frill and the pupillary border, in other words in the sphincter region. These efflorescences or pearls are best seen in light colored irides by indirect illumination. Often there may be a complete absence of iritic irritation or inflammation (no flare) . The granulations may be present for years with no acute symptoms. Hence, Barros states that “the eyes have a good tolerance to them.” Generally the condition is found to exist bilaterally with no interference with vision, although the pupillary reaction may be sluggish and dilation diflEcult. If not fully developed, the presence of these nodules may be overlooked unless indirect illumination with an overloaded lamp, and high power of magnification (6o X or more) are employed. When numerous, Barros has described their appearance as like a necklace surrounding the pupil (Fig. 335). They also may fill the crypts and later on may be found in the whole iris. In some cases with nodules of the deep mesodermal layer, transpupillary retro-illumination of the iris may reveal holes of the posterior retinal iris layer. Barros stressed the point that these nodules must be differentiated from the more whitish and superficial "pearls” of exudate seen in the diffuse serofibrinous forms. These may also be found in the pupillary area and may develop into large


902


BIOMICROSCOPY OF THE EYE

irregular cauliflower masses. The latter are superficially placed on the iris surface while the miliary "pearls” are located within the iris tliickness. In the early stages they can only be seen by indirect


illumination but later are visible by direct focal light after they become larger and more superficially placed. Barros states that he was unable, even after years, ever to see the transformation of these miliary lesions into the more conspicuous lepromatous nodule, although this should not be impossible since the latter is considered to be a miliary leproma.

As regards nodular leprosy of the iris, Barros in his large series only observed it in one case; in which in the right eye a large mass in the iris tissue extended from the iris root at 9 o’clock gradually decreasing in size to the pupillary margin. There was considerable exudation in the aqueous and a large keratic precipitate extending near the limbus from 9 to 6 o’clock.

It should be pointed out that both exudative diffuse iritis and miliary nodules may at times be found simultaneously or consecutively in the same eye.


Heterochromic Iridocyclitis

In this section only that form of complicated heterochromia, which is commonly designated the "heterochromic syndrome of Fuchs,” will be considered. The so-called simple hereditary type of heterochromia has previously been mentioned in the chapter on iris coloration (page 768 ). Likewise color changes resulting from atrophic states of the iris following senility and inflammations, glaucoma (vitiligo), etc., which some writers consider heterochromia, have also been discussed. The rarer so-called "neurogenic form,” secondary to a sympathetic lesion, presents nothing of special biomicroscopic interest (although Herrenschwand claimed that in this type he noted no atrophic changes in the deeper iris trabeculae) .

The syndrome of heterochromic iridocyclitis is characterized by the presence of a unilateral asymptomatic low-grade process which is devoid of congestion or pain and is slowly progressive over a long period of years. Among the important features are the change in iris coloration (as contrasted with that of the unaffected eye), the mutton- fat keratic precipitates, and the complicated cataract. The color of the iris in the diseased eye is always lighter than that of the unaffected eye. The disturbance in coloration, which usually precedes the other findings, is diffuse and at times may be very slight. Because of incorrect impressions of color that may be gained when the iris is inspected with a highly focalized light, as is obtained with the biomicroscope (page 764) , it is preferable, especially when the color change is slight, to make comparisons between the two eyes in daylight. This is especially true when both irides are blue. The affected iris loses its fluffy character, the trabeculae (in light colored irides) appear stretched, flattened and as if they were bound together by a gelatinous material. Occasional!) a radial trabecular vessel ma)'^ be seen. Especially noteworth), in addition to the atrophy of the stromal melanophores, is the depigmentation of the posterior retinal pigment layer of the iris. Transpupillar)'- retro-illumination will practically always reveal depigmentation of the pupillary margin.


904


BIOMICROSCOPY OF THE EYE


not unlike that of ordinary senile atrophy, disclosing radial streaklike or cuneiform patches of depigmented areas. Similarly the remainder of the posterior pigmented iris surface may be affected so that retroillumination will disclose multiple streaks or innumerable pinpoint holehke areas giving the iris a typical motheaten appearance. At times, owing to marked atrophy of the stroma, the posterior pigment layers will "shine” through, and the iris of the diseased eye may appear darker than the normal fellow eye (especially if it is blue or gray). Posterior synechiae are a rare occurrence in heterochromic iridocychtis. However, Vogt found a small glassy type of nodule at the pupillary border (and only rarely elsewhere) on or in the iris. The presence of such nodules in this condition has not been mentioned in histologic studies of the iris, nor did Vogt have the opportunity of studying them histologically. The finding of iris nodules would seem to strengthen the theory of infection as the etiologic factor in heterochromic cyclitis, especially the tubercle, as opposed to the hypothesis of Fuchs who postulated the action of toxins in early or intra-uterine life. Often the pupil of the lighter colored affected eye, due to changes in the sphincter, is slightly dilated and reacts sluggishly to light.

The keratic deposits are of the mutton-fat type, sometimes round, sometimes star-shaped, and usually situated in the lower parts of the cornea. In either case their edges are sharply delineated, the "smeary” or plaquelike forms not being found. In spite of the marked iris depigmentation the keratic precipitates remain white or gray; a fact that distinguishes them from the precipitates of other conditions which tend to become dusted with pigment, especially as they age.

Complicated cataract is common (Plate L, fig. 5). The opacification usually begins in the posterior cortex in the form of punctate dots. However, in contrast to the usual "cataracta complicata” (page 1167) the typical granular opacity with iridescence at the region of the posterior pole does not appear. Both nuclear cataract and anterior cortical changes soon follow so that eventually the whole lens becomes opaque. However, in the case of a man, 5 o years


SPECIFIC TYPES OF IRITIS


905


of age, the type of cataract as it developed could not be distinguished from the ordinary senile variety. Operation for cataract extraction in these eyes is well borne.

Biomicroscopic examination of the anterior parts of the vitreous, when it can be seen, frequently reveals the presence of white dots adherent to the fibrillar structure of the framework. Pigment dust in the vitreous in these cases is a great rarity. Likewise it is very unusual to find the denser and larger forms of opacities in the vitreous.

Glaucoma, a serious complication, usually appears late in the disease and may prove to be very stubborn.

Sympathetic Ophthalmitis

The type of reaction that occurs in sympathetic ophthalmitis, both in the exciting eye and in its sympathizing eye, is similar clinically in many respects to tuberculous exudative iridocyclitis. In practically all cases the exciting eye shows or gives a history of a perforating injury in the ciliary region or of a previous operational site. Mixed forms of sympathetic ophthalmitis are seen in which the exudative process is accompanied by a proliferative one in the form of nodules or efflorescences. Generally the injured eye fails to heal properly; it remains irritable and the inflammatory process, either acutely or gradually or with recurrent flare-ups, develops into a typical chronic exudative iridocyclitis. There is a tendency for the aqueous flare to remain permanent even during periods when the lesion is relatively quiescent. Keratic precipitates and varying amounts of corneal edema soon form (Fig. 336). The iris becomes thickened and discolored, and pupillary efflorescences are followed by broad posterior synechiae. Localized iris thickenings in the form of deep nodules may form with progressive exudative membranes extending from the iris to cover the lens capsule. Dispez*sed pigment granules incorporated in the exudate are frequently found. Radiating iris vessels tend to grow over the pupillar)'- edge and lie in the membrane which is adherent to the capsule. As a result of interference with its metabolism, the lens becomes cataractous. Seclusion


906


BIOMICROSCOPY OF THE EYE

of the pupil may lead to increased intra-ocular pressure but as a rule concomitant involvement of the ciliary body, choroid, and vitreous and the formation of cyclitic membranes (with retraction


Fig. 336. Sympathetic ophthalmia. (After Gilbert.)


of the wound) results in h)^potension, obliteration of the anterior chamber, atrophy, and eventually phthisis bulbi.'*'’

From the standpoint of biomicroscopy our interest in the sympathizing eye lies chiefly in the early signs that warn us of its involvement.f

As Duke-Elder has pointed out: "While this clinical picture of a low grade, recurrent traumatic uveitis with tendency to phthisis is typical, it is by no means invariable - for sympathetic inflammation may follow almost any type of condition - on the one hand a clean wound that has apparently healed rapidly and without complications and on the other a violently acute irido-cyclitis, or even on rare occasion a purulent panophthalmitis.”

t There are many references in the early literature concerning sympathetic irritation, apparently a reflex condition. In the presence of a badly diseased or injured eye the fellow (healthy) eye may suddenly become irritable as evidenced subjectively by slight conjunctival injection, photophobia and even neuialgic pains. Objectively no positive signs of real intra-ocular involvement are found. Several years ago I had occasion to encounter such a reaction recurring in an eye, in the case of a young man 34 years of age, in which the opposite eye was rendered useless by several fulminating attacks of tuberculous uveitis over a period of six months. Glaucoma developed consequent to intractable seclusio pupillae and posterior sclerotomy and cyclodiathermy were resorted to. Eventually this eye became painless and atrophic. Several months later the patient began to complain of "eyestrain,” tearing, slight blurring and occasional photophobia in the healthy eye. Careful examination revealed only a questionable injection of some of the bulbar vessels. The tension and visual fields


SPECIFIC TYPES OF IRITIS


907


When confronted with an injured eye, especially when a perforating wound involving the ciliary region has occurred, careful and frequent biomicroscopic examinations of the felloiu {uninjured) eye are mandatory. It is only by means of the biomicroscope that we are able to detect a faint aqueous or vitrous flare (see Vol. I) with or without the presence of cells. In the first few days the signs may be so slight that they may not evoke enough blurring of vision to be noticed by the patient subjectively. But one could not make a clinical diagnosis of sympathetic ophthalmitis from a complaint of visual disturbance alone, since even from the very beginning the presence of exudation in the chambers of the eye is the sine qua non of the diagnosis. However, as the exudation increases the patient usually becomes aware of it.’^'

As the flare in the aqueous becomes more turbid, cells and larger flocculi can easily be observed in the outstanding beam. B}'" this time keratic deposits will be found. Small at first, they rapidly increase in number and size until eventually typical mutton- fat precipitates


were normal. The tarsal conjunctiva was normal. Refraction demonstrated that the eye was emmetropic. Biomicroscopic examination showed no evidence of corneal edema, aqueous flare or cells in the vitreous. A mild collyria was recommended. With the use of the collyria and an application of silver nitrate 0.5 per cent once a week, the symptoms abated. A month later there was a recurrence of the "irritation” and after two more recurrences I advised that the diseased eye be enucleated. Pathologic examination of this eye revealed the residua of a nondescript exudative iridocyclitis, secondary glaucoma and general atrophy of the globe. Since this was done (four years ago) the patient has had no further irritations in his good eye. Evidently it is possible to have a "sympathetic irritation" which is not necessarily followed by genuine sympathetic ophthalmitis.

Children, for example, may have considerable blurring of vision without complaining about it; this holds true also for unintelligent adults. One would like to be able definitely to answer the question as to whether at the very outset, cellular infiltration or deposits on the framework of the vitreous occur before they appear in the aqueous cells. Only once, in a case six weeks following a cataract extraction, was I able first to see white cells deposited on the structure of the vitreous in the fellow (unoperated) eye. The patient (a diabetic) had an extracapsular operation on the left eye which was followed by low grade iritis. At the time I saw the patient in the clinic the operated eye was still inflamed and he complained of slight blurring of vision in the opposite eye. Under mydriasis the eye which had no ciliary injection showed a few white cells just behind the lens and deeply on the fibers of the vitreous. I was unable to detect an aqueous flare, even after becoming well dark-adapted and using strong illumination. 'Ophthalmoscopic examination was negative. However, two days later, the flare in the anterior chamber was marked and ciliary injection was present. Within tu'O weeks a typical plastic iritis developed. Following fever therapy and high doses of salicylates the reaction in both eyes subsided, but the lens in the sympathizing eye rapidly became cataractous. Some months later an attempted de Weeker discission on the left e5’e resulted in a violent reaction which eventually led to phthisis bulbi. This eye was enucleated. A year later the right (sympathizing) eye was operated on for cataract. This likewise was followed by a devastating reaction which ultimately ended in a shrunken globe.


908


BIOMICROSCOPY OF THE EYE


develop. Owing to the convection currents, the effect of gravity and the condition of the endothelium, they tend to be disposed in the well-known inverted triangular shaped figure in the lower cornea. Edema of the corneal endothelium occurs early. According to Vogt, transparent droplets can be brought into focus at this level by retro-illumination. As is usual in all types of iridocyclitis epithelial edema appears somewhat later, particularly as the general inflamr matory reaction increases. Cases have been reported in which the reaction abated at this stage, i.e., cells in the aqueous and vitreous and keratic deposits disappeared and recovery followed. In other words the entire reaction in the sympathizing eye may at times run a short course, similar to a mild cyclitis. In the same way, in spite of relapses of a mild nature extending over a period of years, serviceable vision may be retained. Unfortunately such happy outcomes are not the rule. Following the initial signs of exudation in the chambers of the eye, the condition either rapidly or chronically passes into the state of a progressive devastating iridocyclitis, which in most respects is similar to the picture seen in the severe exudative types of tuberculosis. The iris becomes hyperemic, discolored and thickened. Efflorescences form at the pupillary margin and together with exudative membranes which extend from the pupillary margin over the lens capsule lead to broad synechiae and ultimately to seclusio pupillae. In addition to efflorescences, nodules (described by Vogt) in or within the stroma may occur similar to those in tuberculosis. Iris vessels are commonly present and, with the formation of exudative capsular membranes, these extend over the pupillary area of the lens. Opacification of the cornea following epithelial and endothelial edema (best seen by retro-illumination), together with precipitates and secondary stromal opacities, may hinder a clear view of the deeper structures. In the same way cataractous changes may preclude inspection of the posterior segment. Increased intra-ocular pressure attends blockage of the aqueous circulation in the anterior chamber either after seclusio pupillae (with or without iris bombe) or after peripheral anterior synechiae.

In fulminating cases, exudation may be so great as to form a


SPECIFIC TYPES OF IRITIS


909


progressive hypopyon of such proportions that absorption becomes impossible. Organization may result in the appearance of a large, solid, dirty yellowish mass filling the entire anterior chamber. Such an eye stays chronically inflamed for months and either remains hypotonic or, after passing through a phase of hypertension, is hopelessly destroyed.

Essential Progressive Atrophy of the Iris

According to Ruby, about 3 5 cases of essential progressive atrophy of the iris have been reported in the American literature. Clinically, this condition is characterized by the appearance of a unilateral progressive atrophy of the iris, in which marked shrinkage and retraction of the tissue tends to form large colobomatous defects. Eventually most of these eyes are destroyed by absolute glaucoma. The condition starts with an eccentric position of the pupil, due perhaps to the fact that "the pupil would naturally be drawn to the side where the iris is less atrophic.” McKeown'^®” noted this in the case which he reported; the pupil was first vertically elongated upward and was later displaced downward, being dragged by the less atrophic iris before the progressive atrophy advanced into the upper temporal quadrant. Most of the reported cases occurred in early adult life and only in rare instances was the diagnosis made before the onset of glaucoma. The pupillary margins may show varying degrees of ectropion of the retinal pigment. High degrees of atrophy appear in the unretracted portions of the iris, leading to the formation of "holes,” which are well demonstrated by diaphanoscopy and by retro-illumination. Troncoso, who made a gonioscopic examination in McKeown’s case (Fig. 337), 14 years following the onset of the process, found several anterior peripheral synechiae. This was the first case of essential progressive atrophy of the iris in which gonioscop}’- was employed in the examination of the angle of the anterior chamber. However, it is hoped that in the future,

Fine and Barkan"*-" reported a case occurring bilaterally in a boy of nine, wJio at the age of 5 years was first brought for examination because of a deformity of pupils. Several operative procedures for control of tension failed; in one eye detachment of the retina occurred and in the other, a definite buphthalmos.


SPECIFIC TYPES OF IRITIS


911


studies of the angle will be made at the very beginning of the condition in order to determine whether the disease starts there or whether the formation of anterior peripheral adhesions is a later secondary manifestation. The etiology of essential progressive atrophy is obscure. The absence of frank signs of inflammation would indicate a degenerative process, and its late appearance possibly abiotrophy. Von Grosz suggested that it is a primary degeneration on a hereditary basis.^'®^

Polycythemia Vera (Vaquez-Osler Disease)

In contrast to engorgement of the retinal, choroidal, and conjunctival veins seen in this disease, congestion of the iris vessels occurs rarely. This may result in a reddish discoloration of the iris, especially noticeable in light colored irides. Chamber hemorrhage in this condition has not been reported. Varying degrees of iris atrophy with pigment dissemination may follow. Tirrelli has reported on the fact that he noticed a fine dustlike pigmentation unevenly distributed between the lesser circle and the root of the iris.

Lymphoma

Rarely as part of a generalized acute or chronic leukemia, infiltration of the iris with white cells may occur either in the form of massive infiltration or as circumscribed single or multiple tumors. Several authors have described isolated cases of leukemia in which the iris became affected but in which the pattern of involvement differed. Three forms were noted: (i) the nodular type in which yellowish tumors appeared on the iris surface. These resemble tubercles and during the active stage were more or less vascularized; (2) the diffuse type in which the iris assumes a grayish thickened appearance and in which the markings and trabecular relief become obliterated. This form may be complicated by the appearance of hypopyon (Weve) ; (3) the hyperemic form, characterized by extensive engorgement of the iris vessels followed by bleeding into the anterior chamber with the formation of hyphemia. Bab described a case of leukemia in which a typical exudative iritis was noted.


22 Traumatic Lesions, Cysts, and Tumors of the Iris

Traumatic (Mechanical) Lesions

F ollowing an injury to the eye, the iris alone may be affected, i.e., it may be the only part of the eye that reveals any residual damage; but, of course, other ocular structures may also be affected.

Needless to say, the type or extent of a traumatic iris lesion depends on the force and direction of the blow, the character of the insulting instrument, and whether or not the injury was a perforating one. In the absence of gross alterations, the biomicroscope is of incalculable value in revealing, especially in retrospect, the presence of minute iris changes attributable to trauma. This may be of great importance in medicolegal work and particularly in industrial or war injuries. We shall not dwell on the gross injuries or those in which (owing to severe corneal or scleral lacerations or perforations) large portions of the iris as well as other intra-ocular tissues (ciliary body, lens, vitreous, etc.) may be damaged or even extruded. This discussion will be confined to those types of traumatic iris lesions, which, owing to their delicacy, may be overlooked by the ordinary methods of examination.

Injuries, such as contusions in which no perforation has occurred but in which the force of the blow transmitted to the iris is sufficient to cause damage to it, are sometimes known as "indirect” traumatic lesions. These may result in iritis, dislocations, and ruptures of iris trabeculae, tears in the sphincter with notching of the pupillary margin, traumatic mydriasis, dehiscences of the retinal pigment layer and iridodialysis. As an immediate consequence of any injury to the iris we may find hemorrhage in the anterior chamber and/or

912


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 913

â– within the iris itself (interstitial) , occasionally general dispersion and precipitation of pigment on the boundary walls of the anterior chamber and transient exudative pupillary membranes (fibrinous) . (See Vol. I, page 572.) The conception of an anterior segment traumatic syndrome was advanced by Frenkel and was confirmed by Davidson, who studied a series of 34 cases of contusions and analyzed their sequelae. The syndrome has to do with relatively minor sequelae, the recognition of which depends to a large extent on the application of biomicroscopy. Not all the sequelae are found in every case, but the regular appearance of two or more of these changes, which are anatomically related, give credence to such a conception. The changes seen in the iris consisted of traumatic iridoplegia, small iris tears, dehiscences of the posterior retinal pigment layer of iris, radial or concentric, single or multiple, with especial predilection for the iris periphery (root) . The combination of iris dehiscences as seen by transillumination under mydriasis, in wliich sectorially a straight line chord replaces the normal arclike curve of the pupillary margin is, as Davidson states, incontrovertible evidence of a contusion involving the anterior segment. The chordHke appearance of the pupillary edge which is similar to that seen in frank iridodialysis suggests a minimal rupture or paresis of the dilator in which the sphincter is also involved. Other sequelae of the anterior segment traumatic syndrome are found extending backward from the iris root along a pathway which predominantly involves the lens equator, zonule, anterior vitreous, ciliary body, and ora serrata. These will be referred to again in the special chapters on some of these subjects.

Direct traumatic lesions to the iris are those in which the iris tissue is wounded by direct contact with an instrument or foreign body and hence can only occur with a perforation of the cornea or sclera. The distinction between direct and indirect injuries depends on whether or not evidence of a perforation can be found. Actually as far as the iris itself is concerned nearly all the alterations found in indirect injuries also may occur after direct ones.


914


BIOMICROSCOPY OF THE EYE


Traumatic Iritis. Severe direct trauma to the eyeball, either with perforation (e.g., by a sharp instrument, a foreign body or by operative means) , or without perforation, may be followed by varying degrees of acute iritis or iridocyclitis. This is evidenced by the presence of an aqueous flare owing to the outpouring of albuminous exudate and cellular elements. The cellular elements derive from the blood absorb relatively rapidly. Fibrinous coagula in the forms of pupillary membranes may appear and disappear within several hours."* Rupture of the iris tissue itself is usually accompanied by hyphema. Undoubtedly the presence of chamber exudates, fibrin, blood, and pigment excites iritic irritation. That the presence of a highly albuminous fluid or product is toxic and may induce iritis in some sensitized persons is not surprising. It is well known that this occurs frequently in retinal separation or in the presence of degenerated lens material in the anterior chamber following extracapsular cataract extraction or ruptured traumatic cataract. As in nontraumatic iritis, hyperemia of the iris, seen best in light colored irides, is manifested by increased visibility of the blood-carrying iris trabeculae, and, at times, of circular coursing vessels. Synechiae may form, and depending on the severity of the process, varying degrees of iris atrophy may follow eventually.

Iris atrophy following traumatic iritis (in the absence of tears) may in nowise differ from that seen after ordinary iritis and may be manifested by general or localized areas of stromal vitiligo or by areas of increased translucency seen by retro-illumination or by transpupillary diaphanoscopy. Alajma noted the appearance of radial lacunae, especially in the ciliary zone, by retro-illumination (transpupillary diaphanoscopy). In severe cases in which trauma is followed by prolonged iridocyclitis associated with either low or high intra-ocular pressure, the eye may eventually be lost.

On abatement of the acute phase biomicroscopic examination generally shows the presence of pigment precipitates on the posterior corneal surface, the iris, the lens surfaces, and in the vitreous. The pigment (hematogenous and uveal) tends to disappear rapidly from the anterior chamber or from the chamber boundaries (especially


See Volume I, page 573.

TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 915


from the posterior corneal surface). This is particularly true with contusions uncomplicated by chronic iritis. Examinations of such cases months or years after the accident generally fails to demonstrate any trace of pigment on the posterior corneal surface. On the other hand pigment dispersed in the vitreous tends to be lasting.

Safar described a case in which pigment deposited in the contraction folds of the iris resulted in the appearance of pigmented curved lines on the surface of the iris. I have noticed at times in traumatic iritis that the adhesions (synechiae) are composed of whitish tags - evidently exudate. Particularly in the young, migration and secondary diffuse deposition of pigment granules on the iris surface may darken it so that by comparison with the uninjured eye the iris of the injured eye becomes darker, resulting in a sort of heterochromia in reverse. The genesis of the traumatic pigmentation of the superficial iris layer has not been solved. Clinically it is indistinguishable from the ordinary pigmentation of the normal brown iris. Discoloration of the iris from blood pigment is yellowish in appearance and follows hemorrhage in the anterior chamber or in the iris stroma itself. Vogt suggests that the stimulus of the trauma or even inflammation can cause a new formation of pigment by the superficial layers of the iris.

This type of posterior traumatic heterochromia may not appear until considerable time has elapsed. Koby cited a case in which this occurred about lo years after the injury while the interval of development in Vogt’s cases was from 20 to 30 years. Posttraumatic heterochromia has also been recorded after operations for congenital cataract, especially needlings.

Kiiptuves and Tears of the Iris. Following direct contusions to the eyeballs, even without perforation, ruptures and tears of the iris tissue are very common. These may be so slight as to be overlooked unless the iris is carefully studied with the biomicroscope.

Tears and ruptures of iris tissue are usually followed by hemorrhage. Owing to the effect of gravity the blood sinks to the bottom of the anterior chamber, giving rise to a hyphemia. The lower or older part of the hyphemia becomes darker than its horizontal


PLATE LV


Fig. I. Partial rupture of the iris at the pupillary border. Traumatic cataract. Fig. 2. Rupture of the iris at the pupillar)'^ border exposing the deeper posterior leaf.

Fig. 3. Incomplete hole in the iris following penetrating intra -ocular foreign body.

Fig. 4. Linear rupture through the iris substance.

Fig. 5. Traumatic separation of the anterior leaf of the iris.

Fig. 6. Traumatic cyst of the iris.


916




TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 919


border. When the focal beam is passed through the anterior chamber above the solid part of the hyphemia, a typical Tyndall flare will be observed, caused by the suspension of yellowish or reddish brown cells. Owing to the density of the cellular material little or no convection currents will be noted.'*'

As a rule the absorption of blood following chamber hemorrhage is rapid. However, cellular deposits on the posterior corneal surface and visible aqueous flare may be present for some time, but even these tend to absorb rapidly. As soon as the blood begins to settle and to absorb, it becomes possible to inspect the iris and to evaluate the damage incurred. Where slight displacements of the pupil and irregularity in its contour are present, especially when associated with a twisting or separation of the trabecular iris system in one segment or another, trauma should be suspected.

When small, ruptures of the sphincter appear as minute radial notches in the pupil. Larger ruptures, which may even extend to the ciliary region, may be visible with the unaided eye and are differentiated from coloboma by the fact that no pigment excrescences are seen along the pillars of the defect (Plate LV, figs, i, 2). However, ruptures of the iris do not necessarily have to include the sphincter nor do they always extend through all the iris layers. They may only involve the stroma in varying locations, degrees and depths or the posterior iris face alone. An example of partial rupture of the stroma is seen in those cases in which only the frill itself is torn. Minimal ruptures or separations of the posterior iris layers involving the dilator muscle in which the sphincter may also be affected (without any visible notching of the seam) results in the characteristic D-shaped pupil. In these, the defects in the posterior iris layers may only be visible by strong transscleral or transpupillary diaphanoscopy. These dehiscences are found in the sector corresponding to the chord-shaped defect in pupillary contour and generally at the iris periphery. This type of defect of the pupillary contour is seen best in iridodialysis. Traumatic dehiscences are more liable to occur at the periphery where the iris is thinnest. By diaphanoscopy or


See Volume I, page 577.

520


BIOMICROSCOPY OF THE EYE


retro-illumination they appear reddish in color. They may be single or multiple. The smallest ones may be seen as faintly glowing dots. Others, larger, are round, irregular or radiating, not unlike the atrophic lacunae seen in senility or iris atrophy (glaucoma, postinflammatory, etc.).

Tears of the sphincter per se also result in changes of pupillary contour. Even the smallest tears which result in a minimal notching will cause moderate dilation of the pupil. This will be permanent. Unless bridged by inflammatory exudate torn edges of iris tissue do not cicatrize. Consequently separations in iris tissue, whether traumatic or operative, are permanent. Multiple radial lacerations of the sphincter and larger tears correspondingly result in greater pupillary dilation and deformation.

Faulty action of the sphincter may cause folds by releasing the tension of the iris fibers, and in the same way some torsion of the adjoining fibers results. This torsion of the fibers adjacent to the torn area is characteristic; they assume a corkscrew aspect, in contrast to the normal radiating and somewhat stretched appearance seen with the pupil undilated. Partial or complete separation of the superficial stromal leaf from the deeper stromal layer has been reported many times after injuries. When extensive this may simulate the so-called "senile detachment.” The detached superficial portions may float freely in the anterior chamber and noticeably do not follow movement of the iris. As a consequence the detached parts do not move with dilation of the pupil.

Holes in the iris, secondary to perforating injuries, particularly with the passage of small foreign bodies into the deeper parts of the eye, may be missed unless transpupillary retro-illumination is performed (Plate LV, fig. 3 ) . They should always be looked for especially when a scar traversing the corneal layers is found. Occasionally some depigmentation of the iris surface (atrophy) will be noted in the immediate neighborhood of a hole. Since most perforating foreign bodies strike and enter the eyeball obliquely iris holes occur more commonly in the ciliary zone.

Iridodialysis or separation of the iris from the ciliary body like


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 921


wise may follow nonperforating injuries as well as perforating ones. It practically always is attended with marked chamber hemorrhage and frequently is not noticed until the blood is absorbed. As in the case with severe iris ruptures, pigment dispersal results.

Depending on the injurjq an iridodialysis may be so slight as to appear as a linear black crescentic slit at the periphery of the iris, seen with difficulty and at times only when the patient’s eye is moved peripherally in the direction of the lesion so as to permit the observer to inspect the far angle of the chamber. Such extreme peripheral tears are best studied gonioscopically. In iridodialysis the pupillary margin in the affected sector always slopes off to form a straight line. Larger separations permit the view of the lens equator and the zonule. With these the iris is thrown into lax folds running more or less parallel to the separated iris edge.

Iiifevsfiiial Iris Hemorrhages. Ruptures and tears of the trabecular tissue of the iris is usually accompanied by chamber hemorrhage. However, bleeding within the iris substance itself may occur. When this happens, there may be no outward indications of its presence when the iris is viewed by diffuse or direct focal illumination. The blood confined to the deeper iris layers can only be seen by indirect illumination. Observation of the iris adjacent to the part illuminated by the focal beam, will reveal a reddish glow. Unless looked for carefully soon after the injury this type of suggilation or interstitial hemorrhage of the iris can easily be overlooked. In a case which came under my observation in which suggilation occurred in a lightly colored iris, examination 6 months after the trauma revealed a slight darkening of the iris as compared with the uninjured fellow eye. The superficial stroma of the iris assumed a yellowish brown hue, evidently a form of permanent blood staining. Von Hippel stated that a long standing hemorrhage in the anterior chamber and in the vitreous as well may result in a form of hematogenous siderosis. In most instances, however, blood is rapidly absorbed and leaves no trace. According to Wolff the importance of the iris in the absorption of a hyphemia is illustrated in chamber hemorrhages following an iridectomy. The blood disappears rapidly over


522 BIOMICROSCOPy OF THE EYE

the iris but may remain a much longer time in the area of the toloboma. He showed an illustration of a histologic section of iris from an eye which was removed 24 hours after a perforating injury, in which the blood on the front of the iris is entering it by one of the crypts. The phagocytic function of the iris is probably of considerable aid to the main drainage system (Schlemm’s canal) in cleansing the anterior chamber not only of blood but also of other noxa.

Interstitial iris hemorrhages may involve a considerable portion of the iris stroma or may be localized as small ecchymotic spots. When searching for such spots one moves the focal beam slowly across the iris face, looking the while at the unilluminated portions on either side of the brightly illuminated part. A hemorrhage will glow slightly reddish in the somewhat darkened areas in the faint light of indirect illumination. As soon as the beam itself falls over the area of the hemorrhage, this reddish glow is lost since it is obscured by the brilliant illumination and reflexes of direct focal illumination.*

SIDEROSIS OF THE IRIS

Following the introduction and retention of a ferrous foreign body within the eyeball, within a certain time (latent period - from a few weeks to years) definite changes may occur. Owing to chemical changes the iron is converted into a diffusible form and is disseminated by the tissue fluids (especially the aqueous and vitreous) . It then stains, according to Wolff, all the structures with which it comes into contact, so that all structures bathed by aqueous and vitreous will be affected. As noted with vital staining (see Vol. I), highly differentiated cells (epithelium, nerves, etc.) take up dyes readily. Also the phagocytic action of epithelial cells is well known. It is not surprising then in siderosis that the iris (anterior border layer), ciliary epithelium, lens epithelium, and retina (especially ganglion cells and neuro-epithelium) are first stained. After being taken up by these cells, the iron is probably reconverted into an insoluble form. Eventually through interference with metabolism the affected cells degenerate.


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 923

The toxic effect of siderosis within the globe is illustrated by the accompanying iridocyclitis. This varies in severity but usually is indicated by the presence of a long standing aqueous flare. Concomitantly bedewing of the corneal epithelium, endothelium and keratic precipitates occur. When this is found in conjunction with a yellowish to brownish discoloration of the iris surface (as compared to the fellow eye) , siderosis should be suspected. If added to these there is a perforating corneal or scleral scar and the characteristic rust stain below the lens capsule (page 1281) (the lens soon becomes cataractous) the diagnosis is almost certain. Histologically in the iris, the staining (Perl’s reaction) is most marked in the anterior border la3'-er and in the sphincter and dilator muscles. Involvement of the latter may account for the commonly occurring incomplete mydriasis. The diffuse rusty discoloration of the siderotic iris differentiates it from the normal pigmentation of an unaffected brown iris (Plate LXXVI, fig. 2). The color change in siderosis of the iris depends on the original iris coloration and on the degree of involvement. In the case of a blue or gray iris it may change to greenish yellow or even light brown. If the iris originally was brownish then it may become darker. At any rate its color will certainly differ from that of the unaffected fellow eye. Especially important is the fact that the normal trabecular structure of the iris becomes indistinct, the iris surface becomes flattened, and there is a peculiar loss of luster - a manifestation of iris atrophy. Posterior synechiae to a cataractous lens exhibiting reddish-brown rust stains, completes the picture. Transpupillary retro-illumination of the iris at this stage is not always possible but transscleral illumination will reveal the typical lacunae of iris atrophy.

Cysts

The biomicroscope affords unusual means of viewing and studying cysts of the iris. When confronted with a swelling or bulge in the iris, our first concern is to determine whether the structure is solid or cystic. In the case of a cyst, indirect illumination (i.e., placing the beam to one side of the lesion) will in most cases reveal its semi


924


BIOMICROSCOPY OF THE EYE


transparent nature. A similar effect can be obtained b}^ viewing the iris indirectly by a modified form of scatter. The beam is directed to the corneoscleral junction, and the swelling in the iris is then observed while oscillating the beam to and fro over the cornea for a distance of from 2 to 3 mm. Sufficient light is reflected to transilluminate the involved area of the elevated iris (Plate LV, fig. 6). The importance of demonstrating this translucency will easily be understood when examining dark iritic masses, especially when a differentiation between a pigmented cyst of the posterior retinal epithelial layers and a malignant melanoma is necessary. Given an iris cyst, it is not always possible to make an etiologic diagnosis biomicroscopically, but it may be possible by exclusion to narrow down the probabilities. The biomicroscope will aid, for example, in deciding whether or not inflammatory signs, i.e., keratic precipitates or synechiae, etc., or evidences of trauma (corneal scars, ruptures of the iris, dispersal of pigment, alterations in the lens) or of a previous operation (coloboma or aphakia, etc.) are present. In an adult, only in the absence of a history of trauma or surgery or of any of the above signs might one be justified in the early stages in diagnosing a cyst as of spontaneous origin. In most instances the wall of the cyst is thin regardless of etiology or location. As a cyst develops, the iris trabeculae of the superficial layers that form anterior limiting layers of the cyst are pushed aside and become atrophic. This leaves a white, yellowish, or pearl-gray smooth surface with a characteristic silky gloss. Continued growth of the cyst tends to separate the atrophic mesodermal layers from the posterior pigmented la^’^ers. In such cases the posterior pigmented layer may even become the posterior wall of the cyst and after bulging backward it may even extend into the posterior chamber. There, in certain instances, it can be seen as a dark globular mass in the pupil. These types of dissection are destructive. The iris adjoining the cyst may exhibit varying degrees of atrophy, but more commonly it is pushed aside and folded. These folds are concentric to the rim of the cyst. Such stretching and pulling causes displacements and distortions of the pupil. At times, larger cysts may actually cover the pupillary


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 925

opening, partially or completely. Tlie lack of resistance anteriorly permits easy expansion in this direction, so that as the cyst develops, it eventuall)’- comes in contact with the posterior corneal surface.

Meeting the resistance of the cornea it adjusts itself to the curvature of the posterior corneal surface and may ultimately cause corneal opacification. Posterior extension may result in further iris atrophy, luxation of the lens, and cataract. If the cyst is not destroyed (by removal, by aspiration and injection of a sclerosing solution, or b)'- diathermy, etc.), loss of the eye from glaucoma or secondary inflammation may in time occur.

As Duke-Elder has pointed out, the classification of cysts on an etiologic basis is uncertain, since in most instances (excepting only the traumatic and parasitic cysts) it is not possible to explain their occurrence. With this in mind he has classified them from the clinical standpoint as follows: *•'

I. Congenital cysts

II. Parasitic cysts

III. Traumatic implantation cysts

IV. Exudative and degenerative (secondary) cysts

V. Spontaneous or idiopathic cysts

A. Stromal (epithelial, endothelial)

B. Cysts arising from the pigmentary epithelium

CONGENITAL CYSTS

Theoretically two types of congenital iris cysts are possible, but clinically and even histologically it may be impossible to differentiate between them: (i) stromal cysts, apparently caused by implantation and growth of surface epithelium, corneal or conjunctival, within the stroma of the iris and (2) those derived from the posterior pigmented (retinal) epithelium. The former, similar to dermoid cysts of the conjunctiva (described by Straeten and v. Duyse ““^) may start as small blebs within the iris stroma and may grow to a large size, eventually forming large semi-opaque globes

Gilbert*®® has classified them as (i) implantation cysts, (2) cysts of the iris stroma, and (3) cysts of the pigment layer; while N. Teulieres and I. Beauvieux“® have designated them (i) traumatic cysts, (2) parasitic cysts, and (3) spontaneous cysts.



TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 927


extending into the anterior chamber. (See Fig. 338; Plate LVI, figs. I, 2.) The second variety may result from failure in fusion of the two primitive la^'^ers of the optic vesicle (those of the pupillary margin [e.g., see flocculi, page 787] from lack of closure of the marginal sinus) or they may be derived from cells detached from the posterior pigment la^'-er or from those in direct continuity with it. Normally, derivatives of these cells form the musculature of the iris (page 733) and also the clump cells of Koganei. Aberration in development of these migratory cells may result in the formation of cysts.


PARASITIC CYSTS OF THE IRIS

Cysficerciis. Invasion of the iris by the cysticercus loa has been reported several times. The cyst appears as a transparent bubble varying in size, the interior of which may contain a whitish opaque nodule - the actual head of the parasite. Characteristic movements of the parasite within the cyst distinguishes it from other forms of cysts. At times the parasite may emerge from the cyst. If it is not removed, a violent plastic iridocyclitis may develop. This is frequently complicated by hypopyon and eventually complete opacification of the cornea.

TRAUMATIC IMPLANTATION CYSTS

Two forms of traumatic implantation cysts have been described: (i) the so-called "solid” or "pearl” tumors or cysts

(epidermoid) and (2) true serous cysts (translucent). These types of iris cysts form as a consequence of implantation epidermal cells (especially in association with implanted eyelashes) or of surface epithelium, corneal or conjunctival, either as free particles or as a continuous ingrowth between the lips of perforating surgical or traumatic wounds. It should be remembered that the term "pearl cyst” is correct only morphologically, since histologically, degeneration of its contents (fatty or cholestrol changes) may result in the formation of a translucent cyst, indistinguishable even with the


PLATE LVI


Fig. I. Congenital cystic-like mass in the iris periphery.

Fig. 2. Congenital cystic-like mass with deformity of the pupillary curvature. Fig. 3. Benign mass of the iris (congenital).

Fig. 4. Nonmalignant melanoma of the iris. (Diffuse illumination.)

Fig. j. Same case as Figure 4, viewed by direct focal illumination.

Fig. 6. Tumor of the iris. Nonmalignant. (After Messmann.)


928



TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 931


bioniicroscope from the true translucent ones. Hence strictly speaking, the designation "pearl cyst” clinically refers to cysts whose surfaces have a dull, gray luster, comparable in appearance to that of a "black” pearl (Fig. 339). They may be either epidermoidal (which begin as solid growths) or of a true serous character (from the implantation of non-keratinized corneal or conjunctival epithelium) .

It is usually only in the early stages following a perforating injury when the presence of implanted lashes in the eye can be seen, that it is possible from the morphologic standpoint to diagnose a cyst as truly epidermoidal in character.

Epidermoid (iJ Tumors or Cysfs C^PeaiT^?) . Epidermoidal tumors or c^'-sts start as more or less solid, whitish nodules within the iris or on its surface (Fig. 339). Their color and smoothly reflecting mother-of-pearl surface differentiate them from structures of different origin (true neoplasms). The biomicroscope frequently demonstrates that their walls are made up of concentric layers. Unless liquefaction occurs the contents are solid. Histologically these contents consist of a waxy substance admixed with cells more or less degenerated. These cells are chiefly epithelial in origin since apparently it is only epithelium that will survive and grow when implanted into the anterior chamber. The tumor consists of a cover of epithelium enclosing the waxy core mixed with cells; in the center there is a lash which is the cause of the new growth.

A large percentage of them have been seen in children and young people following perforating injuries by sharp instruments (scissors, knives, etc.). Buhl and Rothmund (1872)®^^ first explained their origin. In most instances pearl cysts of the iris followed the accidental implantation of eyelashes to which small pieces of epidermis were

Pathologically real pearl cysts consist of keratinized lamellae. Such "hornlike” changes would indicate that they originate from implantation of skin rather than from corneal or conjunctival epithelium. These epidermoidal cells probably arise from the root of the cilia. Silva (1905)®“® has emphasized that only the cilia of the young have germinal cells attached to their roots, and that the physiologic growth of these cells occurs when they are implanted in the iris. The shaft of the lash itself may be lifted away from the iris Isy the growing cells which attach its root to the iris. According to Gilbert, the iris plays only a small part in the genesis of a true pearly cyst. The iris tissue forms a fertile media for its growth and helps to form its walls.


^32 BIOMICROSCOPY OF THE EYE

attached. In recent cases in which the cyst is already developing the eyelash may be visible clinically but with time bleaching of the pigment within the eyelash causes it to resemble a white line (Wintersteiner ) . It usually takes from three to six months for the cyst to develop. Its growth is not steady but is characterized by periods of inactivity alternating with periods of rapid growth and secondary irritation. These cysts may attain great size, occupying a sector of the iris and extending from the chamber angle to the pupillary margin, projecting forward until they reach the cornea. Blondel described a cyst the size of the lens filling the anterior chamber ; this cyst required six months to develop. Eventually, such cysts interfere with drainage and cause increase in intra-ocular pressure; a complication subjectively attended with pain, inflammation and visual failure.

True and Serous Cysts. By far the greater number of iris cysts fall into this category. These are the ones commonly seen following perforating injuries and operative procedures (Plate LV, fig. 6). Those following injuries are generally found connected or related to a corneal scar near the limbus (Fig. 340 C) . They are usually thinwalled, may be uni- or multi-ocular and often have an irregular sausage-like shape. In diffuse light, depending on the amount of residual iris tissue covering them, they may have a characteristic appearance so much like a "black pearl” that in my opinion at times they deserve the name "pearl cyst” even more than do the epidermoidal cysts (described above) . In some cases the dull pearly sheen may be masked by the presence of whitish lines over the surface, the remains of stretched iris trabeculae. In such cases, it will often be seen that at the peripheral edges of the cyst, these fibers are pigmented (in brown irides), and gradually merge into the surrounding iris stroma from which they are derived. By pressure, the adjacent iris stroma is frequently thrown into concentric folds. These cysts, which so often start at the periphery, tend to grow in a concentric manner; but owing to lesser resistance in the anterior chamber they soon bulge forward and commonly cover the pupillary opening in part or completely (Fig. 340 A, B). Cases have been seen histologi


c


Fig. 340. A. Double cyst of the iris. b. Same cyst after operation, c. Cyst of the iris. Note

corneal scar. (After Buonacolto.)


933


934


BIOMICROSCOPY OF THE EYE


call}^ in which the cyst was attached to the anterior lens capsule. Parsons described a case in which the cyst formed in the posterior chamber. The anterior wall of the cyst was formed by atrophic iris, which was completely adherent to the posterior surface of the cornea, the posterior wall of this cyst was bound by an epithelial layer that covered and was attached to the ciliary processes and the lens. On reaching the posterior corneal surface, to which it may become adherent, the surface of the true or serous cyst flattens out and lateral extension may ensue. Examination with the narrow beam generally reveals the walls of the cyst and the transparent slightly opaque fluid content. The anterior surface, indicated in optic section as a line, will have a brighter yellow color while its posterior boundary (retinal pigmented layer) is dull brown. As previously mentioned, posterior dissection and extension into the posterior chamber may occur with or without extension into the anterior chamber. In the latter case the cyst may be seen through the pupil as a dark, smooth globular mass.

In epithelial cysts of the anterior chamber, especially those following cataract operations (when the epithelium grows down between the lips of the wound), the epithelium-covered iris surface forms the posterior wall of the cyst. Biomicroscopic inspection at the site of the wound may reveal vessels passing posteriorly through the entire corneal or limbal thickness. The ingrowing tracts of epithelium extend into the chamber angle over the iris. Since epithelium is less respersive and relucent than the corneal stroma (see Vol. I), such tracts will appear dark as compared to the grayish opalescence of the surrounding tissue. Histologically the posterior wall of the cyst lies on the iris surface and is composed of parchment-like epithelium. Endothelial (traumatic) cysts of the iris are rare and follow direct trauma to the iris itself. The lumen of the cyst is lined by the endothelium of the iris surface or what appears to be mesodermal iris tissue. It usually follows folding or pleating of the iris associated with extensive anterior and posterior synechiae and consequently the liquid contents of such cysts is derived from the aqueous. In the same manner, retrocorneal cysts, in which proliferation of the cor


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 93 5


neal endothelium is a factor, may enlarge and contact or become incorporated in iris tissue. Extension of the ingrowing epithelium along a corneal wound in connection with anterior chamber cysts may form large pericorneal cysts which in the end may become larger than the entire globe."®®

EXUDATIVE CYSTS OF THE EPITHELIAL LAYERS

Separation of the retinal layers of the posterior surface of the iris by fluid or exudate is the result of stasis after inflammation; it may also result from conditions in which there is a severe interference with the iris circulation, as in glaucoma, or as a consequence of sudden lowering of the intra-ocular pressure (e.g., from paracentesis) . Fixation of the deeper layers of the iris epithelium to the lens or to a cyclitic membrane undoubtedly also aids the development of such a separation. The secretory and proliferative property of these cells and the resultant tendency to cyst formation has already been noted in the discussion of the cystic flocculi (page 786). The anterior bulging of the iris stroma of such a cyst formation may resemble iris bombe. I recently saw a case in which a large posterior iris cyst developed after discission of a secondary membrane. The stroma of iris, which was only slightly compressed, protruded forward on the temporal side almost touching the posterior corneal surface. It was impossible to transilluminate the cyst’s contents or to demonstrate a cavity by the optic section. However, with a hypodermic syringe it was possible to withdraw about Yz cc. of a clear straw-colored fluid. Without withdrawing the needle itself a similar amount of 2 per cent tincture of iodine solution was injected. This caused a slight ballooning of the cyst. In a few weeks it could be seen that the walls had adhered to one another. Wilmer ®”® observed a case of chronic uveitis in which numerous small pedunculated cysts were seen at the pupillary border. Frequently these cysts of the epithelial layers of the iris are found histologically in eyes badly crippled from chronic inflammatory disease and glaucoma. In a case reported by Collins there was a malignant melanoma of the ciliary body.


936


BIOMICROSCOPY OF THE EYE


SPONTANEOUS CYSTS OF THE IRIS

In rare cases, cysts of the iris are found whose etiology cannot be explained either by the history or by the objective findings. These cysts may either be stromal in type or may develop from the posterior epithelial layers. The fact that these cysts are seen most commonly in the young (without signs or a history of trauma) would strongly suggest the presence of a developmental anomaly. It is difficult to explain how or when a migration or implantation occurs of the several different types of cells which line the stromal type of cyst. It is easier to explain the formation of the spontaneous cysts of the posterior epithelial layers since embryologically these layers are separate. Failure in fusion from some cause during fetal life seems to be a logical explanation for the formation of such cysts.

Tumors

The benign nevi and melanomas are discussed on pages 766-767. Here we shall briefly consider leiomyoma, angiomas, the malignant melanoma and carcinoma.


Leiomyoma

There have only been about eight cases of this rare type of iris tumor reported in the literature (Fig. 341). Clinically it is indistinguishable from malignant melanoma and it has been diagnosed only histologically with special stains that disclose myoglial fibers. In only three instances has the diagnosis been verified pathologically (Verhoeff, 1923; Frost, 1936"^®“ and Ellett, 1939^^®). This type of epiblastic tumor probably arises from the sphincter muscle. Frost in describing his case, states, ”it was a small circumscribed nodule, yellowish-gray in color, the surface near the pupillary border being dotted with pigment. There was also an ectropion of uveal pigment at this point, producing a somewhat pear-shaped pupil. This ectropion was I mm. in width and showed the radial columns of dark brown pigment of the posterior surface of the iris. It suggested that


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 937


the iris had been turned inside out by contracture of the tissues in the anterior layers. The growth appeared to have increased the thickness of the iris about i mm. and extended from the pupillary


Fig. 341. Leiomyoma of the iris. (After Frost.)

margin to a little more than one-half the width of the iris. The mass was wedge-shaped with its apex directed toward the pupillary margin, and extended from 4 to 6 o’clock (Fig. 341). The thickest portion was near the pupillary margin and gradually grew thinner toward the root of the iris. Small blood vessels were visible in the stroma making their way in the iris tissue from the periphery toward the mass. A dilated tortuous anterior ciliary vessel was seen in the same sector as the tumor. There were no precipitates on the posterior surface of the cornea, and no evidences of active inflammation were present. Histologically, it was a vascular tumor composed of interlacing bundles of closely packed elongated spindle-shaped cells with considerable granular eosinophilic cytoplasm and long oval nuclei. The tumor is of greater thickness at the level of the sphincter irides, with which it appears to be continuous. Differential staining with the gold impregnation method also revealed the presence of the characteristic myoglia fibrils and a diagnosis of leiomyoma of the iris was made.”


Angiomas

Several cases of hemangioma of the iris have been reported in the literature. According to Duke-Elder only the one reported by Rodin (1929) was proved histologically. Angiomas have been described as


53 8 BIOMICROSCOPY OF THE EYE

highly vascularized circumscribed tumors that protrude from the iris surface and that tend to bleed easily. De Wecker described a case in which a pea-sized angiomatous growth resembled a blackberry in appearance.

The occurrence of such growths in connection with SturgeWeber’s syndrome (nevus flammeus) of the face and with glaucoma or buphthalmos has been noted on several occasions (Knapp, 1928; Tyson, 1932; Evans, 1937“^"). In the case of a young woman who had nevus flammeus, glaucoma, and engorged conjunctival vessels (Vol. I, page 249) , several large tortuous vessels were seen in the iris. This was also noted by Evans in a iz-year-old boy in whom nevus flammeus was associated with hemangioma of the choroid. In Daily’s case, a 5 -month-old infant, there was a very narrow dark-brown growth in the angle of the anterior chamber. There was considerable blood in the anterior chamber, and the eye was hard. Histologic examination revealed a hemangioma of the ciliary body, which projected into the anterior chamber at the infiltration angle for about 2 mm. This portion was necrotic and most likely was the source of the hemorrhage. Vascularized growth masses in the iris simulating angiomas have to be differentiated from the granulomas and from malignant growths, especially the so-called "leukosarcomas.” This requires a biopsy in most instances. In this connection, the so-called vascularized connective tissue growth - nevus vasculosus - should be mentioned. This type of growth tends to develop in the neighborhood of the sphincter. Fuchs (1913) described it as a vascular tumor of congenital origin. They may remain silent for many ^ears or at times begin to grow. Active growth of such a lesion would indicate that it represents a new growth of the vessels themselves.


Malignant Melanoma of the Iris

Today benign melanoma and malignant melanoma as well (following the classic ideas of Masson, and with specific reference to the eye, those of Theobald) are considered to be neuro-ectodermal in origin, deriving from the cells of Schwann. The reader is referred to the original papers on this subject. Actually primary malignant


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 939


melanoma in the iris is very rare. In most cases histologic evidence will reveal forward extension into the iris from tumors in the ciliary body. Although a considerable number of cases have been reported in the literature in which malignant melanomas have been observed to arise from previously seen pigmented spots or freckles (Reese), it is not at all certain that this is so. For instance, Fuchs (1917) thought that pigment spots previously seen at the site of a malignant melanoma were not physiologic iris pigment spots or nevi but actually the early evidence of an already slow-growing malignant melanoma. In addition there is the added fact of the rarity of malignant melanoma as compared to the universality of the so-called "physiologic pigmented iris spots.” On the other hand, the tendency to malignant growths in eyes having melanosis oculi has been noted many times. It would seem that eyes that are abnormally pigmented congenitally are more predisposed to develop malignant melanomas. This is also the case in persons with skin nevi. In other words, those in whom a tendency to congenital pigment exists are more likely to develop malignant melanomas than others. However, the tumor does not necessarily develop at the site where the congenital pigmentation is most marked. This point was brought out by Van der Hoeve’s observation (1924) in which there were numerous black spots in the fundus of a right eye of a man, who in his left eye had a malignant melanoma removed by iridectomy. Recently, Reese has shown the frequent occurrence of benign melanomas (pigment freckles) of the iris in microscopic sections of eyes harboring malignant melanomas of the uveal tract.

Reese states: "The histologic difference between the melanomas of the iris seen in normal eyes and those seen in eyes with malignant melanoma seems to be one of degree. In the case of the normal eye the lesion is a localized accumulation of densely pigmented melanoblasts only a few cells thick along the anterior surface of the iris. In fact the lesion could be characterized as merely a localized thickening of the anterior limiting layer of the iris, which in some instances has the appearance of being proliferated endothelium. Such a lesion may sometimes contain little or no pigment (similar to Wofriin bodies [author]). The melanomas of the iris in eyes with malignant melanomas are more extensive lesions. They tend to be slightly more elevated above the iris surface and to extend deeper into the iris stroma." Considering the nature of the multiple manifestations of melanomas, he gives consideration to the idea that perhaps some cancerigenic agent acts on the whole uveal tract causing a malignant melanoma at one site and more or less benign melanomas at other sites. This is in line with what occurs elsewhere in the body, notably in the Phakamatoses (von Recklinghausen's disease).


940


BIOMICROSCOPY OF THE EYE


Biomicroscopically, it has not been possible at an early stage to differentiate between a simple physiologic iris freckle (benign melanoma) and a malignant growth, although differences (degrees of maturity) in the character of the cells must exist. Nor is it always possible in the early state to recognize the transformation from the benign to the malignant status, especially when development is slow. It has been suggested that the appearance of vessels in the iris or even at the limbus in the sector occupied by the lesion is a significant indication of such a change. In several cases of malignant melanoma, which came under my observation, I could make out no increase in vascularity in the iris, even after the mass attained considerable size. However, secondary effects (toxic and pressure) may cause the appearance of even very large iris vessels in the neighborhood of a tumor. This is usually a manifestation of a late phase, as a criteria of malignancy. Vascularity of the lesion itself is better manifested in leukosarcoma and in carcinoma. Undoubtedly the sine qua non in this differentiation is visible signs of progressive growth. Repeated biomicroscopic examination with accurate measurements (using the ocular micrometer) is of greatest importance in detecting changes in shape, volume, or extension, all characteristic of growth. Enlarged anterior segment kodachrome photographs are valuable in recording the actual appearance and changes.

It has been long recognized that malignant melanoma of the iris may occur in young individuals, and even at an earlier age than in the choroid. The growth, as previously mentioned, may start as a dark brown to blackish spot anywhere on the iris surface, indistinguishable from an ordinary physiologic freckle. Gradually and quietly over a period of months, years, or decades it increases in size and thickness, eventually projecting from the iris surface to form a well-defined nodule. Its surface soon tends to become bossellated and corrugated (Plate LVII) . However, I have seen cases in which the surface remained smooth and velvety. In these the tumor invaded the iris from the ciliary body either anteriorly at the chamber angle or appeared in the pupillary area after extending axially just behind the iris in the posterior chamber. Frequently it happens that small


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 941


freckles are seen in the meighborhood or elsewhere on the iris surface. If these were not previously present, i.e., before the appearance of a tumor, they might represent daughter growths, either multiple origins, implantations, or direct extensions. Only close observation over long periods of time with the biomicroscope to determine active growth will answer the question as to whether these freckles are benign (congenital) or are part of the malignant process. In any event the appearance of new freckles on the iris in the vicinity of a tumor should be looked on with suspicion. This holds true not only for well-formed flat freckles but even for pigment dust, dispersed over the iris surface. This is demonstrated by a case of Gilbert’s in which a distinct difference in color and regularity of the iris surface occurred as compared to that of the unaffected eye. Pressburger (1932) reported on the character of tumor cells dispersed on the iris and lens capsule. With the biomicroscope he saw "sarcoma” cells on the anterior lens capsule. They appeared in the form of fine lines and starlike, branching, gray to brownish spots. Characteristically these cells had long processes (outriders) which he believed differentiates them from the well-known small starlike cells seen in congenital remains of pupillary membranes. In every case, particularly if the tumor is seen in the peripheral parts of the iris, it is important to know whether the tumor is primary to the iris or whether it is an extension from the ciliary body. This question is very important (though frequently insoluble) when the tumor seems to arise from the iris root since one originating in and localized to the iris might conceivably be removed by iridectomy whereas extension into or from the ciliary body demands an immediate enucleation. Unfortunately, after the tumor in the region is raised above the iris surface, it usually is not possible to inspect the chamber angle just back of it. The wider the base of the growth is at the iris root the more likelihood there is that it originates from or involves the ciliary body. This is especially true with the rarer flat or ring type of malignant melanoma. As in the case of the ciliary body, the natural circular architecture of the iris tissue at the lesser circle and at the iris root favors ringlike or circular extension. Such an infiltration may occur


942


BIOMICROSCOPY OF THE EYE


within the stroma so that very little thickening or elevation above the iris surface is seen. But as a rule clinically the iris assumes a peculiar dirty brown to black discoloration. Adjacent parts of the stroma may undergo varying degrees of atrophy and vitiligo; as a result the iris assumes a grossly mottled appearance in which darkly colored tumorous areas are sharply contrasted with depigmented areas. Occasionally it has happened that histologic examination reveals that the entire iris stroma has been replaced by such a form of growth. Although the site of the origin of malignant melanomas of the iris is probably the anterior border layer deeper involvement within the posterior pigmented retinal layers can also occur.

Several cases reported by various authors has demonstrated the fact that extension of tumor growth from peripheral parts of the iris to the ciliary body may occur. Reese has reported such a case. Malignant melanomas arising at the lesser circle or in the pupillary zone tend to grow toward the pupillary margin and generally reach this area long before they involve the ciliary zone and chamber angle. Extension into the pupillary zone causes pupillary distortion and even visual disturbances if part of the mass encroaches on the pupillary area.

No two tumors grow alike or at the same rate of speed, and consequently it is not always possible to classify the stages of growth. Anterior chamber hemorrhage may occur at any period. An initial quiet period may be followed by increased intra-ocular pressure with inflammatory symptoms, complicated cataract, and eventually blindness."' Extra-ocular perforating extensions may or may not occur. In one case this was the first manifestation of a malignant melanoma of the ciliary body. Two small black spots, about 0.5 mm. in diameter, appeared below in the sclera in the vicinity of one of the dilated episcleral veins. Two years later a small nodule was seen on the iris near its root on the angle of the anterior chamber in the same sector (below). Six months later, with the pupil widely dilated, a large

- It is conceivable that with marked degeneration and shrinkage of the eye and as a result of spontaneous necrosis from cutting off the blood suppl)% choroidal tumors may be found accidentally in shrunken globes.


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 943


bulging mass extending toward the vitreous could be seen below extending from the ciliary body (Plate LVII, fig. i ) .

Leukosarcomas

This type of nonpigmented iris tumor is rare. It is easily recognized by its yellowish-white color and high degree of vascularization (Plate LVII, figs. 2,3). The vessels may stand out as thick, widened cords and hemorrhages in the anterior chamber are common. The tumor may start out as a small nodule, but after slow progressive growth it may infiltrate the entire iris. Frequently forward extension occurs from a primarj'" tumor of the ciliary body into the chamber angle and iris. As with melanotic tumors, involvement of the ciliary body may be followed by extra-ocular extension early in the overlying scleral area by means of the emissaria. In the same way tumors involving the chamber angle cause interference with the drainage channels and secondary glaucoma may rapidly supervene. Zentmayer reported a case in which a small mass, arising in the pupillary zone, encroached over the pupillary border. It was entirely removed by iridectom)^

Metastatic Carcinoma of the Iris

Metastatic carcinoma of the iris occurs much more rarely than in the posterior parts of the choroid. According to Sanders only 4 cases are on record in which the growth has been shown histologically to be limited to the iris itself. In cases reported by Toulant in 191(3 (not examined histologically) both irides were involved. In 2 out of these 4 cases the primary lesion was in the breast. *'â–

In the iris as elsewhere in the uvea, the histologic structure of the growth duplicates that of the primary lesion (mucous or glandular)

According to Lemoine and McLeod:®^® "Carcinoma of the breast tends toward hematogenous metastasis, releasing comparatively large numbers of cells into the circulation. A certain proportion of these cells find their w.ay into the ophthalmic artery and are distributed to the tissues supplied by it. Those which reach the choroid through the posterior ciliary arteries and, to a less degree, those which reach the iris and ciliary body through the anterior ciliary arteries find nutritional conditions suitable to grow, elsewhere they perish. The difficulty of entrance into the ophthalmic artery (this vessel arises from the internal carotid artery at a right angle [M. L. B.} ) may partly account for the low frequency of ocular metastasis. In other words, we are postulating a specific affinity of uveal tissue, particularly the choroid, to cells from carcinoma of the breast.”


PLATE LVII


Fig. I. Fig. 2. Fig. 3. Fig. 4. Fig. j. Detached


Malignant melanoma (melanosarcoma) of the iris with deformed pupil. Leukosarcoma. Diffuse illumination.

Leukosarcoma. Same case as Figure 2. Direct focal illumination. Malignant melanoma of the iris (deformed pupil) .

Malignant melanoma of the ciliary body extending into the iris, above, particle, below.


944


TRAUMATIC LESIONS, CYSTS, AND TUMORS OF THE IRIS 947


and clinically usually appears as small well-defined nodular to massive swellings, varying from )'^ellow to grayish brown in color located an)'wliere or in any zone of the stroma. These lesions are well vascularized, the vessels var)fing in size. Sanders’ case occurred in a woman who six years previously had a hysterectomy^ Below at the base (root) of the iris there was a flesh colored mass about the size of a pea having a few dilated vessels on its surface. There were no signs of active inflammation. The pupil was dilated and fixed, and the intra-ocular pressure was elevated. The fundus was normal. Within two months the tumor grew rapidly until it almost filled the anterior chamber. A grayish infiltration was noted deep in the lower half of the cornea. Eventually the invaded cornea ruptured. The mass shrank to below the pupil and the perforation became closed by granulation tissue. Postmortem examination revealed that the iris stroma was completely replaced by the tumor mass.

Although the growth is slow in the early stages, affecting mobility over the involved area, it soon tends to advance rapidly invading the chamber angle; this may lead to increased intra-ocular pressure. Finally the mass may partly or entirely fill the anterior chamber, eventually invading the cornea. As a consequence of necrosis, a secondary iritis (although infrequent) may occur. If this should occur early when the nodule is small, confusion in diagnosis with a granulomatous lesion is conceivable, but the tendency to rapid growth and the history or suspicion of organic carcinoma elsewhere (especially the usual history of breast removal in women) will support the diagnosis of a carcinoma.


23 The Normal Lens - Biomicroscopic Appearance

The Lens

General Considerations. Biomicroscopic examination of no other part of the eye has been so fruitful and so rewarding as that of the lens. The use of the focal beam (especially the optic section) in the living eye has opened the door to new vistas in the development, morphology, and pathology of the lens, comparable to the advances following the discovery of the ophthalmoscope. Before the advent of biomicroscopy our concept of the living lens was inadequate as it was based for the most part only on what could be seen with the ophthalmoscope. Histologically, it was only by the employment of special staining methods (Rabl) that its fiber structure and suture systems became apparent. Ordinary methods of fixation and staining provide very little if any information concerning the actual structure, normal or pathologic, of the lens. The fixing and hardening histologic processes frequently make it impossible to cut the lens properly. With the ordinary hematoxylin and eosin staining the lens appears uniformly pink and it is often impossible to differentiate the normal morphology from the pathologic. Postmortem changes result in disintegration and vacuolization. The normal concentric (internal) zones of discontinuity and the suture systems, delicate changes like lamellary separations, water slits, vacuoles, opacities in the cortex, opacities of the inner nuclei, so beautifully seen biomicroscopically, are all unrecognizable as such in histologic preparations. However, it is possible to discern some of these delicate changes in the freshly removed lens. Such material is difficult to obtain and must be examined within a half hour after

948


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


949


death since vacuoles and degeneration of the fibers occur almost immediately afterward.

The normal lens continues to grow throughout life; biomicroscopically it presents different pictures with each epoch. The focused beam not only allows recognition of the developmental changes but topographicall)'" permits of their exact location. This holds true for pathologic and traumatic lesions as well. The lens consists of epithelial tissue only (except for its cuticular capsule) and grows by the transformation of its epithelial cells into fibers. The older fibers recede into the depths and become "hard” as the newer, soft fibers develop and grow around them. The progressive growth of the lens fibers from the earliest embryologic tissue results in a stratification of the internal architecture which ultimately forms the so-called zones of discontinuity (Fig. 350; Plate LVIII, figs, i, 2). These are zones in which there are sharp changes in indices of refraction, manifested biomicroscopically by stripes or bands of increased relucency. In optics such bands or stripes are known as zones of discontinuity (Vol. I, page 76; fig. 70) . In addition to these stripes definite systems of suture figures are seen. After the earliest embryonal stage the lens fibers grow from the equator toward the axial region of the lens. The meeting place of the fiber ends form the sutures. As will be shown later, this complex internal architecture of the growing lens seems not only to insure its development and maintenance, as an optical instrument of proper shape (its only purpose) but also to allow for the processes of accommodation. Before the advent of the biomicroscope, only the lens nucleus, the surrounding cortex, and the capsule were difierentiated. The Sanson-Purkinje reflex hinted at the presence of internal reflecting zones, but the exact internal architecture of the lens was unknown until after the invention of the biomicroscope.

For the purposes of orientation, the embryology of the lens will be reviewed briefly. Contrary to what occurs in other "epidermoidal”

According to Vogt, if lenses are fixed /« s//r/ by the mercury bichloride and platinum chloride method of Rabl, it is possible to examine fibers and their changes. However, even with this method one has to be careful in evaluating the findings because of secondary changes due to imbibitions and headings.


PLATE LVIII


Fig. I. Optic section through the normal lens. Anterior part is in focus; posterior parts seen in divergent (unfocused) rays. Observe zones of discontinuity, and the shagreens (specular reflex) of the capsule.

Fig. 2. Optic section through the normal lens. Posterior parts in focus, showing the band of the posterior adult nucleus, shagreen of the posterior lens capsule, remains of the hyaloid vessels, the retro-lental space (hyaloid vitreous). Anterior parts of lens now out of focus. Note the shadow from the small congenital opacity in the embryonal nucleus.

Fig. 3. Shagreen (specular reflex) of the anterior capsule and the anterior adult nuclear band. High power.

Fig. 4. Shagreen (specular reflex) of the posterior capsule and the posterior adult nucleus. Fligh power.

Fig. 5. Direct focal illumination. Showing composite view of the beam passing through the lens of a j'^oung man aged 17. Wide beam.

Fig. 6. Direct focal illumination. Narrow beam (optic section) through the lens shown in Figure j.


950


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


95 }


tissues (e.g., skin, nails, hair, etc.), the lens capsule prevents any shedding or casting oft* of early or "dead” tissue and hence throughout life it is possible to see even the parts which embryologically were present from the very beginning. After birth the rapidity of growth diminishes, the central or older parts become compressed or sclerosed as new or younger fibers grow around them. That the growth of new fibers is continuous during life was proved clinically by Vogt. In the case of the disseminated whitish cataractous spots seen subcapsularly after an acute attack of glaucoma it was noticed that after months or years these circumscribed spots were pushed into the deeper cortical layers. New clear fibers were interposed between these white spots and the capsule. In the "congenital” polar cataracts, separation of the opacity by clear fibers resulting in the formation of an imprint or duplication opacity is another instance of progressive growth of the outer part of the lens.

As early as the second week of embryonic life there is a slight elongation or thickening of the cells (lens plate) of the surface ectoderm where it lies in contact with the optic vesicle (Fig. 342). A depression of surface ectoderm of the lens plate soon follows and forms the lens pit. The pit deepens and the cells at the opening of the pit come together to form a stalk and a lens vesicle. During the fourth week (lo-mm. stage) the vesicle separates from the surface ectoderm and appears as a hollow globe or cyst, its walls being composed of a single layer of surface ectodermal cells. Anteriorly these cells become the subcapsular epithelium. The cells forming the posterior wall of the vesicle now begin to elongate (primary lens fibers) and grow forward until they fill the cavity of the vesicle. This process occurs during the fifth and sixth week, the embryo increasing in size to about 20 mm. at the end of the sixth week. At about the 1 3 -mm. stage a hyaline capsule is secreted. This comprises the posterior portion of the hyaline lens capsule. The anterior parts

According to the time of development of the lens nuclei before birth, I prefer to call the completed primary lens vesicle the "embryonic” one. Especially since the period of its growth occurs during the first three months of life when the developing individual is known as an embryo. For the same reason, the nucleus which starts to develop after the completion of this stage (i.e., after the third month or at the time when the developing individual becomes a fetus) is the "fetal nucleus."


954


BIOMICROSCOPY OF THE EYE


of the hyaline capsule are probably developed later, and peripherally some of the layers are derived from the lenticular expansions of the zonule, consequently the capsule is best developed in this region.


Fig. 342. Embrj'onal development of the lens. Stages in the development of the human lens. A, the lens plate; B, the lens pit; C, the lens pit closing; D, the lens vesicle; E, primary lens fibers complete; F, secondarj' lens fibers and sutures (After Mann )

Clinically, external portions of the hyaline capsule are seen in cases of exfoliation of the lens capsule (sende, glaucoma capsulare, heat cataract) The fact that the cells lining the posterior wall of the vesicle elongate explains the absence of epithelium on the posterior capsule. In extracapsular cataract operations the remaining thin transparent posterior hyaline capsule ordinarily does not interfere with vision but is easily visible biomicroscopically.

In the fully formed lens the elongated primary lens fibers that filled the primary vesicle are recognized biomicroscopically as a dark almost nonrelucent area in the center of the lens (the central dark interval) , the cellular outline of these cells no longer being apparent.

After this stage and during the rest of fetal life as well as the remainder of the life of the individual, new fibers (secondary fibers) are continuously derived from the cells of the anterior capsular

Employing special methods, Kolliker (1854),®**® Ivanoff/®' Berger/® and Schirmer, and Vogt (1914)®'*® demonstrated that the hyaline lens capsule consisted of numerous lamellae This was revealed by teased or macerated preparations or by the use of chemicals, acids and alkalies, salts and trypsin. Vogt was able to demonstrate ten layers.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 955


epithelium in the region of the equator. After the completion of the growth of the primary lens vesicle or embryonal nucleus, these fibers extend from the equator and grow around the primary ones


Fig. 343. Diagram of the course of the lens libers (human newborn). The erect anterior Y-suture is represented by solid black lines. The fibers are represented by grey lines, solid for the anterior zone and dotted for the posterior ones. All the fibers are of equal length. A fiber which originates from the posterior suture arm, Ef), ends at the center of the Y-suture, C. A fiber which originates from the middle of the anterior suture arm, Mp, ends at the middle of the posterior suture arm, Mb, A fiber originating from the outer third of the anterior suture arm, Ni>, ends at the inner third of the posterior arm, Nb, etc. (After Vogt.)


from all directions to form the two coffee-bean-shaped nuclei which after birth are located at a slight distance from the capsule. Between these nuclei is the dark interval (true embryonal nucleus) . The new nucleus contains the well known Y-sutures (recognizable at the 35mm. stage [8 to 9 weeks]) and is known as the inner embryonal (Vogt) or better as the fetal nucleus (Koby, Mawas and others). Its inner surfaces face the dark interval. The sutures, anteriorly an erect Y, posteriorly an inverted Y, are really potential spaces resulting from the line of contact or abutment of the fiber ends. (See Vol. I, Fig. 70; Figs. 343, 344 A and B, 36J, } 66 .) It is in these simple fetal sutures that the relations between the suture formation and fiber growth are best seen since in the more complicated many


956


BIOMICROSCOPY OF THE EYE

branched sutures (cortex and adult nucleus) it is not possible to trace the course of the fibers so easily. A fiber growing short (to form the extremity of one of the limits of the Y) anteriorly will


Fig. 344. Plastic representation of fiber growth in the formation of sutures.


grow longer posteriorly to end in the center of the suture (Fig. 343 ). A fiber growing to a point midway in the suture arm anteriorly will end correspondingly at the midpoint of the suture arm posteriorly. In this way it will be seen that fibers in one concentric zone are of the same length. This type of growth anteriorly and posteriorly insures the spheric development of the lens (Fig. 344). If all the fibers grew equally to meet in the center of the lens a discoid concavity would result at this place and the lens would have a to


958


BIOMICROSCOPY OF THE EYE

roidal shape; and hence would lose value as an optical instrument. At birth the Y-sutures are still close to the capsule (Fig. 345), but are already separated from it by a thin layer, the developing adolescent nucleus. From this point on during the remainder of the individual’s life It is this part of the lens in which development and growth of new fibers occurs. In young adults it already is possible to see the division in this part of the lens (anteriorly and posteriorly) into three main parts: (i) the adolescent nucleus; (2) the so-called "adult” nucleus; (3) the cortex, between the adult nucleus and the capsule (Fig. 346). In optic sections, lines of separation or disjunction are seen, i.e., lines immediately adjoining the capsule stripes. These lines (anterior and posterior) which are found even in the youngest individuals are closest to the capsule stripes in the polar regions but tend to diverge slightly (as do the other stripes) as they extend toward the equator. The importance of zonular traction in governing and maintaining the flatness of the lens postnatally is seen in the cases (microphakia and spherophakia, page 1341) in which aplasia of the zonular fibers occurs. In these cases lack of zonular traction results in a ball-like (spheric) lens. The action of the zonula may play a great role in length and branchings of the extrafetal sutures during life or at any rate until the time of presbyopia. With increase of lengthening and branching of the sutures (Vogt) the fibers that abut them have to become wider (they do this by becoming less thick) in axial regions in order to compensate for the greater area they have to occupy as compared with the region of their origin in the periphery. Likewise zonular traction and site of insertion of the zonular fibers may explain the lesser curvature (flattening of the anterior surface, which is a normal finding. The greater tension anteriorly (and hence the greater flattening) may be due to the more axialward insertion of the zonular fibers on this surface and to the diflerence in traction between them and the posterior zonular fibers.

Blood Supply. In fetal life - for the purpose of nourishment - a vascular net derived from branches of the hyaloid vascular system in the vitreous forms on the posterior capsule (posterior vascular cap


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


959


sule) . From this net parallel vessels (capsulopupillary portion) run anteriorly around the lens equator or between it and the margin of the optic cup. These vessels anastomose with the annular vessel (cho


Fig. 347. Diagram of vascular capsule of the lens. A, anterior part (pupillary membrane) ; B, Capsulopupillary part; C, Vasa hyloidea propria and posterior vascular capsule; D, Hyaloid artery. (After Mann.)


roidal veins) . Both are seen by the i6-mm. stage and reach their maximum development by the 40- or 50-mm. stage when regression occurs. At about the 2 8 -mm. stage branches from the capsulopupillary vessels and from the long ciliary vessels form a series of loops which cover the anterior capsule of the lens (Fig. 347) . These form the anterior vascular capsule and the pupillary membrane. (See chapter on Iris, page 755.) At the 4 8 -mm. stage the more developed peripheral parts lose their connections with the capsulopupillary vessels at the time the ectodermal part of the iris begins to extend forward. By the seventh month marked regression and atrophy of the posterior, lateral (capsulopupillary) vessels has occurred and beginning atrophy of the anterior vascular capsule is noted. However, the arcades of the central portion (pupillary membrane) do not disappear until almost term. The peripheral system which loses its connection with

According to Terry, the term "lateral or capsulopupillary" for a portion of the tunica vasculosa lentis is confusing. He suggested the term "intermediary portion” of the tunica vasculosa lentis as more suitable.


960


BIOMICROSCOPY OF THE EYE


the capsulopupillary vessel persists to form the deeper vessels vascularizing the iris stroma. Although grossly there appears to be a complete atrophy of all the vascular capsule of the lens the biomicroscope has revealed that this is not so. In every eye vestiges of the hyaloid system (tunica vasculosa lentis) are observed not only on the posterior lens capsule but also in the anterior parts (hyaloid or retrolental) of the vitreous. This is demonstrated by the universal presence of the small hyaloid remains (corkscrew remnant) , the arcuate hne and occasionally the presence of nodular circumscribed whitish bodies, the so-called spurious posterior polar cataracts, which Vogt designated as corpusculum nodularis hyaloidea,” on the posterior lens capsule (Figs. 373, 374). Anteriorly, in about 25 per cent of normal people (according to Mann) there are tags of the pupillary membrane attached to the lesser circle of the iris. Not infrequently a central attachment to the lens capsule occurs. A large number of lenticular anomalies may be due to or connected with the persistence of pupillary membranes. Not uncommonly, we find pigmented or whitish starlike remains, threads (white or pigmented), or small white thickenings on the anterior capsule (Vol. I, Plate XXXVIII). In addition (with dilated pupil) fine radial lines or stripes are seen occasionally peripherally on the anterior capsule. These are known as retro-iridal lines or stripes, and they probably represent remains of the capsulopupillary vascular membranes or, as Vogt prefers to call them, the “tunica retro-iridalis” since in the histologic sense they are not true membranes.

Technique of Biomicroscopy of the Lens

With the obvious exception of sclerotic scatter, all the methods of illumination applicable to the cornea are employed in the examination of the lens. (See Vol. I, Chapter Three.) These are:

1. Diffuse illumination

2. Direct focal illumination (wide and narrow beam)

3. Specular reflection

4. Retro-illumination


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


961


5. Indirect illumination

6. Diapupillar)'’ transillumination of the lens in fundal reflex (transillumination of the lens by means of light reflected from the fundus)

With the undilated pupil only the axial regions of the lens are accessible. Unquestionably it is impossible to make an accurate survey of the lens unless the pupil is maximally dilated since a large percentage of lens changes either begin or are localized in the periphery. The examination room should be dark, and the observer darkadapted. The light should be directed first from the temporal side and then from the nasal in order to view both medial and lateral portions of the periphery. Even with the pupil maximally dilated, e.g., as obtained by the use of a cotton pledget soaked in 1:1000 epinephrine or 10 per cent neosynephrine, it is impossible to see the actual equator or the zonule. This is only possible with coloboma irides or subluxated lens, or when a condition such as spherophakia is present. However, by directing the patient’s gaze upward, downward, and sideways it is feasible to examine most of the lens.

J

DIFFUSE (AFOCAL) LIGHT

When one employs the pre- or postfocal part of the beam (Vol. I, page 69) for illumination of the lens it is possible with sharp focusing of the microscope to see certain surface areas in their entirety (Fig. 348). For example, the anterior lens surface with part of its shagreen, the surface and suture system of the adult nucleus (only in older individuals), the entire embryonic Y-sutures and the posterior capsule (especially when altered pathologically). This method corresponds to the ordinary method of oblique examination with the loupe and lens except for the fact that observation of details is aided by the use of the binocular microscope. Using a condensing lens and loupe Tscherning®^^ noted the now well known bright "image” within the pupil. When the light is bright the pupil appears white (in a normal lens) as if a mature cataract was present. This image results partly from specular reflection (shagreen) of the cap


962


BIOMICROSCOPY OF THE EYE


sule and surface of the adult nucleus. With the loupe especially in older persons the suture system of the adult nucleus can be made out. Using the unfocused part of the beam together with the microscope


â– *.

t


Fig. 348. Diagram illustrating technique of diffuse illumination.


such details can be seen more distinctly. The entire extent of the posterior Y-suture and certain types of localized lens changes, such as congenital cataracts, polar cataracts, lenticonus, saucer cataracts, can readily be seen “en pleine.” However, this method does not allow for accurate localization except as one judges it by focusing the microscope, using known fixed points of reference, e.g., the anterior or posterior lens capsule.

DIRECT FOCAL ILLUMINATION

If the focused beam is allowed to pass diagonally into the pupillary opening it will be seen, that similar to the appearance in the cornea (but unlike the anterior chamber which normally appears dark) a


Fig, 349. Diagram illustrating direct focal illumination. Anterior parts of the lens in the focal part of the beam. Posterior parts of the lens in the post focal of the beam. The prefocal part of the beam is located in the cornea.


will show the Tyndall phenomenon in varying degrees (Vol. I, page 72), depending not only on the intensity of the light but also on tissue density. As the light passes through the cornea and forms the parallelepiped, a proportional amount of the light’s intensity is "used up” and this in itself tends partly to weaken the apparent relucency of the lens block. The illuminated lens segment or "phantom,” which optically represents a section through the lens thickness, is the visible manifestation of its optical properties (Fig. 349). In summation, these are refraction, reflection from the surfaces (zones of discontinuity) of its layers, internal dispersion, polarization and fluorescence. At each stratum in the lens where a difference


964


BIOMICROSCOPY OF THE EYE


in index of refraction abruptly occurs we become aware of a zone or band of increased brightness. As the light passes through the lens posterior ward it will be seen that there are about six main whitish


Fig. 350. A. Diagram showing passage of the beam L from left to right through the lens and the illumination of the major zones of discontinuity. These are, in order, i, capsule stripe; 2, surface of the adult nucleus; 3, anterior fetal nucleus; 4, posterior fetal nucleus; 5, surface of the posterior adult nucleus; 6, the posterior capsule. The fainter adolescent stripes between the adult and fetal nuclei are not shown. B. Diagram illustrating the central fetal nuclei surrounded by the adult nuclei which in turn is surrounded by the cortex.


stripes or zones of discontinuity (Fig. 350 A, B). The width of the bands or stripes depends on the width of the beam. Between them lie darker areas. On the two central stripes the anterior and posterior fetal Y-sutures are seen. It should be pointed out that although these stripes are represented in drawings as thin layers, actually they have some thickness. Beginners frequently make the error of interpreting the zones of discontinuity as running in a sagittal direction while actually they are concentric to one another. In contrast, the sutures extend sagittally at right angles to the zones of discontinuity.

These zones of discontinuity result from and represent the internal architecture of the lens. It should be remembered that owing to the fact that the sagittal diameter of the lens is from four to five times that of the cornea, it is not possible to keep its entire thickness within the focal part of the beam at one time, nor is it possible to observe all its parts sagittally with one focus of the microscope. Also


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


965


when the focused part of the beam is situated at the anterior portion of the lens (capsule) , the deeper or the posterior parts are viewed in diverging (postfocal) rays (Plate LVIII, figs, i, 2). Consequently the beam must be refocused deeper in order to reveal details in this area. To bring out clearly the reflecting surfaces (zones of discontinuity) it is necessary to have the beam as sharply focused as possible at the exact point where these sudden differences in index of refraction occur. Hence, both the beam and the microscope must be successively refocused ever so slightly as one proceeds from the anterior surface to the posterior surface of the lens. To a large degree, with an illuminating lens of 100 mm. (the one commonly used is 70 mm.) a beam of greater length is obtained, although the focal part of the beam is less luminous. Some of this refocusing is obviated if one of the diaphragms (Poser slit-lamp equipment) is used. This gives an increase in length to the focal part of the beam and with low power one can almost visualize the entire sagittal thickness of lens (without successive refocusing) .

Wide Beam. Ordinarily the width of the slit opening governs the width of the focal part of the beam; narrowing the slit opening results in a corresponding decrease in width of the focal part of the beam and a proportional decrease in its light intensity. With the slit aperture wide open the beam' attains its greatest luminous intensity and forms the so-called "broad beam.” (See Vol. I, Fig. 66). As this passes through the cornea it forms the "parallelepiped.” When the broad beam (slit opening from 2 mm. to i mm.) is focused on the anterior capsule of the lens, a sort of parallelepiped forms in the anterior part of the lens - the anterior surface representing a portion of the anterior capsule of the lens, the posterior surface of the parallelepiped representing a portion of the surface of the adult nucleus, while the intervening thickness represents the anterior cortex (Fig. 397). From here on the beam (post-focal part) diverges somewhat and illuminates the deeper layers in a diffuse manner. As is the case in the cornea, finer details of tissue stratification and the ability of exact localization are lost owing to reflection and diffusion. In other words the wider the beam, the


966


BIOMICROSCOPY OF THE EYE


wider the area of illumination of the discontinuity surfaces will result, and consequently interference with observation of the intervening structures will occur. Also see Plate LVIII, figs. 5, 6.

Narrow Beam. For the greatest single advance in biomicroscopy we are indebted to Vogt who showed that it is possible to narrow a beam without any loss of sharpness. Not only does the narrow beam permit us to see the finer stratification of the topography of the normal lens structure (zones of discontinuity), which was previously unsuspected, but it also facilitates exact localization of even the most minute changes. The knowledge gained by this method of illumination of the lens has revolutionized our concepts of its morphology and pathology. It is only by means of the optic section that we are able to see the normal zones of discontinuity sharply. These zones represent lenticular growth epochs; this has made it possible for us to determine the chronologic age or time of origin of opacities in many instances. For example, it is now possible at a glance to identify and to differentiate between congenital, acquired opacities, presenile and senile changes, traumatic opacities, complicated opacities in ocular disease, opacities due to exogenous toxins, etc. When stud^dng the lens the beginner should make it a practice first to direct the moderately wide beam (i mm.) through its substance and then to practice narrowing the slit (it can be narrowed down to from o. j to o.i mm.) , while observing the changing appearances through the microscope. As the slit narrows, the brighter bands or stripes (the zones of discontinuity) become increasingly visible despite the lowered luminosity of the beam. These stripes are the optical delineations of the surfaces of the nuclei at which the index of refraction changes sharply. They are seen at birth and throughout life. Thus, as Vogt has indicated a confmnous variation in index of refraction, previously thought to occur in the lens in early life, does not exist.

When the beam is narrowed marked^, the stripes appear as lines and the less relucent spaces beween them represent sections through the sagittal thicknesses of the "nuclei” (Fig. 351). As previousl}^ mentioned, with the pupil dilated to the maximum, the narrow beam


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 967

should be directed into the lens from the nasal side as well as from the temporal in order to traverse as much lenticular substance as possible, always bearing in mind the necessity of sharp refocusing


Fig. 351. Projection of the narrow beam (optic section) through the lens, showing zones of

discontinuit)' ( 1 - 12 ). (Diagrammatic.)

of both beam and microscope as deeper portions of the lens are scrutinized.

One first focuses the microscope at the point of impact (anterior lens capsule), where the beam strikes the lens; then both microscope and beam are gradually and concomitantly focused deeper, always so that the focal part of the beam and the focus of the microscope fall at the same point in the lens. This process is continued until the entire thickness of the lens is traversed and the posterior capsule comes finally into view. When the anterior capsule is in sharp focus, it will be seen that the deeper portions of the lens are traversed by divergent rays, and consequently the height of the lens block is greater posteriorly than anteriorly. When the beam is sharply focused on the posterior capsule, the converse is true. Behind the posterior capsule the gossamer structure of the vitreous is seen. After the anterior and posterior capsules have each been brought into focus, then one begins to differentiate the internal zones of discontinuity and their markings (sutures) . By shifting the beam slowly from side to side and by changing the direction of the illumination from


Fig. 352. A. Diagram showing technique of retro-illumination. I, incident beam; O, observation. Small subcapsular vacuoles are viewed in the light reflected from the deeper parts of the lens. B. Actual appearance of subcapsular vacuoles by retro-illumination. The two laterallylocated vacuoles illustrate unreversed illumination. C. Actual appearance of vacuoles in direct focal illumination. Note shagreen area of the anterior lens capsule.


968


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 969


the temporal to the nasal or vice versa, one obtains sagittal "serial sections” of the lens. This is repeated superiorly and inferiorly to cover the entire exposed extent of the lens insofar as the pupillary diameter permits. In the peripheral areas it will be noticed that the zones of discontinuity are not exactly concentric but tend to diverge from each other owing to the greater curvature of the internal nuclei as compared to the curvature of the capsule.

RETRO-ILLUMINATION

By employing light reflected from the deeper portion of the lens as the focused beam passes through it obliquely, it is possible to view alterations situated more anteriorly and to one side of the beam (Fig. 352), Especially valuable as a source for retro-illumination is the light obtained by specular reflection from the posterior capsule. Although small in area, its brightness is of great advantage. Owing to the yellow color of this reflex, changes seen anterior to it will have a yellowish tinge (Fig. 353). The use of retro-illumination is very valuable for viewing anterior capsular changes, such as deposits or foreign bodies, opacities, spokes, and also vacuoles below the capsule (Fig. 352 A, B; Plate LXVII, figs. 3, 4). In opacifications of the posterior capsule and posterior cortex, e. g., posterior cupuliform cataract (saucer-shaped), the involved layers act as reflection screens. This corresponds to the use of an opaque pupil (cataract or membrane) for retro-illumination of the cornea.

Remains of the pupillary membrane (threads or stars), whether pigmented or not, are also well outlined by retro-illumination (although they are seen best by direct focal illumination) . By their shape and ultimate connection to the lesser iris circle, they usually can be differentiated from pathologic deposits of pigment or exudate on the anterior lens capsule. In severe plastic iritis, vessels from the iris may cross the anterior lens capsule. Retro-illumination will bring out the red color of tiny capillaries if they contain blood. Such vessels might appear as gray lines by direct focal illumination.

The optical effects produced b) this method will depend on the character of the alteration viewed; that is, whether the detail observed in retro-illumination is (i) obstructive (opaque to light), (2) respersive (scatters light), or (3) refractile - refracts, minimizes, or distorts the views of the background. Also the optical



Fig. 353. Retro-illumination of the lens. Method employing the small brilliant zone of specular reflex of the posterior lens capsule as a reflecting surface. 7 , incident beam; R, Retroreflected specular rays; op, opacity; O, direction of observation. (Diagrammatic.)

effects projected by certain observed details will vary depending on whether they are observed by direct retro-illumination or indirect retro-illumination. (See Vol I, Fig. 85; also Fig. 352 B.) For example, a vacuole viewed by direct retro-illumination will have a light center surrounded by a dark border. By indirect retroillumination the vacuoles display unreversed illumination, that is, only the margin of the vacuole nearest the light is outlined by a bright crescent of light. Solid or opaque features reveal reversed illumination, that is, their side or edge away from the light will be brighter. Generally speaking, direct retro-illumination is most See Volume I, Chapter III, pages 83-91.


useful in observing structures that obstruct or refract light, while indirect retro-illumination is recommended for the study of structures that are refractile or respersive. In this way one may gain information not only concerning the form of structures but also about their refractive index as compared with the refractive index of the adjacent media.


SPECULAR REFLECTION

The smooth glossy surfaces of the lens capsule and nuclei act like mirrors and as such reflect incident light both regularly and irregularly (Vol. I, page 91). Similar to the cornea, when the eye of the observer is in the path of the regularly reflected rays (the angle of incident being equal to the angle of reflection) and is focused exactly on the surface, the place where this phenomenon occurs becomes visible (zone of specular reflection) . The fact that we are able to discern not only the zones of discontinuity but also mirror reflecting zones on the surfaces of the inner nuclei of the lens as well as from the capsule proves, as already indicated that no uniformly gradual change in index of refraction occurs. Rather there are sudden changes, as indicated by the presence of zones of discontinuity (also called "bands”) and their mirror reflexes. According to Vogt, the old opinion that the index of refraction in the lens changes during life in only one zone of discontinuity, is not borne out by factual evidence disclosed by the biomicroscope.

Mirror Reflexes of the Anterior and Posterior Capsule. As the beam is moved from side to side across the surface of the lens, a bright reflex (the shagreen) is visible (Plate LVIII, fig. i, 2). Its glittering design is suggestive of beaten silver. Optically the design seen in the shagreen is due to the irregular reflection caused by small irregularities of the capsular surface. The detail of the shagreen of the anterior surface of the lens does not represent the actual lens epithelium and is not comparable to the posterior corneal surface where it is possible to see in the specular reflex the outlines of the endothelium. Actually, the lens epithelial cells can be seen with difiiculty under high power in the central portion of the specular reflex as much smaller dots in the design of the shagreen (Fig. 354) . Vogt has suggested that this difiiculty in focusing the epithelium sharply may be due to the fact that reflections from the overlying


Fig. 354. Shagreen area (specular reflex) of the anterior lens capsule. Small dots probably represent reflections from the underlying epithelium (high power).


capsule cause interference. Also, the difference in index of refraction between the hyaline capsule and its underlying epithelium, as well as between epithelium and cortex, seems to be less than that between cornea and aqueous.

The epithelial cells also appear as small grooves or prominences and are best seen especially over the dark background of an underlying cortical water slit. According to Gullstrand and Vogt, the capsule, epithelium, and the superficial lens fibers with the system of lens sutures probably all contribute in the formation of the anterior shagreen. They emphasized this point because when focusing the shagreen it is possible at times to make out dark suture lines and a radial fiber design. In my opinion the reason for the appearance of the suture lines and radial fiber design in the shagreen is not that they actually go to make up the shagreen of the capsular surfaces but that when we focus the capsule shagreen, we may at the same time get internal specularity from the subcapsular layer. In other words through the capsular shagreen we see specular reflection from the underlying surfaces. This is similar to the occurrence in the cornea of intrinsic specularity (Vol. I, page 103). Also one can easily be convinced on this point because after focusing the capsular shagreen, it always requires a minute shift in angulation between illumination and observation to bring out the suture and fiber design more clearly within it.

Consequently I agree with Butler who also considers that the anterior and posterior shagreens belong to and define the surface of the hyaline capsule. He pointed out that (i) the presence of a shagreen on the posterior capsule where the epithelium is absent indicates that it is not a necessary requirement in its formation; (2) the shagreen is present even in morgagnian cataract where the adjacent fibers are liquefied - this would tend to rule them out as a necessary component in the formation of the shagreen; and (3) in glassblowers cataract and exfoliation of the anterior layers of the hyaline capsule it is possible to observe the shagreen on the detached capsular lamellae.

As was shown in Vol. I, Chapter II, page ^3, defects, such as deposits or opacities, elevations or depressions, may interfere with the specularly reflected rays and may appear as dark spots in the plane of the bright specular area.

The shagreen area of the anterior lens capsule appears as a sharply limited zone occupying only a small part of the entire length of the surface of the opalescent lens block at any one time (Plate LVIII, fig. 3 ) . Its width is directly proportional to the width of the slit opening. When the angle of the beam and axis of observation are so arranged that the specular reflex is not present at the point of capsular illumination, the surface of the lens block is seen by a somewhat diffused light and consequently appears gray and opalescent. If the unfocused beam (pre- or postfocal) is employed, the edges of the shagreen area are unsharp and show a gradual transition into the neighboring areas. By having the patient look slowly to the temporal side, it will be seen that the shagreen area moves to the nasal side and vice versa; if the gaze is slowly directed nasally, the temporal side of the anterior lens surface shagreen area becomes visible. The opposite maneuver holds true for the brighter, smaller, and yellower zone of specular reflection from the posterior capsule which actually is an inverted image. Because of the greater curvature of the posterior surface of the lens, the amount of specularly reflected rays from this surface at any one given point is smaller than that from the anterior surface. This accounts for the fact that the specular reflex of the posterior surface is always smaller than that from the anterior. Because the shagreen areas accurately define the capsular surface itself, they may be used as planes of reference for the purposes of localization when employing the wide beam (see traumatic cataract page 1244), e.g., in determining whether a lesion is capsular or subcapsular. Even when employing the narrowest possible beam and high power it may at times be difficult to decide whether an alteration is directly on the surface of the capsule, within its hyaline substance or even just beneath it, i.e., in the epithelium. If the alteration produces a defect (a dark or shagreen-free area) in the shagreen field, it definitely must be on/in the actual surface of the capsule.


The word "shagreen" (F. chagrin) was adopted because of its fancied resemblance to shagreen leather, the surface of which is granular. Personally, I feel that the normal anterior zone of specular reflections of the lens more closely resemble the appearance of "beaten silver" and that the brighter and yellower reflex of the posterior lens surface simulates "beaten gold".


Mirror Reflexes {Zones of Specular Reflection) of the Anterior and Posterior Adult Nuclear Sti-rfaces. Owing to the greater curvature of the adult nuclear surfaces these reflexes are necessarily smaller. Also since these surfaces become more reflecting with age, they are seen more easily in adults than in the young. Both anterior and posterior nuclear reflexes are less bright and yellower in color than the capsular reflexes (Plate LVIII, figs, i, 2, 3, 4). This yellow color, especially in the case of the reflex of the posterior adult nucleus, tends to become more orange or reddish with age. 'Since the posterior capsular reflex is always more yellow, the reddish tinge of the reflex of the posterior adult nucleus cannot be entirely caused by the physiologic increase in yellowness of the nucleus during age. In both these cases, the light filters through the yellow nucleus twice - on its way into the lens and on its passage back. The difference in color between these two posterior specular reflexes is probably due to differences of intensity of reflection as well as to "selective” reflection (Vogt) owing to the special physical structure of the zones of discontinuity. In order to see the zone of specular reflection of the anterior surface of the adult nucleus, one first focuses the specular reflex of the anterior surface of the lens. At any given point, when this is in focus, the reflection from the surface of the adult nucleus will not be seen. In other words it is impossible to see both in the same visual axis since the curvature of the anterior adult nuclear surface is greater than that of the anterior surface of the lens. In order to see the reflex from the surface of the adult nucleus when one looks through the microscope, it will be necessary either to change the direction of the observation or to have the patient change his direction of gaze - say, slightly toward axis of illumination. Since the direction of the light beam is usually from the temporal side (we see the specular reflex of the anterior lens surface in the temporal region), the reflex from the surface of the adult nucleus comes into view as the patient turns his gaze slightly temporally. The rays specularly reflected from one given point enter only one objective of the microscope at a time. By closing one eye the observer can, with proper angulation of the beam and the microscope, see the specular reflex of the anterior surface of the lens in one ocular; then by closing the other see the specular reflex from the surface of the adult nucleus. In each case only one reflex will be seen in a single ocular.

BIOMICROSCOPIC APPEARANCES OF THE NORMAL LENS

As mentioned on page 964 the passage of the focused beam through the lens discloses well-defined relucent stripes or zones of discontinuity. These zones are best seen with the narrow beam and exact focusing of the microscope.

For the purposes of description, the zones of discontinuity of an adult lens (as seen with the optic section) from before backward (Fig. 355) may be enumerated as follows: (i) anterior capsular stripe; (2) anterior line or stripe of disjunction; the intervening


976


BIOMICROSCOPY OF THE EYE


layer between this stripe and the next consecutive one (adult nucleus stripe) representing the anterior cortex; (3) anterior stripe of the adult nucleus; (4) anterior outer stripe of the fetal nucleus (outer


Fig. 355. View of the zones of discontinuity in the lens (left to right, i-io) as seen by means

of the optic section. (Diagrammatic.)


embryonal stripe of Vogt) (5) anterior inner stripe of the fetal nucleus; the dark central interval (the truly embryonal part of the lens) : (6) posterior inner stripe of the fetal nucleus; (7) posterior outer stripe of the fetal nucleus; (8) posterior stripe of the adult nucleus; the posterior cortex: (9) posterior linear stripe of disjunction and (10) posterior capsular stripe.

The biomicroscope not only permits observation of these stripes and intervening areas but also their characteristic markings, such as their zones of specular reflection which differ one from the other

Occasionally additional stripes located between 3 and 4 and between 7 and 8 are seen. I have designated them as adolescent. See Fig. 364.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


977


as regards size and color, their suture systems, and, on the posterior capsule, the remains of the hyaloid vessels and canal.

It will be recognized that each stripe represents optically a section through a zone of discontinuity or place where a sudden change in the index of refraction occurs. Since we assume (and with good reason) that these zones, especially the internal ones, represent areas corresponding to the nuclear surfaces, then the less relucent areas lying between these zones represent sagittal sections through the thickness of the nuclei. The dark interval, the most homogeneous and least relucent part of the lens formed in embryonal life from fibers developed from the epithelium of the posterior part of the lens vesicle (embryonic nucleus), therefore lies within the fetal nuclei. This tends to divide the lens equatorially into an anterior half and a posterior half. Clinically, the dark interval may be a place of lesser resistance as evidenced by the occasional appearance of two nuclei in extracapsular cataract extraction. In addition, in biomicroscopy (of) nuclear cataracts, the middle part of the dark central interval may remain uninvolved leading to the so-called "lens of double focus” (page 1 1 50) . The curvature of the posterior capsule, as is well known, is. greater than that of the anterior capsule. Correspondingly, the curvature of the posterior stripes is greater than that of the anterior. The radii of curvature of the stripes decreases as the center of the lens is approached. Hence the curvature of the stripes increases the closer they are to the central interval. Also the stripes are not concentric to one another, owing to the fact that the distance between them is less in the axial region and gradually widens toward the equatorial regions. This results in what Vogt has termed a peripheral divergence, an arrangement which, in association with the progressive lengthening of the suture systems, causes the growing lens to become less spherical or flatter. Actually the divergence of the zones of discontinuity in the lens periphery is caused by the fact that as the zonule becomes tense, the cortical sutures become longer and the caliber of the individual radial lens fibers making up the nuclei between the zones of discontinuity, especially of the soft cortex, are thicker sagitally in the periphery than in the axial regions.


978


BIOMICROSCOPY OF THE EYE


Evidently the zones of discontinuity form in consequence of the growth of the lens and biomicroscopically leave indelible signs of this growth from the earliest embryonal beginnings until death. The exact rhythm of lens growth and formation of the zones of discontinuity is still unknown. It may be that the zones of discontinuity are expressive of transient inhibitions in the rhythm of lens growth. The middle part of the lens (fetal portion) is the oldest. The peripheral portions, which grow around this central portion, develop chiefly after birth; hence the youngest portions are those subcapsular (anterior parts of the anterior cortex and the' deepest parts of the posterior cortex) . Even in infants where the fetal (Y) sutures are closely subcapsular, lens substance between the sutures and the line of disjunction is already to be seen. This is the earliest indication of the so-called future adult nucleus and cortex, the surfaces of which become increasingly more reflective with age (page 1019) . As already mentioned the biomicroscope permits us to see at a glance the "life history” of the lens and by using the zones of discontinuity as reference points not only to localize the position of normal and pathologic changes but also to determine at what period in the "life history” of the lens they formed. For example, just before birth the lens consists of the central (fetal and embryonic) nuclei surrounded by the capsule. The greater part seen later between the fetal nucleus and the capsule has of necessity grown in after birth. So it is easily understood that congenital opacities will have to be found within or near the central nuclei (embryonic and fetal) or connected to or in the vicinity of the lens capsule (polar cataracts) since these were the only parts of the lens extant during embryonic and fetal life. With certain exceptions (e.g., nuclear cataract, which appears to start in the fetal nucleus) , changes seen developing outside the central nuclei ordinarily cannot be considered as congenital in origin, although they may be hereditary (abiotrophic) in character. An instance of this is seen in the case of coronary cataracts, undoubtedly genetically determined, which appear after

In an infant aged tw'O months there already was a small amount of lens substance befw’een the capsule and the surface of the anterior fetal nucleus.


THE normal LENS; BIOMICROSCOPIC APPEARANCE 979

birth outside the adult nuclei. Also, as Vogt has shown, particularly in his studies of uniovular twins, certain presenile and senile lens changes leading to cataracts appear with such exactitude of form, location and- time in each twin that it is certainly beyond the realm of chance or coincidence.

The exact significance of the zones of discontinuity is not known. Together with the pulling effect of the zonule, the suture systems and the zones of discontinuity are probably the philogenetic expression of a mechanism intended to insure the “flatness” of the lens shape; to permit it eflSciently to perform its function of accommodation. It well may be that the zones of discontinuity result from changes in metabolism, or from sudden spurts or retardation in growth rhythm. The avascular lens has an auto-oxidativc system, receiving its nutrition via the capsule from the surrounding fluids. Perhaps during certain epochal periods as new young fibers develop, the metabolic rate in the older and deeper fibers degrades to a lower order resulting in physical and chemical variations sufficient to cause a change in their index of refraction. It is also conceivable that toxins might cause a similar change in the growing parts of the lens. Koby states: "An interesting phenomenon is the appearance of accessory bands (zones of discontinuity) usually in the deep cortex, and in certain cases we have been forcibly impressed that these bands (stripes) were brought on by endocrine disturbance.”

The fact that there were reflecting layers in the lens was demonstrated years ago by the Sanson-Purkinje images (regular reflection) . Since with the biomicroscope we now are able to see the details of the zones of discontinuity or the actual places where the reflex forms, we are no longer interested in mere optical imagery. Using a wide beam without the binocular microscope, Gullstrand was the first to describe the zones of discontinuity. Vogt (1917- 1918), who discovered the value of the narrow beam (optic section), was able to describe these xorres with greater accuracy. By means of the optic section he first showed the presence of the embryonal nuclei (embryonal and fetal, according to later terminology) and the markings (suture lines, hyaloid vessel remnants) on the other zones


980


BIOMICROSCOPY OF THE EYE


of discontinuity (capsule and adult nucleus) . In the latter part of the last century several workers noticed two small grayish reflecting zones in the vicinity of the Sanson-Purkinje reflexes which they cor


Fig. 356. Diagram showing technique of retro-illumination by means of light reflected from the fundus. I, incident light; O, angle of observation. Certain changes in the pupillary border of the iris and lens will have a red glow when viewed in this light.


rectly referred to as the surfaces of the nucleus (adult). This was corroborated later by v. Hess who showed that these were physiologic in the aged and called them the anterior and posterior miniature nuclear pictures. However, as Vogt has pointed out, the descriptions by V. Hess and even by Gullstrand of the stripe of the adult nucleus show that in reality what they saw was the posterior fetal nuclear surface."'

'■= Gullstrand,^®^ in speaking of the zones of discontinuity referred to them as the "Hess nuclear pictures.” According to von Hess, the distance of the second maxima (the first


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


981


RETRO-ILLUMINATION OF THE LENS BY MEANS OF LIGHT REFLECTED FROM THE FUNDUS

Under certain special conditions, i.e., close approximation of the axes of observation and illumination or better observation along the


Fig. 357. Appearance of red glow from fundus when the angle of observation almost coincides with the axes of the emergent rays from the fundus.

beam axis with the unaided eye, it is possible to view certain changes in the lens by means of the red glow reflected from the fundus oculi (Figs. 356, 357). Thus, e.g., it is feasible to retro-illuminate the contents of a "spoke” in the cortex. This method corresponds to the old technique employed in ophthalmoscopic scrutiny of lenticular opacities in the light reflected from the fundus. Application of this

was the surface of the adult nucleus) from the posterior surface of the lens appears to be about two or three times the distance between that of the first maxima and the anterior capsule. In reality this would place the second maxima in the region of the surface of the posterior embryonal nucleus. Von Hess was not aware of the fetal or embryonal nuclear surfaces. As Vogt has said, Gullstrand just had to make this error because he did not know of the principal of narrowing the beam, especially since the surface of the posterior embrj'onal layer is the most strongly refractive layer of all the posterior zones of discontinuity.


9S2


BIOMICROSCOPY OF THE EYE


method has been referred to already in the section on the iris and will be dealt with again (page 1317).

ANTERIOR CAPSULE STRIPE

As we observe the passage of the focused beam into the lens through a moderately dilated pupil, we see an illuminated oblique sagittal section extending through its thickness (Vol. I, Fig. 66). This illuminated portion is known as the lens block or "phantom” (Koby) and is the optical expression of the Tyndall phenomenon in the lens. The term, optic section, is reserved for the "phantom” obtained by the narrow beam (Vol. I, Fig. 70) . As is the case in the cornea the width and height of the illuminated section depends on the width and height of the diaphragm opening. As the width of the slit opening is narrowed, the width of the section decreases with a corresponding lowering of its brightness. The lens area surrounding the illuminated block or optic section is dark. The contrast between the illuminated section and the adjacent dark areas is of great importance in emphasizing the visibility of microscopic details. An analogous phenomenon is seen in the dark-field type of microscopic illumination. (Also see Plate LVIII.)

The line of impact of the block or section represents the illuminated portion of the anterior capsule. With the very narrow beam this becomes converted into a line of illumination. Consequently when studying the surface of the anterior capsule the wider beam gives a larger surface area of illumination. As the beam is moved horizontally across the pupillary area, the surface of the lens block (anterior capsule stripe) appears uniformly opalescent â– â– â– until the normal anterior mirror region (zone of specular reflection) is met. This occurs when the direction of the light and observation (angle of incidence equalling the angle of reflection) , is so placed that the observer is in a position to perceive the rays regularly reflected.

^ In older persons, frequent!)" a delicate whitish moire-like (water markings) design is seen on the surface of the anterior capsule. It takes the form of barely visible irregularly coursing lines. Whether this is related to the more marked flocculent desquamation of the zonular lamellae seen in age as well as in glaucoma capsulare is not known.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


983


Then rather suddenly, the bright beaten-silver appearance is seen (shagreen) . This mirror region occupies only a small part of the length of the anterior capsular stripe even with the wide beam, but its width extends across the full horizontal extent. Hence the lateral edges of the mirror zone are sharp, corresponding to the sharp borders of the broad capsule stripe. If the unfocused beam, pre- or postfocal (corresponding to diffuse illumination), is employed, then the lateral margins of the shagreen picture show a gradual transition into the adjoining non specular areas. Owing to the fact that we are looking at zones of specular reflection from curved surfaces, the size of the mirror area will depend on the radius of curvature of the reflecting surface. The shorter the radius (greater the curvature) the less will be the number of specularly reflected rays projected into the observer’s eye at any one point. The smaller size of the shagreen area of the more curved posterior capsule is an illustration of this.’’* However, the smaller mirror zone of the posterior capsule is more brilliant than is that of the larger anterior one.

DETAILS OF ANTERIOR MIRROR ZONE (ANTERIOR ZONES OF

discontinuity)

Shagreen. Examining the mirror area in sharp focus the coarse design (made up of grooves and prominences) is easily apparent even with lowest powers of magnification (Fig. 354). Unlike that which is seen in the zone of specular reflection of the posterior corneal surface where the outlines of the endothelial cells are perceived, in the lens this larger design is not caused by the outlines of the capsular epithelium but rather by defects in the surface of the hyaline capsule itself. Using the pre- or postfocal part of the beam or weakening the light of the wide beam and studying the anterior shagreen fields in the axial regions of the lens, it is possible to see in them portions of the sutures and a distinct radial fiber design (page

In animals where radii of curvature of the lens surfaces are greater (spheroid type of lens) the zones of specular reflection are smaller than in the flatter lens of man. Following an iridectomy in a 58-year-old woman who was using pilocarpine-eserine mixture, Vogt found that the shagreen field became as small as that seen in a rabbit (spheroid lens). Evidently a relaxation of the zonule and with it an increase in the curvature of the lens surface occurred, owing to ciliary muscle spasm.


984


BIOMICROSCOPY OF THE EYE


972 and Fig. 358) The reflex from these fibers ends at the suture, which in itself appears as a dark stripe. Vogt*’^" demonstrated this point in 1921 and compared the apparent crestlike appearance of


Fig. 358. Underlying suture and fiber designs as seen in the mirror zone (specular reflexes of

the anterior and posterior capsule).


the sutures to that of the ribs of an opened umbrella. Although the fiber arrangements on both sides of a suture are anatomically symmetrical, the appearance is different in specular reflex because with the illumination directed from one side the reflections from these symmetrical abutting fibers are necessarily dissimilar. Since the specular reflex of the fibers is derived mainly from their surfaces and not the fiber extremities (at the suture), the reflex at border regions of the sutures is light deficient and causes the suture itself to appear as a dark line; according to Vogt’s description as dark crests. The latter also noted what appears to be a slight depression or groove in the shagreen field of the anterior capsule, concentric with and just at the margin of the pupillar)'- edge - where the posterior surface of the iris normally contacts the capsular surface. This condition can only be seen in the young where it forms a slightly depressed concave band parallel to the pupil. The fact that the contact of the iris could produce such an impression speaks for the softness of the capsule and the underlying fibers and also might explain the reason for the location of Vossius’ traumatic ring opacity

^ In my opinion these features are not directly related to the capsular shagreen but result from intrinsic specularity of the fibers below it. As in the case in the cornea, when viewing tlie anterior mirror zone one may at the same time see specular reflexes behind it (Volume I, page 103).


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 985


seen in the young. In addition, the shagreen fields, as would be expected from the fact that the thickness of the capsule varies from place to place between the pole and equator, differ as one observes it in different areas. In some sectors the fiber design may not be sharply visible. As a matter of fact in the polar region the fiber design is frequently seen better when the posterior or prefocal part of the beam is employed, because as previously mentioned their reflection is independent of that of the shagreen of the hyaline capsule. However, it should be remembered that what is seen in the zones of specular reflection depends on the angle between illumination and observation, and the appearance of details will vary as we alter this ever so slightly. In addition, generally speaking just as the zones of discontinuity are better differentiated in axial regions as compared to the far periphery so are all their mirror zones. As a matter of fact the reflexes of the latter are not seen peripherally.

Epithelium. Using a higher magnification, 35 X to 60 X, the outlines of the epithelium cells themselves may be seen as smaller irregular glints within the design of the coarser shagreen and only within limited areas (Fig. 354). The difficulty in seeing the outline of the lens epithelium clearly in the zone of specular reflection as compared to the corneal endothelium is probably due to the fact that the light reflected from the more reflecting capsule in front blurs them somewhat. In addition (Vogt) the difference in index of refraction between the epithelium and the capsule as well as between the epithelium and underlying cortex seems to be less than that between the cornea and the aqueous. The margins of the epithelium cells are best seen in the young, especially with the aid of the cylindrical light bundle. They do not appear as a well-formed mosaic as is the case with corneal endothelium, but for the fact mentioned are seen as irregularly outlined reflecting dots, a few in each shagreen field.

Shagreen Spheres. This term, originated by Vogt, applies to small spheric to ovoid bodies from 20 to 60 in diameter seen in the anterior mirror zone of the lens toward the periphery (Plate LIX, figs. 5, 6). Their exact significance is unknown. In order to be seen maximum dilation of the pupil is necessary since they are usually


PLATE LIX


Fig. I. Suture lines (slightly dilated) seen at the level of the adult nucleus in an old person. Diffuse illumination.

Fig. 2. Suture lines (same case as Figure i) as seen by retro-illumination, by light reflected from the deeper parts of the lens.

Fig. 3. Suture system seen by diffuse illumination in a man of 50 years.

Fig. 4. Same as Figure 3 viewed by direct focal illumination.

Fig. 5. Relief and suture system of the surface of the adult nucleus. Showing shagreen spheres in the specular reflex. Diffuse illumination.

Fig. 6 . Same as Figure 5 as seen by direct focal illumination.


986



THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 989


found in a zone corresponding to the middle and peripheral onethird of the visible anterior lens surface; occasionally they may be found more axially. The wide beam and lowered illumination should be emplo)'^ed in order to veil the brilliancy of the reflection of the capsular moiety of the shagreen. The spheres appear as black holes or spots in the shagreen field. By indirect illumination (at the side of the mirror zone) a glistening mirror reflex from them proves that they are not artifacts and also shows their spheriodal shape. They are rarely seen in the young, but in adults and the aged they are constant and presumably physiologic findings. They are best seen in older persons with cataractous lenses. Unlike vacuoles, shagreen spheres cannot be seen with the ophthalmoscope nor by means of retroillumination using the reflected light from the mirror zone of the posterior capsule. They ma)'’ represent verrucosities of the lens fibers.

Va'mt Iridescence {Color Display) of the Anterior Mirror (Shagreen) Zone. When observing the anterior lens mirror region of adults or of the aged, one is frequently struck by the presence of a rather faint color display not unlike that seen when oil is floated on water (Plate LVIII, figs, i, 3)* The tints vary from pale green to a reddish yellow. This type of iridescence is also found in the posterior capsular shagreen. This should not be confused with the more marked iridescence seen in complicated cataract (pages 1169, 1285) or in cases of chalcosis lentis wherein copper is deposited in the subcapsular layers following the intra-ocular introduction of a cuprous foreign body. In his earlier work Vogt stated: "This physiologic iridescence may be due to delicate remnants of the embryonal capsular membrane,” while later he stated that it may be due to the interference phenomena caused by a very thin layer of fluid less than 0.2 p, basing this newer opinion on his findings in cases of traumatic cataract. Evidently this display of color must optically be due to some interference phenomenon within the capsule itself. Very little is known

In order to dispel any idea that iridescence was brought about by chromatic aberration or diffraction within the illuminating system, Vogt directed the beam on a white disk of porcelain. In this case color aberration occurs only at the margins of the illuminated area whereas in the shagreen or in the case of complicated cataract it occurs within the center of the illuminated areas.


990


BIOMICROSCOPY OF THE EYE


concerning the morpholog)'- and physiology of the lens capsule, and it has only been since the advent of biomicroscopy that our attention has turned to it.

ANTERIOR STRIPE OR LINE OF DISJUNCTION

This thin stripe or zone of discontinuity, which is found just behind the capsule stripe (but is also present in front of the posterior lens capsule), can be clearly identified only with the narrow beam (Fig. 355). When the width of the slit opening is reduced to 0.5 mm., the width of the beam will be 20 p. In the axial regions or poles, the stripes of disjunction seem almost to fuse with the capsule, but with the narrowest beam an area of separation between them can always be demonstrated. They are present in the young individuals and even in infants when it is possible to examine them biomicroscopically. Peripherally the space between these stripes and the capsule gradually widens, producing the so-called peripheral divergence. Except for its peripheral divergence this line might be compared to the double line (seen only in optic section) on the anterior corneal surface. However, in the case of the cornea the second line represents the surface of Bowman’s membrane. (See Vol. I, Fig. 69 .) Peripheral divergence is also a feature of the deeper zones of discontinuity. Vogt has designated this stripe as "abspaltungsstreifen,” the exact translation of which signified a progressive widening of separation toward the periphery. In other words the radii of curvature of these stripes diminishes peripherally. This anterior stripe is in contrast to the other zones of discontinuity less distinct with age, especially as the relucency of the cortex becomes greater. Vogt was unable to find them in cases of cataracts occurring in myotonia, tetany, and in the separation of the zonular lamellae in glass blower’s cataract.

ANTERIOR STRIPE OF THE ADULT NUCLEUS

This grayish white stripe or band represents an illuminated section of the adult nuclear surface (Fig. 355; Plate LVIII, fig. 3). Since

This zone of discontinuity was first described by Gullstrand.'*®* Vogt described the other zones of discontinuity in 1917-1918.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 991


accessory faintly visible stripes may occasionally be seen in the cortex, the term "anterior stripe of the adult nucleus” refers to the deepest and most luminous one that lies between the anterior line of disjunction and the surface of the anterior fetal nucleus. Even as we narrow the beam, this illuminated area is never as sharply defined as the capsular stripe or disjunction lines; consequently except for the purposes of localization it is preferable to observe it with the wide beam or at times in older persons when it becomes more relucent and highly reflective to study even a greater part of its relief by diffuse illumination. It should be repeated that even though some of the zones of discontinuity appear as lines or possibly surface planes in optic section, actual^ they have a very definite sagittal thickness. In children, where all the zones of discontinuity are less reflective, a faint stripe is found deeper to the line of disjunction anteriorly, and in front of it posteriorly (Fig. 356). Although they are called the "adult nuclear stripes” it is still not known whether they actually are the same stripes (so termed in adults) . Probably they develop into them (page 992). Already during adolescence these zones of discontinuity, when viewed with the narrow beam, no longer appear as sharp lines as for instance the capsule stripe or disjunction lines, but rather as a hazy band having a definite sagittal thickness. With age the width of this band increases, especially as it approaches the periphery (equator). So that it is always thicker here than in the axial region of the lens. The fact that this band becomes thicker and more relucent with age (while the other internal zones of discontinuity become less reflective) suggests that it may be formed by the coalescence of several newly formed zones of discontinuity. At the end of the first decade, it is already possible to see a stripe which probably corresponds to the future highly reflecting band of the adult nucleus. Auxiliary stripes in the cortex were already noted by Vogt and Koby. Goldmann went a step farther and

- With this in mind, Vogt studied a lens of a freshly removed gliomatous eye of a 13-month-old infant. He found that the lens was very thick sagittally and that the stripes of disjunction were equidistant (no peripheral divergence) from the capsule. The zone of discontinuity, which corresponds to that of the adult nuclear stripe, was present but was much more curved. Because of its extreme curvature, he suggested that this stripe might correspond to the outer embryonal zone (fetal). In a very cooperative z-year-old child I found this stripe outside the fetal one.


992


BIOMICROSCOPY OF THE EYE


showed that with arc-lamp illumination it is possible to see a series of these Hnes in the cortex which increase in number with age. These lines are formed by the progressive growth of new fibers which are being continually displaced inward. With periods of retardation in growth rhythm a group of fibers may become more reflective or develop a difference in refractive index and thus optically produce a Hne.

This idea occurred to Goldmann after seeing faint lines (zones of discontinuity) appear in animal lenses at the place where damaged layers of fibers were receding to deeper levels and that these lines optically were the expression of transient inhibition of growth. In order to explain the genesis of the peculiar appearance of the adult nuclear bands in man he observed 114 persons of various ages. In these examinations he used the biomicroscope with an arc lamp source and a special measuring ocular. In 66 persons with normal lenses he made the following observations: (i) The distance between the disjunction line and the capsule does not show any definite relationship to age. (2) The distance between the anterior margin of the anterior senile nuclear stripe and the anterior capsule decreases slightly with (3) The distance between the posterior margin of the anterior senile nuclear stripe and the anterior capsule increases markedly. (4) The most striking change is the increase in thickness of the so-called "band” of the anterior adult nucleus.

This would indicate that the apparent increase of the reflective power of the adult nuclear band with age is due to its great increase in thickness. Examination with the arc source of illumination and narrow slit opening revealed that the adult nuclear band was composed of a series of fine lines. Similar lines were also found in the cortex and extended up to the disjunction line. In all cases these auxihary lines were seen more readily at the periphery than axially. The number of the lines or zones of dicontinuity increased with age. In a person 20 years of age, he found only three or four stripes while in an individual of 80 years he found as many as twenty. However, these auxiliary or elementary lines were not visible in every case even with the arc source; in most instances, it is not possible to


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 993

see them with the ordinary nitra bulb light source. Goldmann estimated that approximately one elementary line is produced every two or three years. According to this, elementary lines are laid down


Fig. 359. Diagram showing accessory stripes in the formation of the band of the adult nucleus.

(After Goldmann.)

subcapsularly and with age the older ones are pushed deeper."' Owing to the increase in number and to coalescence, the sagittally thickened and increasingly reflective band of the adult nucleus results. In other words, the increase in reflection of the adult nuclear surface results from the increase in number of elementary lines, thus producing a reflecting layer of greater thickness, rather than an increase in reflecting power from single layers. Apparently these lines are not the expression of a special kind of fiber which has a rhythmic growth but rather a phase through which every fiber has to pass. There is also the possibility that the mechanism of internal lenticular accommodation plays a role in the formation of these lines. With age, the anterior border of the thickened adult nuclear stripe progressively approaches the capsular stripe. Hence the distance that the newly formed lines have to travel is progressively less. This process in which the nucleus increases in thickness at the expense of the younger new fibers of the cortex, may progressively limit the latter in performing the act of accommodation.

According to Goldmann’s investigations it is possible to differentiate three zones of elementary stripes which correspond to the

Goldmann suggests that the following experiment will give one an impression of this mechanism: "If one puts many cellophane plates, one on top of the other, fills the interspaces with alcohol and squeezes them between two microscope slides, and then observes them with the narrow beam of the slit lamp, one will have a picture of a large zone of reflexes like the senile nucleus band in which single elementary lines are visible, but nearly always fewer than the number of plates. The same plates observed in difltuse illumination show the dull luster which is very similar to the inner reflection of old lenses.”


994


BIOMICROSCOPY OF THE EYE


different periods of life (Fig. 359). The first group which he designates as Ai are seen early in life (before the twentieth year) and are located just behind the disjunction lines. A dark interval separates


Fig. 360 Fig. 361

Fig. 360. Ridges of the adult nuclear relief. (After Vogt, from plastic model.) Fig. 361. Knobs of the adult nuclear relief. (After Vogt.)


them from the outer embryonal (fetal) nuclear zone. Between the twentieth and fortieth years another series of lines appears in front (capsule- ward) of Aj. He calls this group A2. By this time the deeper group Ai becomes fainter, grayish and dull, so that its component lines are no longer easily seen. It may be that these join with the outer embryonal nucleus. Toward the end of the third decade the number of lines in Ao increases (the zone getting thicker) and become increasingly brighter and yellowish. It is the condensation of this group (Ao) which forms the highly reflecting band of the adult nucleus seen in older persons and which presents the typical relief of the adult nuclear surface (page 995) . After 40 years of age, another group of lines (A3) forms subcapsularly in the cortex. In the direction of A2 the)'^ are not sharply demarcated, but anteriorly they are well individualized and are whitish.

With age, the anterior band of the adult nucleus becomes so relucent that it reflects more light than the capsule stripe. Also this zone develops a peculiar maplike relief, erroneously interpreted


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE


995


by von Hess as the beginning of a senile cataract. This effect can easily be seen if one directs the unfocused beam (diffuse illumination) with a large angle of incidence into the wide pupil. In the axial region, the many branched suture system (from 6 to lo rpain branches and from lo to 15 sub-branches) stands out as if elevated from the surface with a characteristic design of the lens fibers (Eig, 360; Plate LIX, figs. 3, 4) . In the periphery peculiarly shaped knoblike prominences are seen (Fig. 361). These round or oval elevations are never confluent. At times they reflect a little light and appear glossy. However, it should be pointed out that the relief of the adult nucleus varies in appearance from case to case. In some it is very marked while in others it is faint and blurred. The vertical ridge seen only in the axial parts is probably the primary one and hence tends to be broader and higher than its branches. Employing a wide angle of incidence of illumination and changing the direction of the light in the pupil from the temporal to the nasal side and vice versa, shadows formed on the less illuminated sides of the ridges will accent their relief and cause them to stand out sharply above the surface (Fig. 360) . The ridges may be absent; in this case the sutures will appear as dark lines on a smooth surface. Frequently, when the ridges of the sutures are not seen, the surface will be marked by the presence of the knobs (Fig. 361 ) . The design of the relief corresponds to the direction of the sutures and consequently extends itself in a continuous way to the periphery where the ridges gradually flatten out. With higher powers, reflections from the fiber design are commonly seen in the form of fine lines. These lines (bundles of fibers) run at right angles to the ridges and as they cross them become convex in a frontal direction. In other cases the center of the ridges may be depressed, forming a sort of trench. It may well be as Vogt suggested that these various appearances of the nuclear relief hint towards shrinkage of the adult nucleus. In order to show the incidence of the relief Vogt and Lussi studied a series of 628 subjects. Of this group, 75 had coronary opacities, 75 had other forms of opacities, 20 had nuclear cataract and in 83 the opacities were negligible. Table XVI was taken from Liissi.


996


BIOMICROSCOPY OF THE EYE


From these figures it will be seen that the relief can rarely be distinguished before the twenty-fifth year. It should be pointed out that in very rare cases a faint relief of the outer fetal nucleus may be present; but as this does not have the characteristics of the adult nuclear relief and is found in younger individuals, there is little likelihood of confusion. The relief of the surfaces of the inner fetal nucleus is plainly marked by the erect and inverted Y-sutures.

Table XVI

FREQUENCY OF THE RELIEF


Age of Subject

Number of Subjects

Pronounced

Relief

Slight

Relief

I to 10 years

10 to 20 years

7

84

1

I i

1


20 to 30 years

1 16

4

9

30 to 40 years

83 1

3

12

40 to 50 years

87

26

19

50 to 60 3'^ears

87

32

27

60 to 70 years

92

24

20

70 to 80 3ears

67

10

5

80 to 90 3'^ears

5

1

I


Total

628

lOI

92


From Liissi.


It should be remembered that these appearances are not opacities and, even when prominent, do not disturb vision. The}^ cannot be seen by transillumination with the ophthalmoscope. Pathologic features such as vacuoles just below the nuclear surface tend to be larger in size and are more circumscribed than similar subcapsular changes (Fig. 352 B, C). They can alwa^'^s be seen as vacuoles by retroillumination (using the shagreen reflex area of the posterior capsule as a light source) and when marked may influence vision. It has been suggested that the hemispherical projections are produced by a collection of fluid.


il/tu/j


Fig. 362. Increase in thickness of the adult nucleus as the periphery is approached.


Fig. 363. Peripheral divergence of the outer zones of discontinuity. A. 21-year-old person. The more or less sharp surface of the adult nucleus in a young person widens out in a zone of increased diffuse reflection as the equator is approached. This is seen best when the narrow beam of high light intensity is projected through the lens very obliquely. As a result the nucleus equator becomes drawn out similar to the neck of a bottle. The widening of this zone (peripheral divergence) is caused by the traction of the zonule. This appearance is not found in cases where zonular traction is absent, e.g., sphereophakia. b. 77-year-old person. The surfaces of the adult nucleus do not widen and become diffuse as they approach the equator. Hence the condition seen in A is absent. Diagrammatic. (After Vogt.)


997


998


BIOMICROSCOPY OF THE EYE


The surface of the adult nuclear stripe (especially in the young) blends into a zone of increased diffuse reflection as it approaches the equator. Here it thickens sagittally so that often it cannot be recognized as a surface (Fig. 362). In the aged this zone of increased diffuse reflection does not occur (Fig. 363 B). In the axial region the sagittal thickness of the adult nuclear stripe becomes thinner. This is of optical significance in the pupillary portions of the lens and of lesser optical importance in the periphery where, due to widening, there is a more gradual transition of refractive index. According to Vogt this increase in thickness peripherally has to do with the pull of the zonule since it is not seen in spherophakia, a condition characterized by the absence of zonular tension. Another probable instance of the effect of the zonular pull is morphologic all}'^ evidenced in the normal lens by the augmented tapering of the adult nucleus in the equatorial zone. Particularly in the young both anterior and posterior surfaces approach each other to taper out and almost join, being separated or split as it were by an extension of the central interval (Fig. 363). The peripheral divergence of the adult nuclear stripes should be noted. This, together with the shorter radii of curvature of the nucleus, causes a greater sagittal thickness of the cortex in the peripher}'^ as compared to the axial region. This thickening in the periphery (manifested by the peripheral divergence of the zones of discontinuity) results in a flattening of the lens surface. In this way the shape of the lens is more disklike and only with relaxation of the zonule can its sagittal diameter increase (process of accommodation) .

Mirror 'Zones. (Specular Reflecfional) of the Adult Nuclear Surfaces. Both surfaces, anterior and posterior, of the adult nucleus exhibit mirror reflexes or zones of specular reflection. Because of the smaller radius and consequent greater surface curvature, the mirror zones of the adult nucleus are smaller than those of the capsule (anterior) . Not only are the)'^ smaller in size but are alko less bright in intensity. The anterior mirror zone of the adult nuclear surface is yellowish white in color, and its posterior one, especially in the aged, is ^’■ellow-orange or even reddish (Plate LVIII, figs. 2, 4) . Owing to the difference in curvature between the capsule and surfaces of the adult nucleus it is impossible to see the reflexes, simultaneously


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 999

with the same angle of observation. One first focuses the anterior shagreen and by changing only the angle of observation (the angle of illumination is not changed) ever so slightly in the direction of the shagreen the mirror zone of the adult nucleus will be seen. As this comes into view the shagreen is no longer seen. However, owing to the fact that the specularly reflected rays from any one given point can only be perceived in one ocular, alternate opening and closing of each eye will frequently bring them into view successively without changing the actual angle of the microscope. The same will hold true in a reverse way when viewing the posterior shagreen and the mirror zones of the posterior adult nucleus surface. As Vogt has pointed out, the reddish color of the posterior adult nuclear layer is not entirel) caused by the yellow color of the posterior portions of the lens (physiolgic with aging) because then the color of the posterior shagreen should also be of the same reddish hue which is not the case; instead this is a bright yellow. The light of the posterior capsular shagreen passes through the lens twice. Evidently the zones of discontinuity have special differences of intensity of reflection and are "selective.” In the normal eye, no special design or features can be made out in the zones of specular reflection of the surfaces of the adult nuclei.

ANTERIOR OUTER STRIPE OF THE FETAL NUCLEUS

(outer embryonal stripe of vogt)

Surrounding the opposed coffee bean-shaped inner fetal nuclei the surfaces of which are so characteristically marked by the Y-sutures, are the outer stripes of the fetal nucleus (Figs. 351, 364 ; Plate LVIII, fig. 6) . In adults and in the aged, these stripes become increasingly difficult to recognize as definite zones of discontinuity. As previously mentioned, their relationship to the so-called adult nuclear stripes as seen in the young and to the inner fetal nucleus is not precisely known. Since the time of formation or development of the anterior and posterior outer stripes of the fetal nucleus has not been established it is not entirely correct to call them "infantile” stripes, as has been done by some writers. All we can say at present is that they form either just before or just after birth. From all the available


1000


BIOMICROSCOPY OF THE EYE


material at hand and from my own observations, I believe that they are present at birth and consequently I prefer the term "outer fetal stripes.” Actually, birth creates no sudden change in the develop


Fig. 364. Diagrammatic representation of the zones of discontinuity as seen in optic section (1-12). i, Anterior capsule stripe; 2, anterior disjunction stripe; 3, anterior adult nucleus stripe; 4, anterior adolescent stripe; 3, anterior outer stripe of the fetal nucleus; 6, anterior inner stripe of the fetal nucleus; 7, posterior inner stripe of the fetal nucleus; 8, posterior outer stripe of the fetal nucleus; 9, posterior adolescent stripe; 10, posterior adult nucleus stripe; ij, posterior disjunction stripe; 12, posterior capsule stripe.


ment of the lens. The attempt to classify the zones of discontinuity located outside the inner fetal nuclei, as infantile, adolescent, adult or senile is not justifiable because it gives the impression that these zones form suddenly during the different epochs of life. Actually all that happens is that with age and growth of new fibers some are accentuated, e.g., adult nuclear stripes, and the others either fuse or because of increased relucency of the intervening layer become less obvious as zones or places where a sudden change in the index of


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1001

refraction occurs. In the newborn, the fetal nuclei are separated from the capsule only by a comparatively thin area, occupying relatively a much greater portion of the whole lens than it does in adults. In spite of the fact that with the growth of new fibers between the fetal nuclei and the capsule and the resulting increase in thickness of these layers (adult nucleus and cortex) , the total sagittal thickness of the whole adult lens is hardly greater than that of the newborn. This would indicate, according to Vogt, "that the embryonal nucleus (fetal) suffers an important decrease in size by shrinkage during life.” Koby states that these stripes (anterior and posterior outer fetal nuclear) "although narrow, are nevertheless sharp, and central to the sutures there is an increase in optical density, not sufficient!) sharp and localized to be considered as a band of discontinuity, so that it is rather a question of a very diffuse zone. With age the peripheral (outer) and central (inner) bands gradually fuse.” Whether this assumption is correct will only be proven when the growth of the lens in the young is more systematically studied with the biomicroscope. The other possibilities are that these structures either merge or become the "adolescent” stripes or that as the relucency of the entire adult nucleus increases the change in index or refraction at these points no longer is sufficient to produce a zone of discontinuity. Rarely in the young faint zones of discontinuity between the outer stripes of the fetal nucleus and the adult nuclear stripes may be found. These so-called adolescent stripes are usually not seen in adults and even in the young are inconstant (Figs. 351, 364). When present both these stripes show in the equatorial regions the phenomenon of peripheral divergence. The outer stripes of the fetal nucleus are more often present than this rare supernumerary line.

ANTERIOR INNER STRIPE OF THE FETAL NUCLEUS

(inner embryonal stripe of vogt)

In the central part of the lens are the two coffee bean- or biscuitshaped nuclei, indicated biomicroscopically by the anterior and posterior inner fetal stripes. Between them is the so-called "dark

As mentioned on page 976 the fetal nucleus, the core of which is the dark interval or embryonic nucleus, consists of that part of the lens that is bounded by fetal Y sutures. Koby states: "These points of references are much more precise for the fetal nucleus than the


1002


BIOMICROSCOPY OF THE EYE


interval,” an area whose relucency almost corresponds to that of the normal aqueous. The coffee-bean like appearance of these stripes never varies and represents optically a sagittal section through the


Fig. 365. Anterior fetal Y suture.

thickness of the inner fetal nucleus. The location of the nuclei is marked by the presence of the well-known Y-sutures. The anterior inner stripe of the fetal nucleus, with its erect Y-sutures, is much less relucent than the posterior one and consequently is somewhat more difficult to see. After obtaining the posterior stripe, easily localized by the inverted Y-suture, one focuses in the slightly relucent area in front of it (zone of anterior inner fetal nucleus), and with slow gentle oscillations of the beam, suddenly the fainter anterior upright Y will be discerned. It stands out, in youth, whitish against the less relucent dark background. (Figs. 345, 346.) This whitishness is the result of reflections from the feathery fibrillary appearance of the extremities of the lens fibers. As the internal relucency of the lens increases with age these sutures appear dark

bands (stripes of discontinuity).” The fetal nucleus consists of that part of the lens which embrj’ologically develops after the completion stage of the primary vesicle. Its fibers develop from the capsular epithelium at the equator and grow around those which in the primary lens vesicle extended forward from the original epithelium of the posterior capsule, to fill its cavity. The secondary or fetal fibers in their development grow in and separate the capsule from these original sagittally directed ones of the primarj' lens vesicle. As time goes on the outlines of the primary lens fibers become indistinct and eventually even at birth this area appears as a dark nonrelucent zone separating the two coffee-beanlike fetal nuclei!. The dark interv-al never shows any trace of a suture system nor do the branches of the fetal sutures ever enter it.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1003

against the brighter background. However, in nuclear cataract the fetal sutures are delineated as white lines contrasted to the surrounding uniform milky gray of the central lens areas. Generally the angle between the two main branches of the anterior Y is wider than that of the posterior, giving the anterior Y a somewhat extended appearance (Fig. 365). Also the tendency to subbranching of any of its three arms is less than that of the posterior A. As a rule, save for an occasional dichotomous branching of the lower limb, the arms of the anterior fetal suture do not ordinarily branch. Often the fetal sutures are inclined from the vertical and appear as if they were reclining. Also at times the relations of the two Y’s are such that they stand obliquely to each other in such a way that their vertically directed arms (anterior inferior and posterior superior) are parallel to each other. The vertical arm of the anterior Y and the horizontal arm of the posterior X the first to form and also are the first to show subdivisions. This corresponds to what is seen in lower forms of life, e.g., certain fish where the anterior suture of the lens is a vertical line (no branchings) and the posterior one is represented by a horizontal line only.*’' It is interesting to note that in this region axially (anterior inner fetal zone) Vogt found in 25 per cent of otherwise normal lenses small groups of whitish dots which cannot be seen ophthalmoscopically and which do not affect vision. (He has termed these "the anterior axial embryonal cataract” [page 1055]).

the posterior inner fetal (embryonal-vogt) stripe

The dark interval separates the fetal nucleus into two halves. It will be seen that the dark interval divides the entire lens in the equatorial plane into two parts which are almost identical except for variations in curvature and in certain details of markings. Similar to the two separated halves of a coffee bean, the configura In his photomicrographs of rabbits’ lenses impregnated with silver nitrate Vogt shows a similar arrangement. The anterior suture appears like a vertical line and the posterior as a horizontal one. In each case the fibers run at right angles to the direction of the suture line and widen as they approach the suture itself. In the development of the suture in higher animals and also in man the phylogenetically older vertical or horizontal part of the suture starts to deflect or bend. This bending is always a forerunner of branching. In other words, the suture changes its direction slightly before it branches.


1004


BIOMICROSCOPY OF THE EYE


tion of the surfaces of the inner fetal nucleus is convex externally and to a lesser degree somewhat concave internally."'

The posterior L suture, which permits biomicroscopic localization


Fig. 366. Posterior fetal suture.


of the posterior inner fetal nucleus, is more easily seen than the anterior Y. As a matter of fact, in youth the posterior inner fetal stripe or zone is usually the most relucent of all, and it is wider axially than peripherally as compared to the other zones of discontinuity where the opposite holds true.

The fibrillations which represent reflections from the fiber ends as they meet to form the suture are best seen at the borders of the posterior X (Fig. 366) . The two lower legs of the A join the upper vertical at an obtuse angle in the form of a gothic arch, the lower legs often extending out almost horizontally. The upper (phylogenetically 3'^ounger) vertical arm only very rarely shows any branch

" The greater curv'ature of the outer fetal nuclei causes this zone to converge toward the inner fetal nuclei in the periphery. This differs from the peripheral divergence seen in all of the peripheral areas (equatorially) of the outer zones of discontinuity. It should be remembered that the greatest sagittal growth of the lens occurs during embryonic and fetal life. The lens is somewhat spheroid. Although the lens fibers continue to develop after birth, the shape of the lens flattens. This means that the peripheral parts (between the zones of discontinuity) thicken relatively more than the axial regions, resulting in peripheral divergence of the zones of discontinuity. According to Vogt, the peripheral divergence results from a thinning (sagittally) of the individual lens fibers as their ends abut upon the suture, e.specially as the sutures (cortical and adult nucleus) grow in length. So that the sagittal thickness of each fiber, except for the fetal nuclei, is less in the axial regions than in the peripher)-. This state of affairs is abetted by the tension of the zonule.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1005

ing, in contrast to the lower arms the ends of which practically always branch in a dichotomous way. As in the case of other sutures a slight deflection in the course of the main arm precedes the subbranching. Histologically, Rabl has shown in pigs that the posterior A-suture develops earlier than the anterior. According to Vogt this is probably also true in humans, as indicated at birth when the posterior Y is already further developed than the anterior. His measurements of the length of the fetal suture legs (made in fetuses of from (3 to 8 months) were approximately 1.25 mm. to 1.5 mm. for those of the posterior A up to the sites of subbranching and from 1.5 to 1.75 mm. for the lower leg of the anterior Y.

The posterior A, situated directly in the axis of the lens, aids in locating the posterior pole of the lens when looking for remains of the arteria hyaloidea propria, since the polar area of the posterior capsule lies behind and nasal to it.

THE POSTERIOR OUTER FETAL (EMBRYONAL-VOGT) STRIPE

This stripe, which corresponds to the anterior outer fetal stripe, likewise may not always be sharply delineated (Fig. 3(34). Because of the greater curvature of all the posterior zones of discontinuity as compared to the anterior, the radius of curvature of the posterior outer fetal stripe is less than that of the corresponding anterior one. With age, sclerosis of the central and adult nuclei also tends to diminish its visibility. Added to this is the commonly seen increase in yellowness of the posterior parts (posterior cortex and posterior adult nucleus) .

THE POSTERIOR ADULT NUCLEAR STRIPE

The stripe of the posterior adult nucleus is the posterior counterpart of the anterior adult nuclear stripe. This zone, which also is the thinnest in the axial region, broadens out somewhat as it approaches the periphery and shows the same characteristic peripheral divergence. (See Figs. 362, 363.) In other words, the distance be Corresponding to those in the anterior cortex, fainter accessory bands may usually be seen in the posterior cortex. However', these will hardly be confused with the more distinct and reflecting stripe of the posterior adult nucleus.


1006 BIOMICROSCOPY OF THE EYE

tween the stripe of the posterior adult nucleus and the posterior line of disjunction is greater peripherally than axially. The posterior surface of the adult nucleus likewise becomes more marked with age and shows the same type of relief as the anterior but in reverse, so that a similar structure that appears as a prominence on the surface of the anterior adult nucleus will appear as a depression on the surface of the posterior and correspondingly a depression anteriorly will appear as a prominence posteriorly. The same fiber design and the same variations occur as in the appearance of the relief of the anterior adult nucleus surface. The zone of the posterior adult nucleus should first be localized (just behind the posterior X ) by optic section axially, where the markings are most pronounced. Then, in order to get more surface area of reflection the pre- or postfocal part of the wide beam should be employed. To obtain a larger (specular) reflecting zone a change in angulation between illumination and observation may be indicated. As previously described, the mirror zone of the posterior adult nucleus surface, although somewhat smaller than the anterior, is more orange in color, especially in older individuals (Plate LVIII, figs. 2, 4) . This is even true when it is compared to the shagreen area of the posterior lens capsule (page 974) . Sharp focusing may in some cases disclose a delicate fiber design, but ordinarily it appears, depending on the width of the slit opening, as a small rectangular area of illumination covering only a small part (in height) of the posterior adult nucleus stripe. As the beam is diffused (pre- or postfocal illumination) the lateral edges become less sharp and gradually fade into the surrounding nonspecular areas.

THE POSTERIOR STRIPE OF DISJUNCTION

Sharp focusing of the posterior capsule stripe with the narrow beam will disclose a double stripe which, except for its greater curvature, seems- to differ in no way from that of the anterior double stripes. The one just in front of the posterior capsule stripe is the posterior stripe of disjunction (Figs. 351, 364). That this zone of discontinuity does not represent the inner limit of the epithelial


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1007


layer is proved by the absence of epithelium histologically in this posterior zone. It probably represents a well-defined stratum in the subcapsular cortex in which, owing to a physico-chemical alteration of the fibers, a change in index of refraction occurs which is visible only in optic section. This stripe also reveals the typical peripheral divergence equatorially; it appears homogeneous and has no apparent surface markings.

THE POSTERIOR CAPSULE STRIPE

This stripe delimits the posterior surface of the lens and, depending on the width of the focused beam, represents an illuminated section of the posterior capsule (Plate LVIII, fig. 2). Ordinarily it appears as a curved bluish-gray stripe (concave anteriorly), its curvature corresponding to that of the posterior capsule. This surface can be focused in two ways, either by focusing directly along the path of the beam to the place where the lens relucency ceases and the fibrillar structure of the trembling vitreous framework comes into view or by focusing on the zone of specular reflection of the posterior capsule. As previously mentioned because of the thickness of the lens it is impossible to observe its entire sagittal thickness at one time in the focal part of the beam even with the lo-mm. illuminating lens or the Poser diaphragms. (See Vol. I, pages 48, 77.) When the focal part of the beam passes through the anterior parts of the lens, the posterior parts are illuminated by postfocal or somewhat divergent rays and the zones of discontinuity are no longer sharp (Plate LVIII, figs. 1,2). Conversely, when the posterior parts of the lens are traversed by the focal part of the beam, the anterior illuminated section is seen in the prefocal part of the beam. After the posterior capsule stripe is sharply focused, lateral movement of the beam (until the angle ^f observation equals that of illumination) will reveal the zone of specular reflection (posterior shagreen) (Plate LVIII, fig. 2 ). If one wishes to obtain specular reflection from a point more nasally, then the patient is instructed to direct his gaze in that direction, or temporally for the mirror region of the temporal parts of the capsule. Alternately, if the catoptric image


1008


BIOMICROSCOPY OF THE EYE


of the illumination lens"' of the posterior capsule is focused and it appears in the anterior parts of the lens and holding this image in view, deeper focusing of the microscope will suddenly reveal the shagreen of the posterior lens capsule when its point of focus corresponds to the posterior capsular plane. In this manner a shagreen picture is obtained which, although smaller, is even brighter than that of the anterior mirror region. The design of the posterior shagreen f is much finer than that of the anterior capsule, but it shows in addition reflections from the posterior subcapsular fibers as they radiate toward the sutures. The posterior cortical sutures appear as dark lines crossing the mirror reflex and are best seen just outside the axial region. As already described (page 972) in the discussion of the origin of the shagreen of the anterior lens capsule, the simultaneous appearance of the fiber design and suture lines in the shagreen does not necessarily indicate that they contribute to its formation but rather that the coincidence results from a superposition of the separate optical phenomena, viz., separate specular reflection on the one hand from the lens fibers and on the other hand from the posterior capsule. (See also Morgagnian cataract, etc.) Optically, just as in all other reflecting surfaces, defects (depressions or elevations) are nonreflecting in the plane of specular reflection and appear as dark spots in a luminous background. (See Vol. I, page 93.) Normally in the axial region the mirror zone may show dark lines or dots resulting from interference caused by residua of the fetal tunica vasculosa. In focal light these remains (page 1020) stand out as whitish reflecting structures. The presence of these remains is practically universal; they will be taken up in detail under

In the Vogt method of illumination, the spiral of the wires of the lamp (source of illumination) will be seen and in the Koeppe-Poser model the ground glass surfaces of the condensing lens system screens out the image of the wires and all that is seen is a rectangular figure of illumination corresponding to, but naturally much smaller than, the size and shape of the illuminating lens itself.

t The absence of any epithelial layer in front of the posterior capsule precludes the possibility that the design in the mirror reflex is caused by these cells. Koby states: "When a large vacuole exists at the posterior surface of the lens, we have sometimes been able to show that the convex part of the vacuole turned toward the observer, exhibits some shagreen. This observation demonstrates clearly that the lens capsule does not play any important part in the production of the appearance of shagreen.” However, this conclusion is not shared by other workers, as it is now generally believed that the shagreen is an optical manifestation of the posterior capsule.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1009

the heading of congenital anomalies. In the same way any pathologic feature also interrupts the specularly reflected rays from a given area. Whereas in the mirror zone these defects appear dark, in direct focal illumination their color is evident as, e.g., white cellular conglomerations, reddish or yellowish blood pigment and brown uveal pigment. Normally the shagreen varies little in appearance from case to case although its design tends to get more marked with age (shrinkage phenomenon). With complete opacification of the subcapsular cortex, the shagreen gradually becomes indistinct.

THE CORTEX AND THE ADULT NUCLEUS

For our purposes, the cortex includes that part of the lens situated anteriorly and posteriorly between the capsule and the anterior and posterior stripes of the adult nucleus; while the adult nucleus is bounded outwardly by the anterior and posterior stripes of the adult nucleus and inwardly by the anterior and posterior outer stripes of the fetal nucleus."' The cortex, formed by the youngest fibers, is softer and more elastic than the substance contained within the deeper adult nucleus. As already mentioned, although the cortex continues to grow by the apposition of new fibers and as a result gets thicker with age, actually the total sagittal thickness of the lens changes but little. This retention of total lens flatness results not only from the sclerosing and shrinking process within the nucleus but also from the fact that as the cortical sutures of the lens divide

At the time of an extracapsular cataract extraction the hard nucleus may appear quite large, even larger than one would expect from the depth of the cortex seen in older people with the biomicroscope. In these cases very little if any cortex remains behind. In all probability the sclerosing process extends into the deep cortex or outside the layer which, from the standpoint of biomicroscopy, we consider to be the limiting surface of the nucleus. This would indicate that the process of sclerosis is in no way related to the increase in index of refraction which optically governs the zones of discontinuity. Except for this instance, the cortex, particularly its middle and anterior portions (subcapsular) , reacts in an entirely different way from the nucleus to the effects of noxious influences. The harder nucleus merely becomes diffusely cloudy and more relucent, its fibers do not undego degeneration and solution, with resulting lamellary separation, formation of water-clefts, spokes, vacuoles, - eventually forming opaque masses as Is the case in the cortex. The difference in constitution between the central parts of the lens and the cortex is even exemplified by the behavior of hereditary postnatal opacities. Some of these are found predominantly in the axial regions of the central nuclei. Some others, also genetically determined, are chiefly formed in the periphery at the level of the surface of the adult nucleus or deep in the cortex (e.g., coronary opacities). The former are uniformly stationary whereas the latter have progressive tendencies.


1010


BIOMICROSCOPY OF THE EYE


and elongate, the ends of the fibers abutting them of necessity become flatter anteriodorsally in the axial regions.

As the beam passes through the cortical thickness it appears slightly relucent and gray-blue in color. Occasionally in adults, one or more faint concentric accessory stripes of discontinuity may be seen within it. The complicated suture systems within the cortex are usually not to be seen in the young, except in the mirror regions. In the aged, and especially as the cortex becomes more relucent due to appearance of the so-called presenile cataractous changes (water slits and lamellary separation) , the elaborate branching of the suture systems becomes more apparent (Figs. 3(^0, 397). However, even in the young we may find some indications of the suture system of the adult nucleus surface if some relief is present. In adults and in the aged this relief becomes increasingly visible (page 994). Although the cortical sutures and especially those of the adult nucleus appear to lie in one plane, in reality they have a sagittal thickness, extending through the substance from before backward. Because of internal reflection, the biomicroscope does not permit its observation in a uniform or continuous manner. It can only be seen in macerated lens preparations. In such preparations maceration causes the lens to open in sectors owing to rupture of the sutures, and it has been found that the sagittal (depth) extension of the sutures gets greater as the axial regions are approached. However, this splitting does not go through the entire nucleus (Fig. 367). The nucleus splits into two halves in the region of the dark interval. Clinically this separation is seen in cases in which at operation a double nucleus is found. Topographically, in macerated preparations after rupture of the sutures, Vogt likened the intervening sectors to the sections of an orange; however, the sectors are actually made up of concentric layers more nearly resembling those of an onion. Biomicroscopically, the sutures and the zones of discontinuity graphically suggest this type of lens structure. As each new concentric layer develops below the capsule, the older one internal to it is pressed inward. This is clinically illustrated by the subcapsular opacities appearing after an acute attack of glaucoma or following trauma


THE NORMAL LENS; BTOMICROSCOPIC APPEARANCE 1011


which, with time, are found to recede deeper and deeper from the capsule. In addition to the well-known radially directed fibers, there are also concentric fibers forming concentric layers apparently inde


Fig. 367 Fig. 36S

Fig. 367. Preparation showing splitting of sutures and concentric layer formation. (After Vogt.) Fig. 368, Punctate opacities in tiie anterior cortex.


pendent of the others. The radiating fibers were first seen by Rabl in his histologic preparations. He could not demonstrate the concentric lamellae. The anatomic fact of the difference in the direction of these fibers is interesting to us because it explains the basis for the variations in direction of the white lines seen in lamellary separation of the cortex and also concentric arrangement of opacities seen in certain types of cataract, e.g., coronary (page 1095).

Biomicroscopically, it is apparent that the suture systems become extended and more branched the closer they are to the capsule. Again, the arrangement anatomically governs the maintenance of the flat lens in spite of the continual growth of new fibers in the cortex, thus insuring the lens its ability to act in conjunction with r e pull and relaxation of the zonule in the process of accommoda


1012


BIOMICROSCOPY OF THE EYE


tion (see below) . In addition to this the sutures probably play an important role not only in lens metabolism but also pathologically as a "locus minoris resistentiae/’ The ease with which the}^ are separated by fluid forms the basis of the water-clefts or slits. In siderosis and chalcosis lentis the metallic deposits are first found in the sutural areas.

Frequently in adults small isolated white dots are seen in the peripheral cortex. Since, ordinarily, they do not tend to increase either in number or size and apparently have no connection with the onset of presenile or senile cataractous change, they are considered physiologic (Fig. 368).

The Increasing Yelloivish Coloration. Another interesting change, especially in the posterior parts of the lens (cortex and nucleus) is the increasing appearance of yellowness of these parts with age (Plate LXX, fig. 5 ) . Although this is a senile phenomenon, like other senile changes, it may not parallel age in every case, e.g., graying of the hair. Thus, there is great variation among individuals as regards the time of its development (possibly of genetic determination) . As a matter of fact this is also seen in the same individual, where the increase of yellowness in the deeper layers may appear in one eye only or in one eye some time before it develops in the fellow eye. Unquestionably in addition to senescent changes, pathologic states of the lens, especially those in the posterior cortex induced by intra-ocular disease, e.g., glaucoma, predispose to this color change. This change is thought by some observers to be due to an increase in the amount of tyrosine, an amino acid (the precursor of melanin). Others explain its presence optically as a manifestation of fluorescence. When light passes through the human lens even in the very young,*!" ultraviolet, violet and blue rays (of short wave length) are absorbed to a certain degree. One of the effects of this absorption is the production of fluorescence. With age this absorption increases and as a consequence the deeper portions of the lens have a yellow

This has been noted particularly after antiglaucoma decompression and filtering operations. t According to Vogt, even the lens of an infant has a slightly yellowish tinge when compared to the colorless lens of a calf.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1013

to reddish coloration. In nuclear cataract when this process is extreme, cataracta brunescens (brown) or nigra (reddish-black) results (Plate LXX, figs, i, 2, 3, 4). Optically the effect of this increase in yellowness in the posterior cortex and nucleus can be simulated in a normal person by wearing a yellow lens. To some degree this prevents the passage of the shorter rays through the lens and results in a relative form of "blue” blindness. This interference with recognition of delicate shades of blue has been noted in the work of aged painters. For example, in his later years Tintoretto’s blues became more brilliant. The absence of this yellow filter in aphakia accounts for the complaint of "blue vision” in patients after operation for removal of the lens."' As this color-absorption phenomenon progresses, it not only affects blue but tends to pass over to green and even to ^^ellow (yellow-blindness of Vogt). In the latter case, the yellower the light (rays of long wave length) , the more difficult will it be to differentiate between shades of yellow. Vogt refers to the classical example of such yellow-blindness in the masking of the yellow color of the macula lutea when viewed in the ordinary light of the ophthalmoscope.

"With continuing senescence, the yellowish color is most intense in the posterior cortex and gradually fades out in the region of the posterior adult nucleus. In extreme age this change in color advances diffusely, gradually becoming less intense and diluted in appearance anteriorly. One is reminded of the effect obtained in further dilution of an iodine solution, which is reddish to dark-brown in concentration and pale-yellowish with dilution. Optically, as the focal beam passes through the lens, the posterior cortex is seen through all layers in front of it. In other words the light is seen through all layers in front of it. Correspondingly, the light, as seen by the observer, is filtered twice - once as it enters and again as it emerges. This may be a factor in the unusual color of the mirror regions of the posterior adult nucleus (page 974) . Bucklers^’^'* has shown

According to Wald, aphakic eyes are 1000 per cent more sensitive to ultraviolet light than phakic eyes. His experimental work disclosed the interesting fact that persons with aphakia can read a chart illuminated by "black light” otherwise invisible to phakic individuals.


1014 BIOMICROSCOPY OF THE EYE

some beautiful illustrations demonstrating spectroscopically the absorption of colors as light is passed through yellow filters.

RELATIVE PROGRESSWE CHANGES IN THICKNESS BETWEEN THE CORTEX AND ADULT NUCLEUS

In order to confirm the fact that the cortex increases in thickness progressively with age and that paralleling this there is a relative decrease in thickness of the nucleus in relation to the total lens thickness, Vogt made elaborate and extensive lens biomicroscopic measurements on 19 persons varying in age from 12 years to 77 years. He made his measurements with an ocular micrometer, considering the total thickness of the lens as i (Fig. 369A, B). His results were percentage figures. Analyzing them (anterior and posterior cortices combined) as compared to that of the adult nucleus, Koby (after Gallati prepared the following table;


Table XVII

RELATION BETWEEN AGE AND THICKNESS OF CORTEX AND NUCLEUS


Age of Subject (Years)

Cortex (Per Cent Increase)

Nucleus (Per Cent Decrase)

16 - 19

0.178

0.822

20 - 29

0.207

0.793

30 - 39

0.25^

0.744

ON

1

0

0.287

0.713

50-59

0.309

0.691

60 69

0.319

0.681

H

00

1

0

K

0.329

0.675


Vogt found that the axial cortical thickness (anterior and posterior) at the end of the second decade and during the third, comprises a much smaller part of the total lens thickness than in the later decades, and that the axial cortical thickness steadily increases in extreme age. At the same time, the nuclear thickness becomes less in relation to the total lens thickness, being more than four-fifths in



p


Fig. 369. A. Diagram illustrating the method of measuring the distance between zones of discontinuity. An illuminating lens of long focus is used: a-c, direction of the light beam; a-h, frontal plane on which segment (rfc, ed, dc) in the optic section are projected; b-c, direction of observation, b. Diagram of distances of the more important zones of discontinuity in the adult lens. The distances do not vary between the age of 20 and 40. A, anterior capsule; P, posterior capsule, Sa, surface of the anterior adult nucleus; Sp, surface of the posterior adult nucleus; Ea, surface of the anterior outer embryonal nucleus (fetal nucleus); Ep, surface of the posterior outer embryonal nucleus (fetal nucleus). The total estimated thickness is 4 mm. Each cortex (axial) is 0.6 mm.; adult nucleus is 2.8 mm.; embryonal nucleus (fetal and embryonal) is 2.3 mm. The thickness of the cortex (axial) in the young adult is oneseventh of the total lens thickness, while in older persons it is one-sixth.


1015


1016


BIOMICROSCOPY OF THE EYE


the second decade as compared to two-thirds in the seventh decade. He further showed that the increase in cortical thickness is not only relative but absolute by comparison with the thickness of the cornea (which is relatively constant) . In the young, the thickness of the cortex is somewhat less than that of the cornea whereas in adults its thickness is two or three times that of the cornea.

Relationship of the Morphology of the Lens to Its Function of Accommodation

In spite of the relative increase in thickness of the cortex during life, seen in the axial region, the lens maintains its flat shape. As already indicated, this is accomplished by the development of a complicated system of sutures. As the sutures elongate and branch, the abutting fiber ends broaden out; this can only be accomplished by a process of sagittal flattening of the fibers (anteroposterior). That this does not occur in the periphery (equatorially) is evidenced by the peripheral divergence of the zones of discontinuity in this region, signifying an increase in the total sagittal thickness of the layers between the stripes of discontinuity. The only exception to this is seen in the inner fetal nuclei, which are thicker axially than equatorial^ and in this sense retain their original more or less spherical (coffee bean) shape. Comparative anatomy illustrates the increasing tendency toward a flat lens (anteroposteriorly) as the phylogenetic scale ascends. In the lower series, at rest, in contrast to that of man, the soft homogeneous lens is spheroidal and accommodation occurs crudely by changes in position of the lens or by circular compression. In lower mammals (e. g., rodents) the lenses are spheroidal and have only a rudimentary suture system (i. e., a single line) while in higher mammals, a simple trichotomous suture is found, with the zones of discontinuity almost parallel and having little or no peripheral divergence. In the human newborn, the lens is not dissimilar to that seen in lower mammals. Its shape is somewhat spherical and just below the capsule are the simple three

This process (e.g., in birds) probably gives a greater range of accommodation at the expense of clearness, in contrast to the opposite effect arising from simple relaxation, as in mammals.


THE NORMAL 1.1-:NS: EIOMICROSCOPIC APPEARANCE 10J7


branched Y-suiurcs. I'rom ilien on the lens continues to grow by the interposition of new fibers below tlie capsule but at the same time, it becomes flatter anteroposteriorly. Undoubtedly the pull of the zonule is an important factor in this process. Biomicroscopically, observation of the zones of discontinuity and their peripheral divergence permits the ontologic as well as the phylogenetic development of an organ to be seen in the living for the first time. With relaxation of the zonule, during accommodation the anterior curvature of the lens increases (the radius of curvature according to Gullstrand is reduced from lo to 5 mm. and the anterior pole of the lens advances by 0.3 to 0.4 mm.) while the posterior curvature changes but little. In the absence of flattening no accommodation could occur. This is exemplified in spherophakia owing to the deficiency of Zonular tension, the elastic capsule containing the soft inelastic lens fibers tends to take a spheroidal shape, the lens assuming a condition of permanent and extreme accommodation. Evidently as the zonule relaxes, something occurs in the inelastic lens fibers to permit a thickening in the anterior axial parts of the lens. Gullstrand theorized that, owing to the speed of accommodation, fluid could not pass back and forth through the walls of the lens fibers and, owing to their inelasticity, their volume remains unchanged during the period when the zonule is relaxed. Hence he argued that the change in shape of the lens resulted from a change in relation of the radial fibers to one another within the lens (an intracapsular mechanism of accommodation).* Contrary to this idea of shifting (and even interposition) of the fibers, Vogt believed - on a sounder morphologic basis - that the fibers change their shape, and that during accommodation a shifting of their contents may occur in the direction of the axial region, with a resultant increase of cortical thickness in this area. As an analogy he cited the thickening in fibers of striated muscle. The fact that peripheral divergence decreases during the act of accommodation bears out his hypothesis that an axialward shifting of the lens fiber contents occurs.

static are fixed at both ends and probably have a cement sub of th^ ^ ^^en them, Gullstrand believed that during accommodation the fibers in the plane equator change their position in the direction of the lens axis.


1018


BIOMICROSCOPY OF THE EYE


The exact role in accommodation exerted by the so-called "sclerosis” or hardening of the nucleus, an apparent physiologic manifestation of adult life, is not entirely understood. Although not sufficient to affect vision, comparison of the central parts of the lens in the young with those of normal adults reveals in the latter a slight increase in relucency and opalescence. f Undoubtedly this increasing hardness in the nongrowing' part of the lens acts to stiffen it, a condition that militates against the act of accommodation, save for the fact that this condensing process gives more room for the growth of the softer cortex. Evidently, at least until presbyopia sets in, the effect of the process of condensation of the nucleus in retarding accommodation is compensated for by the progressive flattening of the lens. As Vogt has pointed out, although sclerosis lowers the range of accommodation, the hardened nucleus is important for the maintenance of transparency of a large part of the lens during age. Pathologically, it resists the effects of noxious agents much better than the younger cortex to which falls the mechanical task of intracapsular deformation (accommodation). The sclerosed nucleus reacts to changes by becoming uniformly cloudy (nuclear cataract), a condition which as a rule is not as serious to vision as cortical disintegration and degradation characterized by the formation of completely opaque material.

Modifications Associated with Aging

As already mentioned, the accident of birth, onset of puberty, or approach to adult life does not interfere with or cause any sudden visible alterations in the ordinary predetermined life cycle of the lens. The physiologic aging of the lens proceeds in an orderly way, conditioned by the special racial as well as by individual genetically determined forces. Certain of the so-called "senile” changes may

- The term "sclerosis” is employed to designate a condensation or hardening (lack of elasticity) rather than opacification. When the nucleus becomes opaque in the sense of a cataract, it is known as a "nuclear cataract.”

f Actually in the verj’ young the narrow beam will show that the relucency of the cortex is somewhat greater than that of the nucleus. This difference may result from the greater anatomic and optic homogenity of the nucleus.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1019


appear earlier in life (abiotrophy) and even though they are hereditary they may be organ specific and not general. Examples of this kind of change are met with every day, e.g., premature graying of the hair, arcus senilis, pinguecula, and presenile and typical senile cataractous changes. The list of examples could be continued indefinitely and could include innumerable illustrations indicating hereditary tendencies toward premature aging apparently localized to certain organs or systems of organs (skin, blood vessels, etc.). Some of these changes are .harmless, others interfere with vital processes and may lead to premature extinction of the individual. In Vogt’s studies of identical twins, the symmetrical and uniform appearance of certain senile changes in each pair seems to provide incontrovertible evidence that these alterations are genetically determined. However, the effects of exogenous factors (e.g., nutrition) cannot be entirely denied, but in some cases even these may be gentically determined (e.g., certain endocrine disturbances). The ramifications of this subject would take us too far afield. The following list includes the senile changes which, from the standpoint of biomicroscopy, do not necessarily lead to a degree of opacification warranting the term "cataract.” (Alterations, such as lamellary separation, widening of the sutures, water-clefts and types of "presenile” opacities more intimately associated with cataract, will be dealt with in a special chapter.)

1. Certain capsular (graining, spherules of the shagreen) and subcapsular changes

2. Increase in cortical thickness and its association to lens flatness

3. Increase in visibility of zones of discontinuity and suture systems of the cortex and adult nucleus

4. Increase in internal dispersion or optic density of the cortex and the nuclei (as seen in optic section)

5. Formation of the adult nuclear relief

6. Increasing yellowish coloration in the posterior cortex and posterior adult nucleus


1020


BIOMICROSCOPy OF THE EYE


Physiologic Remains of the Tunica Vasculosa Lentis

These rests are included in this chapter on normal lens findings rather than under the heading of congenital anomalies because biomicroscopically, evidences of them are found in varying degrees in the posterior lens capsule of every eye. In a sense their presence cannot be considered any more anomalous than the finding of a fetal nucleus in every normal lens. With the exception of rare cases of extensive pupillary membranes these rests do not interfere with vision. The forms of residua of the tunical vasculosa lentis are enumerated in the following classification.

I. Remains of the tunica vasculosa lentis r'"

A. Tunica vasculosa anterior

1. Pupillary threads and membranes

2. Starlike (usually pigmented) figures

3. Retro-iridal pigment lines and stripes

B. Tunica vasculosa posterior

1. Whitish figures and strands

2. Remains of the hyaloid artery (hyaloid corpuscle and vessel) strand

II. Remains at place of insertion of hyaloid canal; arcuate line.

REMAINS OF THE TUNICA VASCULOSA LENTIS ANTERIOR

As discussed on page 959 the vessel net of the tunica vasculosa lentis anterior (pupillary membrane) is derived from the branches of the main trunk of the hyaloid artery (vasa hyaloidea propria and the capsulopupillary vessels) .f Later branches from the ciliary vessels also supply the pupillary membrane. The double source of blood


Retrolental fibroplasia in premature infants will be discussed in the chapter dealing with anomalies of the vitreous, page 1392.

tThe lateral or capsulopupillary vessels are derived from the netnmrk forming the posterior portion of the tunica vasculosa lentis and extend to the equator of the lens where they anastomose with annular vessels. After the annular vessel is obliterated, the capsulopupillar)’ vessels anastomose into the anterior arcades of the choroidal net. Buds from the annular vessels form the anterior tunica vasculosa lentis, the central part of which later is designated as the pupillarj' membrane. Eventually the ectodermal extension (future posterior surface of the iris) of the optic cup separates the primitive pupillary membrane from the capsule. As the iris develops branches from the ciliarj' vessels also enter to supply the pupillarj' membrane and tlie deeper iris layers.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE' 1021

supply to the pupillary membrane and the arrangements of this system helps to explain the origin of many of the rests as well as many other severe anomalies seen in postfetal life.

Persisfenf P 7 ipillayy Threads and Membranes. The pupillary threads and membranes (already referred to in Vol. I, pages 569-570 and Vol. II, page 755) frequently adhere to the anterior capsule of the lens. These membranes or threads are often connected with the iris frill (an important but not absolute differentiating point between them and inflammatory membranes, the latter more commonly being connected to the pupillary border) , and either singly or branched extend over the pupil to be attached to the capsule. (See Vol. I, Plate XXXVIII, figs, i, 2, 3, 4, 5, 6.) When they are delicate and white in color, which is usually the case in light colored irides, their attachment to the iris frill may be difficult to follow unless the pupil is dilated. In brown irides these threads tend to become pigmented and even the delicate ones may be brownish or at least have pigmented spots on them. At the point of attachment to the frill, they may thicken and fan out considerably forming well-developed brownish bandlike structures. Since the pupillary membrane is not pigmented in the fetus pigmentation obviously must occur later. Both filaments and stars (discussed later) are more prevalent in younger persons. Koby investigated 500 eyes for the presence of filamentous remains and epicapsular stars; they occurred at a more or less constant rate up to the fortieth year and from that age on, the frequency gradually diminished (although the stars tended to be the more persistent) . In Koby’s series, there were filaments or stars in 223 eyes examined, and both were absent in 277. Stars alone were found in 79 cases; stars and filaments together in 26. Although the filaments are quite elastic, it seems probable that pupillary activity ruptures them sooner or later; this would account for their infrequency in the older age groups.

Ordinarily, filaments and stars do not affect vision; however, on rare occasions a case will be seen in which heavy filaments are associated with a dense carpet of pigmented stars in the pupillary area. In one instance where this occurred bilaterally in a qo-^'^ear-old man


1022


BIOMICROSCOPY OF THE EYE


the vision could not be improved beyond 20/50 O.U. (See Vol. I, Plate XXXVIII, fig. 6.) In this case there were no pigment or other deposits on the posterior corneal surface. At times the attachment


Fig. 370. Small starlike pigment deposits on the anterior lens capsule.

of the filament to the capsule is marked by the presence of a small whitish opacit)'^ not unlike the hj'^aloid corpuscle of the posterior capsule. Whitish thickenings (sometimes pigmented) may also occur anywhere along the course of the filaments but are more pronounced where the filaments join the frill. As Vogt has pointed out such thickenings or condensations may correspond to the WoMin bodies seen in the periphery of normal irides (page 756). Persistent pupillar}'^ membranes also may be associated with anomalies such as colobomas and anterior polar cataracts, ectopia lentis, and spherophakia.

Starlike Figures. Numerous authors (Bruckner,®*^ Stahli, Kraupa,"^^ Koeppe,^”'’ Koby,"”^ and Vogt) have studied and described these figures on the anterior lens capsule in great detail (Fig. 370). Generally, they are located in the pupillary area but occasionally may be found peripherally also. Stars are found unilaterally or bilaterally. They usually are arranged in one or more groups, sometimes in the form of columns or chains; in the rare instances in which they are densely packed, the} may form a mat (Vol. I, Plate XXXVIII, figs. I, 2 , 6). Their color usually corresponds to the color of the iris and may vary from dark brown to yellowish white. The characteristic shape of each star may be seen by high power. It may have three or four "points” with long tapering ends. The edges of the star between the points are concavely arched. Instead of being delicate and with three or four points, the mass may be clumped


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE .1023

with only a suggestion of one- or two-pointed processes or conversely the processes may be more numerous and spindly, resembling the spines of a burr - the longer spines tending to anastomose with


Fig. 371. Retro'iridal lines (nonpigmented) .


neighboring ones. The stars vary in diameter from 20 to 60 p. Koby has stressed the opinion that unlike the persistent threads, “the epicapsular stars are embryonic or fetal relics without any special relation to the pupillary membrane.” Originally, it was held that all pigmented stars were fetal rests and that clumps of pigment were of inflammatory origin, but it is now known that starlike deposits may be found also following inflammation and trauma (Plate LXXIII, figs. I, 2,’ 3, 4, 5, 6).

Keiro-iridal Vigmented Lines and Stripes. These radiating grayish and pigmented lines and stripes on the peripheral parts of the anterior lens capsule were described by Vogt. Because of their delicacy and their peripheral location they have been overlooked. Wide dilatation of the pupil is necessary to see them. They are only visible in direct focal illumination with medium and high powers of magnification. They occur in normal eyes with no evidence of inflammation


1024


BIOMICROSCOPY OF THE EYE


and hence are not to be confused with the coarser pigmented deposits, which may also assume an irregular radial disposition, being derived from the furrow system of the posterior surface of the iris (page 846) following iritis. Vogt has termed these structures retroiridal lines because he believed that they were rests derived from the retro-iridal part of the fetal anterior vascular tunic of the lens."' The appearance of these lines and stripes varies from case to case; sortie are composed of very short radiating lines of pigment, usually from 0.05 to 0.5 mm. in length, the longest reaching to i.o mm. With higher powers it will be seen that the lines are formed of fine pigment dots. In other cases, whitish lines or even broader pyramidal bands (apices pointing axiall)r) may be found with or without occasional pigment grains. At times the axial ends of these whitish stripes and lines appear feathery (Fig. 371). In Vogt’s series these lines and stripes were located more commonly on the nasal side and were stationary. I have seen them several times temporally situated as well, in older persons whose eyes showed no signs of inflammation. In one case especially there was senile atrophy of the pupillary margin. Since then I have observed these lines in younger individuals with no signs of iris atrophy. Recently Bellows reported three instances of the presence of these retro-iridal lines.

REMAINS OF THE TUNICA VASCULOSA LENTIS POSTERIOR

The biomicroscope reveals evidences of uniformly gray or whitish rests on the posterior lens capsule and in the anterior or hyaloid portions of the retrolental vitreous, in practically every normal eye. These structures, seen so universally with this method of examina

It was only after he found (in three cases) that some of these lines were in continuity with the remains (threads) of the pupillar)' membrane tliat Vogt was convinced of their origin. In one case, typical retro-iridal pigment lines extended axially in branching tracts of pigmented stars. Only the remains of the anterior vascular tunic are pigmented (the remains of tlie posterior tunica - on the posterior lens capsule - are always unpigmented except in inflammations). This may result from the fact that both parts of this anterior tunic, peripheral and central (pupillary membrane), receive blood from the ciliary vessels as well as from the posterior hyaloid system. The posterior tunic is derived solely from the branches of the hyaloid. Vogt has called the peripheral portion of the anterior tunic (the capsulopupillary part) the "retroiridal tunic” because of its location and differentiates its rests from those of the pupillary membrane by the fact that in the former they are seen as stretched radiating lines, whereas in the latter they are found in the form of threads and stars.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1025

tion, are not seen with the ophthalmoscope, with the possible rare exception of the hyaloid corpuscle (the so-called "spurious posterior polar cataract”) when strongly developed it may cast a shadow


Fig 372. Remains of the tunica vasculosa lentis posterior and unusually prominent twisted

remains of the hyaloid vessels.


posteriorly. With the arc lamp, the visibility of these structures is enhanced and in many cases numerous smaller ones, not seen by means of the ordinary nitra lamp, appear. Corresponding to the nasal position of the optic papilla, the location of these remains (tunica posterior and the insertion of the hyaloid canal) on the posterior lens capsule is not at the posterior lens pole but from 1.5 to 2 mm. nasally and slightly below as described previously anatomically by Seefelder.'l* Physiologically their presence at the pole.


This structure was first seen ophthalmoscopically and correctly described by Mittendorf and has been referred to as ' Mittendorf’s dot,”

t The central hyaloid vessels begin to regress m the eighth month of fetal life and lose their continuity with the vessels of the disk but still retain their connection to the lens The distal or lens parts gradually cull up At birth the main trunk may still extend backward but within the first few years it gradually takes a dependent position and is seen at times as a colled cord attached to the lens with its free end hanging loosely



THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1027

especially if overdeveloped (from the failure of normal regression), would tend to interfere with central vision. Morphologically the shape and extent of these rests vary from case to case and even in

ri\

Fig. 374. Forms of hyaloid corpuscle.


each eye (although in the case of the latter they tend to be similar) , but biomicroscopically some residua are always found. In order to see them it is best to localize the posterior A fetal suture because they lie behind it on the posterior capsule. If the beam (optic section) is directed from the temporal side, it will be seen that, as the angle between illumination and observation is narrowed, the distance between the posteriorA-suture and the posterior capsule stripe seems to decrease. With the patient’s gaze directed slightly nasally, it will be seen (when in sharp focus) that the rests lie on the posterior capsule nasally to the main sutural forking behind' the A, or in other words usually just behind the upper subbranch of the lower nasal arm. If the mirror reflex comes into view at this point, it can be moved nasally and out of the way by having the patient direct his gaze still more nasalward. With experience the observation of this area becomes almost automatic.

In this area three distinct types of remains are found (with variation) . However, they are not always seen fully developed in every eye, nor are all of them always present, (i) Delicate gray-white lines forming an irregular net or whorl. They may be fixed to the capsule throughout their extent or attached in parts; their ends may


1028


BIOMICROSCOPY OF THE EYE


float freely behind it. (2) The hyaloid corpuscle which may or may not have a twisted vessel cord or branches attached to it (partially free or attached). (3) The arcuate line, rarely a complete circle, commonly is seen as a crescentric figure on the posterior capsule nasally to or between the overlying posterior Z-suture and the place of insertion of the vessels, its concavity facing the latter.

Whorl-like Keiucihis. An exact description of the innumerable varieties of figures or designs formed by the whorl-like distribution of these delicate vessel-remains (which, according to Vogt measure from 0.03 to 0.06 mm. in thickness) would be too time consuming and laborious. The accompanying illustrations will give some of the forms ordinarily seen (Figs. 372, 373, 374). In some cases these structures are seen in the form of rings while in others they are curled.

The free-floating (nonfixed) curlicue or spiral line always seen first by beginners hangs verticall}'" downward in the so-called “retrolental space” (anterior or hyaloid parts of the vitreous) Its attachment to one of the whorl-like convolutions of the fixed remains can usually be traced. With movements of the eye this nasally situated coiled line can be caused to snap Hke a whip, though more slowly. In some cases it may attain a length of several millimeters, extending deep or peripherally so that its terminal end will not be seen. Frequently small whitish spots or condensations occur along the course of these fibers. As a matter of fact, these spots are found on all the threadhke remains, especially on those in the anterior part of the vitreous. This curled structure (occurring in over 50 per cent of young people), which is much more commonly found than the corpuscles, becomes less frequent with age, either due to atrophy or as a result of being torn off. On the posterior lens capsule itself, it is rare to see an}’" markings of rests except in the nasal area above described. However, in rare instances ring-shaped markings have been described on the posterior lens capsule in the far periphery. In one case (Hudson) the ring was found midway between the axis and the periphery. It was composed of a row of gray dots. In other cases

These, similar to the hyaloid vestiges seen deeper in this area not attached to the lens, are easily visualized because the surrounding darker or less relucent vitreous offers better contrast than the normal opalescence of the posterior capsular stripe.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1029

when located far in the periphery, it was formed of nonstellate amorphous brown pigment. According to Ida Mann this may result from the maintenance of contact between the tips of the ciliary processes and the lens for too long a period.

With the pupil widely dilated as described above, numerous branching fibers may be seen peripherally in the anterior vitreous (not connected to the lens) which evidently are derived from the vasa hyaioidea propria. Embryologically these peripheral branches of the artery are the first to show signs of regression. As early as the 6o-mm. stage they tend to lose their connections to the main trunk of the hyaloid artery so that their free curled ends hang loosely in the vitreous, but distally they remain connected to the vessels on the posterior surface of the lens. The tendency to curl after separation is accounted for by their elasticity and, as noted above, is a feature of the large central branches and even of the main trunk.

The Hyaloid Corpuscle. These are densely white, more or less solid spherical structures, varying little in size and were formerly known as '‘cataracta spuria” (Fig. 374) . They are located on the posterior capsule (where they frequently mark the attachment of the remains of the curled freely floating hyaloid vessel) or at times on the ends of floating remains behind it in the retrolental space or vitreous; those having an attachment to the posterior capsule are fixed while those attached to the mobile hyaloid vessel remnant move. The former are more common while the latter present a more striking picture. When very far back in the vitreous, they may even be visible ophthalmoscopically. In these cases they may only be discerned biomicroscopically when disturbed by ocular movements. Although, commonly, these opacities appear to be solid, spheroidal corpuscles, occasionally flattened discoidal bodies may be found. Vogt examined 82 children and found 7 who had corpuscles. In a study of 100 children (normal eyes) between the ages of 10 and 14 years, I found coipuscles m ii cases. It may be considered that their frequency is of the order of 10 per cent in the young.

The Arena fe Line. In 1919 Vogt'^"" first described the so-called aicuate line, which according to its degree of arc incompletely 01, less often, completely - surrounds the rests of the trunk and


1030


BIOMICROSCOPY OF THE EYE


the main central branches of the hyaloid vessels on the posterior lens capsule. Most often it appears as a whitish crescentric line, temporal to the place of insertion of the hyaloid vessels, or about half way between the area of insertion of the hyaloid vessels and the posterior pole of the lens (Fig. 373). It can be located easily by first focusing on the posterior X. The arcuate line will then be seen on the posterior capsule directly behind it. Its convexity faces temporally toward the suture. In certain cases another more nasally located arc will be seen together with the usual one, with the ends of each intersecting due to a difference in curvature (Fig. 373). When both are present, their concavities face one another, their ends either crossing or, more often, fading out without touching each other. It is ver} rare indeed to find that the location of the arc varies either temporall} (nearer to the lens pole) or nasally from its usual site. According to Vogt’s measurements, the width of the arc varies between 0.02 to 0.06 mm., and in a few exceptional cases up to 0.15 mm. The radius of curvature of the arc is usually about i mm. The ends of the arcuate line behave in different ways but usually gradually fade out above and below, the vertical distance between the ends being from 1.5 to 2 mm. At times the two ends are stretched out so that a parabolic or hyperbolic figure is formed. In describing its optical properties while changing the direction of the light, Vogt found that it could be seen both by specular reflection as well as by direct focal illumination. He stated that in some cases, on moving the light (so that the angle of reflection did not equal the angle of incidence) , he could cause it to disappear from view. This would suggest that the arcuate line protruded or was on a different level from that of the posterior capsule. In other cases, he found that changing the angle of the light did not cause the arcuate line to disappear. It is always seen in focal light, and hence its presence is not just a reflex resulting merel}'^ from a difference of level but rather is the expression of an opacity of the posterior lens capsule.’'"

In his studies of the optical phenomena of the arcuate line Vogt found that in a certain proportion of the cases it was possible to cause the arcuate line to disappear by shifting the angle of illumination. This would seem to indicate that in these instances the arcuate line is an optical manifestation of regular reflection brought about not by the presence of an actual opacity but rather by a difference in level on the posterior lens capsule at this place.


THE NORMAL LENS; BIOMICROSCOPIC APPEARANCE 1031

Rarely") fine lines from the concave side may be seen running to'ward the hyaloid insertion. Also the area just temporal to the arcuate line may be traversed by delicate lines running concentrically with the arc. Vogt has also described in two cases out of a series of 200 that the arc instead of being a continuous line was made up of small radiating striae.

The exact derivation of the arcuate line is still uncertain. However, recent research (especially in the light of the proved existence of vestiges of the hyaloid canal in the retrolental regions of animals and also on the basis of comparative biomicroscopic findings) , seems to indicate, according to Vogt, that the arcuate line which surrounds the area of insertion of the hyaloid vessels represents the place of insertion of the hyaloid canal. He points out, for instance, that the region, embracing the area of the insertion of the hyaloid vessels, and outlined by the arcuate line, in some persons appears darker than the outside surrounding regions.'*' On the other hand, it would appear that the anterior opening of Cloquet’s canal should be larger than that indicated by the curvature of the arcuate line. Ida Mann suggested that the line marks the place where the early perilenticular tunica fibrosa was attached to the lens, i.e., before it was separated by the ingrowing vascular network derived from the hyaloid vessels. The diameter of this area at the end of the second month corresponds better to that of the arcuate line.


In other cases, notwithstanding, in changing the angle of illumination the arcuate line was constantly visible. It would seem therefore that a definite opacity was present and was visible at any angle of illumination by diffuse reflection.

Koby states: "A curious phenomenon in illumination may lead to error. It happens that the corneal reflex lights a part of the mount of the objectives, and this is reflected in the cornea in such a way that a semilunar image is formed in the deeper parts of the lens. This image so closely resembles the arcuate line that it may be mistaken for it. Their catoptric images are recognized from the fact that when the beam is moved slightly, two exactly similar images of the twin objectives are seen, and in the middle of each there is a luminous point arising from the reflections of the light at the surfaces of the objective themselves.”

This corresponds to the condition found in dogs and rabbits in which a dark (optically less relucent) area outlined anteriorly by the arcuate line extends backward into the vitreous. Within this darkened area the remains of the artery can be followed dorsalward. Also the gray lines concentric with the arc line occasionally seen in man are in these animals accentuated, giving this area a greater relucency. Vogt believes that this is the place where a reflection or reversal of direction of the membrane-like layer occurs to form the wall of the hyaloid canal. These conditions are better seen in animals because of the greater opacity of the vitreous and because of the lesser tendency of the vitreous to make oscillator^' movements.


24 Developmental Lens Changes

24 Developmental Lens Changes

25 Presenile and Senile Cataract

XXV. Presenile and Senile Cataract

26 Complicated Cataract

XXVI. Complicated Cataract

27 Injuries to the Lens

This chapter includes discussion of traumatic lesions resulting from contusions and perforations, and the lens changes produced secondarily by retained intra-ocular foreign bodies (especially iron and copper) . Since biomicroscopically the picture of traumatic luxation and subluxation does not differ essentially from that seen in spontaneous (hereditary) displacements, both depending on pathologic changes in the zonule, they are considered together in the chapter on the zonule (page 1345) and on page 1206 under the heading of complicated cataract. In a great many instances the morphologic aspect of the changes provoked by the above-mentioned causes are so characteristic that it is possible today in many cases with the aid of the biomicroscope to differentiate them from other types of cataract. The value of accurately recorded biomicroscopic examinations in traumatic cases hardly needs to be emphasized here. One cannot, however, rely on the morphologic appearance of lens changes alone. In addition to a thorough survey both of the functional and ophthalmoscopic aspects, the biomicroscopist carefully examines the conjunctiva and sclera (for congestion, hemorrhages, scars, etc.),, the cornea, the anterior chamber (depth and flare) , pupil and iris and vitreous because it is rare that trauma sufficient to produce lens changes does not cause other changes, especially in the anterior segment. This holds not only for fresh cases, in which the history of an injury is incontrovertible, but it applies also to cases involved in medicolegal disputes years after a reputed injury. Again the importance of the use of the narrow beam for exact localization of lens changes should be emphasized. With the unfocused beam or even with the focused wide beam a pan

1235


1236


BIOMICROSCOPY OF THE EYE


oramic view of an opacity may be obtained, but exact localization is almost impossible. This is particularly important when it is necessary to know whether a change is located in the capsule or just below it. When emplo^dng the focused wide beam, angulated so that the mirror zone (specular reflection) lies partly over a subcapsular opacity, it may be possible to determine that the shagreen of the unaffected anterior capsule lies in a plane anterior to the lesion. But with the narrow beam the illuminated capsule and anterior band of disjunction (the latter cannot be seen with the broad beam) are seen as sharp lines and exact localization becomes relatively simple.

In most of the discussions on cataract due to trauma, the subject is considered from the standpoint of the presence or absence of capsular rupture. Cases in which even the biomicroscope fails to reveal any rupture of the capsule are called "contusion” cataract. They may follow direct or indirect blows to the eye, with or without evidence of rupture or perforation of the outer ocular tunic. The possibility of submicroscopic openings in the capsule in contusion cataracts has not as yet been disproved. Ruptures in the neighborhood of the equator in the absence of a coloboma, or even of the posterior capsule in the presence of extensive cataractous change, could elude biomicroscopic detection. The pathogenesis of traumatic cataract following frank rupture of the capsule (e.g., by the passage of a foreign body or by the penetration of sharp objects) in which the aqueous can gain access to the lens fibers through a gaping wound, is not difficult to understand. However, in contusion cataract where no apparent capsular perforation has occurred, the mechanism involved in its production is 'as yet not clear. Several interesting hypotheses have been advanced to explain the mechanical basis of the lens opacities seen in contusions.

Vogt drew a parallel between contusions of the eyeball and the skull (about which more is known). The outer wall of the eyeball is of course softer and more elastic than the bony skull. (The softer skull of the newborn and of children would perhaps offer a better comparison.) Hence when force is applied (but not of sufficient strength to cause an external rupture, or fracture) , its motion will be transferred to the Interior and will cause a shifting or "a gliding” of the contents. As a result of the acute increase of internal tension, the pressure effects (in the


1237


INJURIES TO THE LENS

case of the brain [Kocher] ) may set up a condition corresponding to commotio and at the same time may provoke a strong contusion in the direction of the blow. In the eye such effects as Vossius’ ring or Berlin’s edema may result. According to hydrodynamic laws, the contents of the skull and eyeball being considered as fluid, the effect of the force is transferred not only in the direction of the blow, but with equal intensity in all directions. Therefore, internal pressure develops which acts from the center peripherally so that the contents may be hurled against the wall; depending on the intensity of the external force, varying degrees of damage may result. In the eye this might result in tears of the sphincter, iridodialysis, capsular tears, luxation of the lens, tears of the retina and choroid. According to Vogt, in contusio bulbi the most important role is played by the "throwing motion” of specifically heavy parts. The specifically heavier iris will be pressed for a moment against the lens, thus producing Vossius’ pigment ring on the capsule. The lens can be broken loose from its zonular attachments and forced posteriorly into the vitreous. If the eyeball is ruptured, the lens may be extruded. In the posterior segment of the eye, the pressure of the vitreous may bore a hole in the macula and when the retina is thrown against the sclera, Berlin’s opacity can result. Although a considerable amount of the force is dissipated when an actual perforation occurs, still a wave of high pressure may also set up further damage in parts not in the direct line of the force. An example of this was seen in a case of a perforating injury when a Vossius’ ring formed.

Frenkel, who considered the effects of contusion in the anterior segment as a syndrome, believes that the motion imparted to the lens as a result of the force is the primary factor in causing the different alterations seen in the syndrome. Under the impact, the lens is pushed back against the vitreous (the zonule often being partially torn) . On the rebound it snaps forward and "distends the iris diaphragm like the head of a fetus against the neck of the uterus.” As a result (of the force?) of the recoil, damage to the lens and iris occurs. The following are the lesions of the anterior segment syndrome in the order of their severity: (i) paralytic mydriasis (isolated, often transient); (a)' internal ophthalmoplegia; (3) lesions of the iris - small pupillary ruptures, minimal iridodialysis (often not easily seen); (4) localized subcapsular opacities; (5) subluxation of the lens. In addition Frenkel calls attention to the following details which must be looked for carefully with the biomicroscope: (i) careful examination of the depth of the anterior chamber; differences of level is often the only sign of subluxation of the lens; (2) noninflammatory rests of iris pigment on the anterior surface of the lens (including Vossius’ ring); (3) localized lens opacities (which may be due to tearing of the capsule ? and penetration of aqueous [these opacities may be stationary or, rarely, may become progressive]); (4) a semicircular concentric fold of the iris. This sign is of importance in nonapparent subluxations of the lens.

Frenkel also differentiates between traumatic syndrome of the anterior segment in the case of direct action on the globe and traumatic syndrome of the posterior segment in the case of indirect action. It should be pointed out that the symptoms of anterior segment contusion are more conspicuous in adults than in the young.


1238


BIOMICROSCOPY OF THE EYE


This has been explained by the suggestion that in the young, owing to the greater elasticity of the iris and molding power of the lens, the brunt of the contusion is more likely to be borne at the retinal-zonule insertion than at the lenticularzonule insertion.

Other authors have suggested that the cause of contusion cataract lies in fact that owing to either alterations in the capsular epithelium directly or variations in osmotic pressure of the aqueous, fluid gains entrance into the lens. The fact that rosette-shaped opacities are so common leads to the opinion that the suture system of the .cortex is the locus minoris resistentiae (Vogt) .

Contusion Cataract

That certain characteristic types of lens opacities are peculiar to nonperforating contusions (some of which were described before the days of biomicroscopy) is now generall)^ agreed. Biomicroscopic examination, however, has been of immeasurable value in confirming previous impressions, because b} its means not only can the lesions be seen better, but what is of greater importance, they can be accurately localized and differentiated from opacities due to other causes. In addition it is possible now to follow accurately the progress of the lens changes and to note minute details of their morphology. It is known that in certain cases delicate opacities (probably due to edema) appear immediately after a contusion and may later disappear - in other words, they represent reversible phenomena. However, in most instances the opacities resulting from contusions are permanent but nonprogressive, although in the case of the subcapsular alterations, their localization may change. Localized opacities in the subcapsular region (the most vulnerable part of the lens - see cataracta complicata) can be displaced deeper into the cortex b}'^ the ingrowth of new fibers (Vogt) .

As alread}'^ mentioned, the biomicroscope also assists in detecting


Davidson®^ states: "The importance of the use of the narrow beam and of retroillumination cannot be too much stressed. It has served to rectifj^ some previously held notions. It shows a much greater rarity of posterior-capsule ruptures, an intactness of the equatorial capsule when accessible to examination in colobomata, and draws our attention to the biochemical factor alongside the mechanical factor of microscopic solution of continuity, in the production of a contusion lens opacit}^ It has also established the difference betv'een contusions in the young and in the adult in their effect on the lens. It has demonstrated that an opacitj- has the tendenq' to traverse the equator backv^ards along the same discontinuity surface or zone, and that zonular, coronary opacities and riders and other cortical opacities can be obser\’ed in contusions.”


1239


INJURIES TO THE LENS

confirmatory signs of trauma especially in the iris and vitreous, the importance of which has been pointed out by Frenkel. Besides the more characteristic traumatic lens opacities, e.g., Vossius’ annular (ring) opacity and the traumatic rosette opacity, forms identical to typical presenile and senile lens changes (cortical punctate, lamellar and zonular, coronary, cerulean, nuclear and posterior saucer opacities) have been described and attributed to the effects of contusion. Such an assumption must be valid in the face of incontrovertible history of injury, signs of anterior contusion syndrome (more common in older persons) and provided the lens in the uninjured eye was unaffected - since ordinarily, when of developmental origin, these forms tend to be bilateral, Davidson has also pointed out that injury may activate the progression of pre-existing presenile and senile cataractous changes. As with complicated cataract from other causes the morphologic appearance of contusion cataract may depend on the age of the individual. So that in the aged, whatever the cause, the resulting lens opacity may resemble that of developmental senile cataract. This point, against which there seems to be no a priori objections, requires further confirmation; if further verified, it would be of great importance in medicolegal cases. From an analysis of 57 eyes with contusion lens opacities (in persons of varying age) Davidson indicates that the typical or characteristic types of contusion opacities, i.e., capsular (Vossius’ ring opacity), subcapsular (nondistinctive or rosette forms) , equatorial (lamellar) and posterior-lens involvement-tendency, and regional segment-like localization are morphologically specific for the young. After 45 years of age senile pathologic changes intervene and hence the specific morphology of contusion cataracts after this age becomes less discernible. That such variations should occur is conceivable when one considers the variances in the morphology and development of the lens during life. But as Davidson states: "Any generalizations in regard to specific morphologic picture of contusions of the lens at different age periods must, in the nature of things, be regarded as provisional.” In the end one must always consider that the natuie and foice of the blow varies in every contusion and that as


PLATE LXXV


Fig. I, Vossius’ ring. Diffuse illumination.

Fig. 2. Contusion cataract. Partial rosette seen twelve years after an injury. Diffuse illumination.

Fig. 3. Same case as shown in Figure 2. Showing deep location of rosette. Late Remotio. Direct focal illumination. Optic section.

Fig. 4. Rosette opacity after perforating injury near the limbus.

Fig. 5. Optic section, same case as shown in Figure 4. Direct focal illumination. Optic section.

Fig. 6. Lamella type of opacity following contusion. Note subcapsular location of the opacities.


1240


1243


INJURIES TO THE LENS

yet no definite relationship between the degree of force and its results have been established.

The lens opacities, characteristic of contusion, are listed below (it should be remembered that many of them may occur in cases in which the capsule has obviously been ruptured, e.g., perforating injuries) :

1. Vossius’ annular (ring) opacity

2. Disseminated subcapsular opacities (Vogt) and their later displacement. Also "button-shaped” opacities (cataracta nodiformis

3. Traumatic rosette-shaped opacity (recent and late [remotio cataractae traumaticae] )

4. Lamellar opacity (zonular)

5. Presenile (coronaria and cerulea) opacity

6. Progression of previously existing senile opacity

7. Posttraumatic atrophy of the lens (Vogt)

vossius’ annular opacity

In 1903 Vossius described the finding of a ring-shaped pigmented opacity on the anterior surface of the lens following trauma to the eye. In outline the ring runs concentrically to the pupillary margin and generally can be seen in the red fundal reflex ophthalmoscopically. According to Vossius the mechanism by which the ring is formed corresponds to the imprint by a rubber stamp ("Stempelabdruck”) . In other words, owing to the effect of the transmitted force, the posterior pigmented surface of a portion of the iris is pressed against the lens and leaves an imprint (Plate LXXV, fig. i). This means that the ring is formed at the instant of the contusion and that it is not formed by a later deposition, e.g., from pigment in the aqueous. Many of its morphologic and physical characters substantiate this opinion. The ring has been seen almost immediately after contusion. With lapse of time, instead of increasing in size or prominence, it tends to absorb. This has been noticed even when a hyphema has been present for long periods of time. It is true that pigment may be deposited on the anterior capsule in ring


1244


BIOMICROSCOPy OF THE EYE


form even in latent iridocyclitis, but in this instance there are morphologic differences: The width of the ring is narrower; the pigment coarser (clumps) and isolated particles are seen peripheral to the ring upon dilatation of the pupil; and usually remains of whitish exudates are found on the capsule to which pigment is frequently adherent.

Biomicroscopically, Hess and, later, Vogt showed that the Vossius ring does not represent an actual opacity of the capsule or lens substance but that it is the result of. a thin deposit on the surface of the anterior lens capsule. The ring itself consists of a flat (single) layer of fine pigment granules, usually of a reddish brown or bronze color, often glittering. Depending on the intensity of the light,'*' the visibility of the ring will vary when observed in the mirror reflex of the anterior capsule. With the lowering of the intensity of the light the shagreen becomes hidden by the ring as the latter passes over it and, conversely, if the intensity of the light is strong with consequent increase in brilliance of the shagreen, the fine granules of the ring may be obscured. The single-layered and flat disposition of the pigment particles (adherent to the capsule) disputes any secondary accumulation, which might be expected if the pigment were deposited or precipitated from the aqueous as in inflammations or hemorrhage. With higher powers of magnification, 40 X or more, the concentration of pigment granules is seen to lessen in the direction of the axial and peripheral edges of the ring where their distribution also becomes more irregular. Frequently the ring is not continuous but rather appears to be more or less regularly interrupted or segmented. Here and there small dark gaps or holes (pigment free areas) will be seen. This appearance has been explained by the fact that the posterior surface of the iris (page 734) normally is not smooth but is composed of closely contiguous radial ridges. Law stated that he had never seen a case of Vossius’ ring opacity that did not clear completely and permanently.®^®

In a case measured by Vogt the over-all horizontal diameter of the ring measured 3 . 5 mm. ; temporally the width of the pigment deposit

Governed by the width of the beam or by altering the rheostat.


124S


INJURIES TO THE LENS

was 1.22 mm. while nasally it was 1.25 mm. Above and below its width varied between these two measurements. According to Vogt it is not clear why the same type of contusion produces a ring in one case and not in another, and why it is seen only in the young and not in the aged. In the latter case he feels that some role must be played by anatomic factors peculiar to the young (softness and elasticity of the tissues) . Both Hess and Zentmayer have cited cases to prove that the ring was formed secondarily to hemorrhage in the anterior chamber and its presence is not necessarily conditioned by an antecedent contusion. Vogt stated that he had never observed Vossius’ ring formation in cases of nontraumatic anterior chamber hemorrhage. After traumatic injury, blood and pigment may be present in the anterior chamber for a long time, but the ring always appears most intensely on the first day of its observation, and in spite of the presence of blood, the deposits forming the ring tended progressively to disappear. Also, in stressing the fact that the ring develops immediately at the time of injury, he brings out the point that double or multiple ring formation has never been seen after the original one developed. This speaks against a later deposition from pigment or blood in the aqueous. This should be possible if, as postulated by Hess, the deposit consisted of blood pigment. He explained the ring formation as resulting from sweeping together of the blood cells by iris movement. Hence, upon dilatation of the pupil (either secondary to sphincter lacerations or mydriatics) theoretically a second ring could form. In addition, with high power the dark reddish-brown color of the pigment granules of the ring can be noted. One gets the same color impression of the dark iris when examining it under high magnification. Under the same conditions blood cells appear pale yellow.

In explaining the pathogenesis of the ring Vossius stressed the following points: (i) compression of the cornea; (2) desquamation and adherence of the pigment epithelium; (3) degeneration of capsular epithelium and at times also of the underlying lens fibers. Frenkel objected to this viewpoint of Vossius and to that of Wageman and others (i.e., depression of the cornea, displacement of the


1246


BIOMICROSCOPY OF THE EYE


aqueous, and distention of the sclero-corneal ring) . According to this author the sequence of events in the formation of the ring is: (i) rupture of the zonule; (2) subluxation of the lens; (3) forcing of the lens against the vitreous; (4) rebounding action of the lens against the posterior surface of the iris. Frenkel contends that the zonule is not as easily stretched as is commonly believed but that to the contrary it tears more easily. His idea of the rebounding action of the lens ■would certainly explain those cases (Steiner, 1910;**^® Purtscher, 1913 in which a ring formed in consequence of intraorbital extra-ocular bullet lesions causing compression of the globe.

TRAUMATIC DISSEMINATED SUBCAPSULAR OPACITIES (vOGT)

Thin, flattened flakelike or punctate opacities layered or irregularly distributed in the anterior parts of the lenticular cortex may occur as an early or late manifestation of injury (Fig. 435 B) . These opacities are usually discrete and tend to be stationary; but later, owing to the growth of new lens fibers, they may be pushed somewhat deeper into the cortex. This is attested by the fact that recent ones, which seem to be attached to or to lie just below the capsule later, become separated from it by a layer of clear lens substance. This fact gives confirmation of the continuous growth of the lens (see Polar Cataract) . The genesis of the zones of discontinuity and the development of the intervening layers has always been a baffling problem. In the normal lens with the ordinary nitra light source the uniform opalescence of the layers on both sides of the demarcation line deprives the observer of any means of following the shifting and rearrangement of the different layers which are bound to occur during growth.

The presence of a localized traumatic cataract offers another approach to the problem of lens growth. These opacities and also the larger rosettes, which are usually thin and sharply defined, can be accurately located with a narrow beam, and since they change not at all or very little in size and shape, any alteration in their location can easily be followed. In the beginning such opacities are situated immediately below the capsular epithelium and later will be


1247


INJURIES TO THE LENS

seen pushed deeper and deeper by newly formed lens fibers. The two landmarks for the observation are: (i) the disjunction line; (2) the adult nuclear band. With this method it is possible to determine (by comparison with the normal fellow eye) if the trauma has been strong enough to interfere with the production of new layers, or to abolish their production entirely. In some instances, as the opacity migrates deeper, tags of it may remain adherent to the capsule, thus offering a confirmation of the interpretation just mentioned.

Vogt first observed traumatic disseminated subcapsular opacities in 1922 in the left eye of an 8 -year-old boy. This eye had been struck by a chestnut two years previously. At the time of the injury there were ruptures of the sphincter and blood in the anterior chamber. The blood disappeared the following day and a typical Vossius’ ring was present. At this time there were no cortical opacities. Two years later, on reexamination, there were numerous white punctate opacities irregularly scattered in more or less the same level with and below the anterior line of disjunction. Vossius’ ring was no longer present. The uninjured eye did not show any changes. In this case Vogt considered the opacities to be a late manifestation or secondary complication of the ring. In another case similar opacities were seen in association with a Vossius ring, nine days following a contusion. Three years later the punctate opacities not only persisted but were slightly increased in number. In one case there was a limbal rupture with prolapse of the iris, which was excised. Ten days later in the area of the coloboma numerous small white dots were seen subcapsularly. They did not follow any orderly or radial arrangement, a condition noted by Foster in his report.^^® At times coalescence of the flakes may result in a thin flattened continuous layer of opacity with radiating processes (opacities and vacuoles)

Some resemblance can be found between this method and the method used by geologists to study the movement of glaciers. In the great expanse of ice and snow it is impossible to tell whether there is motion or not. By choosing an immovable landmark like the pinnacle of a mountain and placing an easily recognizable object like a black rock on the glacier the distance between these tw-o can be measured at the beginning of the observation and throueh the years, and so, the motion of the glacier can be found and recorded



1249


INJURIES TO THE LENS

having an appearance somewhat like the nontraumatic anterior complicated cataract caused by intra-ocular disease.

A very interesting and hitherto rarely mentioned type of trau


Fjg. 435. D. Cataracta nodiformis, diffuse iHumination. e. Same case as in n, optic section.


matic subcapsular opacity is the so-called "button-shaped” form (cataracta nodiformis) . They appear studiike (collar-buttonshaped) , rounded, and layered, not unlike small, pyramidal, polar cataracts. Their color is whitish and they tend to develop some time after the injury has occurred. In the case illustrated by Figures 43 5 A and C the buttons were first noticed two years after a perforating injury. On the day following the injury prolapsed iris tissue was excised. Two weeks later a flattened lamellar opacity was seen in the neighborhood of the coloboma (Fig. 435 A). This did not progress.

When frank signs of previous inflammation (e.g,, keratic precipitates or synechiae) are absent, as might be the case in latent forms of iritis or cyclitis, and in the absence of a history of trauma, differential diagnosis may be very difficult. Ordinarily, in compli


1250


BIOMICROSCOPY OF THE EYE


cated cataract the tendency to deeper displacement by clear lens fibers with time does not occur. Whereas complicated cataract tends to progress, localized contusion opacities, in contrast, are stationary or even regress. In the region of the larger flattened forms of subcapsular traumatic opacities the total depth of the cortex may be thinned considerably (lens atrophy) .

Davidson has also drawn attention to such forms of lens opacity and has stressed their medicolegal importance. Nothing is known concerning the pathogenesis of these small traumatic flakelike or punctate subepithelial opacities. They are very similar to those seen following acute attacks of glaucoma. In the latter case actual ruptures of the capsule would be doubtful. In both traumatic injury and glaucoma localized damage to the capsular epithelium resulting from suddenly increased intra-ocular pressure seems a more probable explanation of their origin.

EARLY AND LATE TRAUMATIC ROSEITE-SHAPED OPACITY

Probably the most distinctive form of cataract associated with trauma is the so-called “rosette-shaped” opacity. This type of lens opacity is seen in both nonperforating (contusion) and perforating (penetrating) injuries of the globe. Rosette-shaped opacities associated with perforating and penetrating injuries will be considered under the heading of perforating injuries to the lens. Those seen immediately or shortly after injury are located just below the anterior or posterior capsule (or both) and are known as the fresh type (Fig. 436). The late or delayed traumatic rosette cataract (remotio cataractae traumaticae) frequently discovered years after an injury, is situated deeper in the cortex or adult nucleus, and is separated from the capsule by lucid lens substance. It is believed that in these cases the damage occurs to the subcapsular fibers at the time of injury, but the changes are not noticed until years later when they become more opaque. At this time, owing to backward displacement by new clear lens fibers, the rosette is seen to be located deeper within the lens. If the injury occurred early in life, it may be expected that the opacity would be deeper than if the trauma were sustained later.


1252


BIOMICROSCOPY OF THE EYE


Thus in the former case the rosette may be found behind the adult nuclear zone (assuming that the adult nuclear zone becomes definitely delineated anywhere from the middle to the end of the second decade) (Fig. 437), or if the formation of the adult nuclear band is interfered with, it may be seen in a layer deeper than the surface of the adult nucleus in the fellow healthy eye. But if the injury occurs during or after this period, one should expect to find the opacity at the site of the adult nucleus or in the cortex in front of it. As evidence contributed to the thesis that the original location of a deep rosette (seen 3^ears after an injury) is subcapsular, Vogt suggested, the fact (i) that rosettes which develop immediately after injuries generall}^ are found to be subcapsular; (2) that in some cases a few residua of the opacity remain adherent to the capsule and behave like capsular cataracts; and (3) that the rosette form corresponds to the arrangement of the fibers in the subcapsular zone. From his observations and from those of others it appears that the late rosette (almost without exception) is a sign of contusion, which in most instances occurred during earl}'’ life. Frequently the injuiy itself ma}'’ have been forgotten b}'’ the patient.

If it were possible to account for all the variables, knowing the time of the injury, it might be possible in some of these cases to determine the growth rate of the lens in the period following the injury.'*'

In fresh cases the intensity of the opacity ma}'’ vary from a slight haze to a dense, white, shell-like la^'^er, the variation probably depending on the degree of trauma and the time of observation. In the first instance the lesion consists of a thin subcapsular layer of

Koby states; "In judging the depth of a rosette we must always bear in mind the possibilitj' of an arrest of development and similarly of an atrophy of the lens. When measuring the total thickness of an injured lens and comparing it with that of the lens of the other eye, we must naturally take care that all conditions of measurements are the same.” However, Vogt has shown that in cases where the injuries occurred early, i. e., in the first or second decade, the lucid layer (between the capsule and the rosette) was as much as one-sixth to one-seventh of the total lens thickness. In injuries sustained during the middle of the third decade, this distance w’as considerably less. Bellows, citing Nordmann, states: "that given a fresh case of traumatic rosette cataract, its future position may be predicted. Thus at the end of one and one-half years it will be deeper than the zone of discontinuity (line of disjunction [M.L.B.]) and in three or four years the opacity will lie in the region of the adult nucleus. He (Nordmann) points out that in younger individuals the apparent inward migration of the opacity is more rapid than in older persons.”


12J3


INJURIES TO THE LENS

fine droplets, lying between the radiating lens fibers. Reflection of light from these droplets results in a grayish opacity the periphery of which has a feathery appearance. The design of the fibers (feathery parallel lines) is thus seen better toward the periphery than adjacent to the usually darker appearing sutures. Vogt made an important differentiation between the appearance of the recent rosette and that of the late rosette. In the latter the suture ends mark the beginning of the dark incisures between the opaque "petals” of the rosette, so that the expansions or rays of the rosette reach much farther peripherally than the ends of the sutures (Plate LXXV, figs. 2, 3 ) . In the former (especially in recent posterior subcapsular rosettes) the rays follow the direction of the sutures, and the areas between the sutures remain clear to form the incisures.

The rosette shape of the opacity results from the suture design "which the opacity renders clearly conspicuous.” A "fresh” rosette or opacity, when it is of minimal severity (reminiscent of simple edema) has been known to clear entirely within days or weeks and leave no trace. This is especially true of certain of the posterior rosettes seen after perforating injuries (page 1267). As a rule traumatic rosettes are stationary in so far as their size and density is concerned and if not too opaque (which is commonly the case), they may not cause progressive loss of vision. But as both Davidson and Vogt have pointed out, their presence may later provoke early development of senile opacities. However, in more severe injuries irreversible reactions occur, and a permanent rosette figure may result. These likewise may vary from white opaque figures with feathery ends to those consisting of a solid, thin porcelain-like layer without any apparent internal fiber design.

Although both anterior and posterior rosettes have been described in cases of recent contusion, it appears from the cases described in the literature that the anterior one predominates. However, in my opinion, in cases of perforating injury of the lens the posterior rosette is more apt to occur. Not infrequently, when both anterior and posterior forms are present, or even in the absence of the latter, extensions lying in the same plane may peripherally outline the


BIOMICROSCOPY OF THE EYE

!’!ius in the former case the rosette may be found behind the adult t'.uwicnr zone (assuming that the adult nuclear zone becomes defiii,[v]\ delineated anywhere from the middle to the end of the second dec.ule) (Fig. 437), or if the formation of the adult nuclear band IS interfered with, it may be seen in a layer deeper than the surface ui the adult nucleus in the fellow healthy eye. But if the injury occur'; during or after this period, one should expect to find the opacity at the site of the adult nucleus or in the cortex in front of It. As evidence contributed to the thesis that the original location

â– if a deep rosette (seen years after an injury) is subcapsular, Vogt suggested, the fact (i) that rosettes which develop immediately

â– ficr injuries generally are found to be subcapsular; (2) that in M me cases a few residua of the opacity remain adherent to the cap-i.'ie and behave like capsular cataracts; and (3) that the rosette fi rm corresponds to the arrangement of the fibers in the subcapsular o te. From his observations and from those of others it appears that

â– . late rosette (almost without exception) is a sign of contusion, V inch in most instances occurred during early life. Frequently the . ijury itself may have been forgotten by the patient.

F It were possible to account for all the variables, knowing the lime of the injury, it might be possible in some of these cases to determine the grov.'^th rate of the lens in the period following the injury,'’

In Iresh cases the intensity of the opacity may vary from a slight ha'/.e to a dense, white, shell-like layer, the variation probably depending on the degree of trauma and the time of observation. In the first Instance the lesion consists of a thin subcapsular layer of

KiiSv st.ilL's: In iiiiimni: tiic depth of a rosette we must always bear in mind the

• Ilf an arrest of development and similarly of an atrophy of the lens. When measur in.; til-.- tot.d thicknc-'S of an injured lens and comparing it with that of the lens of the other

1', \i.(. mii,t n.itur.illy t.ike c.ire that all conditions of measurements are the same.” However, N < er h’.' tlut in c.Kts where the injuries occurred early, i. e., in the first or second

, th', iiitiJ i.rytr (hc.twten the capsule and the rosette) was as much as one-sixth to

“tal lens thickness, in injuries sustained during the middle of the third s', rao disi.aie'e- was con'idcr.ihly less. Bellows, citing Nordmann, states: "that given . 'rs'h e-'se <•: tr.unn.uic rosette cataract, its future position may be predicted. Thus at the ecu', it one- .'.nd o:re-h.df years it will be deeper than the zone of discontinuity' (line of -fi'-u; .:i. ". t.^(.I,.By) and in three or four years the opacity will lie in the region of the nu,i-.us He {N’or.im.tnn) points out that in younger individuals the apparent inward -n ■: the I'p.'city is more rapid than in older persons.”


1253


INJURIES TO THE LENS

fine droplets, lying between the radiating lens fibers. Reflection of light from these droplets results in a grayish opacity the periphery of which has a feathery appearance. The design of the fibers (feathery parallel lines) is thus seen better toward the periphery than adjacent to the usually darker appearing sutures. Vogt made an important differentiation between the appearance of the recent rosette and that of the late rosette. In the latter the suture ends mark the beginning of the dark incisures between the opaque "petals” of the rosette, so that the expansions or rays of the rosette reach much farther peripherally than the ends of the sutures (Plate LXXV, figs. 2, 3). In the former (especially in recent posterior subcapsular rosettes) the rays follow the direction of the sutures, and the areas between the sutures remain clear to form the incisures.

The rosette shape of the opacity results from the suture design "which the opacity renders clearly conspicuous.” A "fresh” rosette or opacity, when it is of minimal severity (reminiscent of simple edema) has been known to clear entirely within days or weeks and leave no trace. This is especially true of certain of the posterior rosettes seen after perforating injuries (page 1267). As a rule traumatic rosettes are stationary in so far as their size and density is concerned and if not too opaque (which is commonly the case) , they may not cause progressive loss of vision. But as both Davidson and Vogt have pointed out, their presence may later provoke early development of senile opacities. However, in more severe injuries irreversible reactions occur, and a permanent rosette figure may result. These likewise may vary from white opaque figures with feathery ends to those consisting of a solid, thin porcelain-like layer without any apparent internal fiber design.

Although both anterior and posterior rosettes have been described in cases of recent contusion, it appears from the cases described in the literature that the anterior one predominates. However, in my opinion, in cases of perforating injury of the lens the posterior rosette is more apt to occur. Not infrequently, when both anterior and posterior forms are present, or even in the absence of the latter, extensions tying in the same plane may peripherally outline the


1254


BIOMICROSCOPY OF THE EYE


"equator” of the involved layer. In this way they may connect the anterior rosette with a posterior one or if the latter is not present, it may just extend backward for a short distance into a corresponding layer of the posterior parts of the lens. In several cases reported by Vogt and by Haldiman,'*®*’ there was a second opacity located peripherally to, and a little in front of the main rosette. Vogt does not consider the presence of the second opacity a rarity in contusion cataract. This second, anterior opacity frequently extends to the equator where it may meet an opaque line running concentrically with the equator. Outside this, smaller discrete, dustlike opacities may occur.'’*

The rosette figure is not complete in every case since at times only one or two "petals” may be visible, and these probably at the site where the greatest part of the force was transmitted. After especially severe trauma thin, dense shell-like opacities without rosette formation may form and like delayed or late rosettes may be found displaced deeper into the lens after the passage of years. In these cases it is not unusual to find a decrease in total sagittal thickness of the lens.

From the standpoint of differential diagnosis there should be little difficulty in diagnosing the fresh traumatic rosette opacity. With the history of a recent contusion, the finding of a subcapsular rosette figure together with other obvious signs of trauma, i.e., ruptures of the iris sphincter or iris tissue, hyphemia or its residue of pigment, one-sided mydriasis, etc., substantiate the diagnosis. However, delayed rosette opacity may have to be differentiated from complicated cataract, saucer cataract (cupuliform) , and a type of senile cortical

The exact time of formation of such extrarosette opacities is not known but Vogt suggests three possibilities, first that they arise simultaneously but independently, the anterior one subcapsularly and the deeper one in the first zone of discontinuity and that later both were pushed back by new fibers. Second, the deeper of the two located subcapsularly could develop first and be pushed deeper before the more anterior one developed, and finally, the original opacity could be separated into two layers by the ingrowth of new fibers. According to Haldiman, traumatic rosette cataract was observed in several cases immediately following contusion. Two layers of opacity were seen simultaneously: the first subcapsular was gray and the second located behind it in the region of the anterior disjunction line or at the level of the adult nucleus band was more yellowish. When sufficiently developed both showed a leaflike structure. In the course of a few months both were displaced backward, the deeper opacity became more distinct, while the superficial one became partially resorbed.


1255


INJURIES TO THE LENS

cataract the radiating structure of which (Handmann) may resemble a rosette. Posterior complicated cataract (secondary to intraocular disease) (page 1169) is characterized by a polychromatic iridescence in the early stages and later by the "breadcrumb-like” appearance of the opacities. The opacities are not limited to a single zone of discontinuity but tend to progress from the posterior subcapsular region anteriorly toward the posterior adult nucleus as well as in a radiating manner. Posterior saucer cataract (composed of a vacuolated material) is limited to the posterior subcapsular zone and usually has a yellowish reflex. Its frontal boundary always is sharply demarcated from the lens substance in front of it. In neither of the latter are the feathery fiber design seen nor are the opacities pushed toward the center of the lens by clear lens fibers. In certain cases, especially in their early stages, anterior saucer and anterior complicated cataract may morphologically in a gross way resemble a recent traumatic rosette. The former are directly subcapsular and may have a thin radiating character but they do not have the characteristic fiber design as described above. Unlike the late traumatic rosette they are not displaced deeper with time. On many occasions the author has seen thin radiating senile cortical opacities (Handmann) which by diffuse illumination might be mistaken for a rosette. In these cases the optic section will reveal that the opacities result from typical senile and presenile lens alterations (water slits and laminary separation, etc.) and that they differ from the typical "petal” shaped opacities of the traumatic rosette, the ends of which, although feathered, usually have a regular convex arcuate border.

TRAUMATIC LAMELLAR (ZONULAR) CATARACT

The uniocular formation of typical lamellar or zonular cataract (page 1071) following contusion has been reported by several authors. A review of the literature pertaining to this subject was made by Walter (1917)®^^ and by Law (1932).°^® The outstanding points noted by Law were that (i) a great majority occurred before 12 years of age (in 22 cases only 2 occurred after the age of 20 years) ; (2) in a high percentage the injury sustained was of the nonpene


1256


BIOMICROSCOPY OF THE EYE


trating type (contusion) (Plate LXXV, fig. 6); and (3) of the latter as many as half the patients had subluxated or luxated lens. Zonular opacity of the lens develops from other than hereditary causes, e.g., tetany cataract. Evidently whatever the cause, e.g., toxins or increased permeability of the capsule (in injuries - damage to the epithelium or minute ruptures) , the time and duration of the insult is all important. In the young, it is conceivable that when the time of action of the disturbing factor is limited to a short period, subsequent new lens fibers could be laid down in a normal way so that in the end a circumscribed perinuclear layer of opacity separated from the capsule by a lucid layer would be found."' In such cases, if the injury occurred early (before the adult nucleus is definitely dtlineated) the opacity would surround the outer embryonal or fetal nucleus but if it occurred somewhat later (after adolescence) the adult nucleus itself might be affected. As already noted, in hereditary zonular cataract or in those resulting from exogenous causes (tetany) the opacity may be complete or partial. Riders may or may not be present. I recently observed a case (a perforating injury with marked hyphemia in a 22-year-old man) in which three weeks later, in the operative coloboma, a double layer of typical linear opacities were seen outlining the equator of the adult nucleus. Slight iridonesis suggested that some degree of subluxation was present. Dilatation of the pupil of the fellow healthy eye revealed no coronary or other opacities. The opacities began in an area corresponding to the peripheral one-third of the anterior surface of the adult nucleus and continued around the equator to about the same area on the surface of the posterior adult nucleus - an example of a partial or incomplete zonular opacity. These opacities had a somewhat yellowish

According to Law: ' Such an event could result from a temporary alteration in capsular permeability caused by a severance of the physiological connection between the capsule and the lens, with a consequent alteration in its osmotic properties, or - alternatively and rarely - by a perforating capsular injury' which subsequently healed. In each of these cases, degenerative ciianges wimld occur in the periphery' of the lens as then constituted, if an approximation to natur.il conditions was restored without delay', the nutrition of the central lens fibers would not be disturbed and the fibers laid down subsequently would again be transparent. According to the severity or duration of the alteration in phy'sical properties of the capsule so would the transparency of the central lens or the younger peripheral fibers be affected to a greater or lesser degree.”


1257


INJURIES TO THE LENS

tinge. It is of interest that in many of the cases of traumatic zonular cataract varying degrees of subiuxation and luxation of the lens have been noted. The frequency with which opacities appear in anteriorly displaced lenses has already been touched upon. The tearing of the zonular attachments in itself may play a role. As Vogt pointed out, atropine mydriasis should be used with caution after ocular injury (see footnote, page 1259) because with relaxation of the zonule, the capsular tension increases and small wounds in it may consequently be caused to gape, thus not only interfering with healing but also permitting greater access of aqueous into the lens substance.

PRESENILE AND SENILE-LIKE LENS OPACITIES INDUCED BY CONTUSION

That lens opacities, morphologicall)^ similar to the common varieties ordinarily known as presenile or senile lens alterations, may be initiated or intensified by contusion has been attested to by the findings of many observers. Among these changes are coronary and cerulean (page 1071) opacities, zonular cataract, punctate cortical opacities, water slits and spokes, and nuclear cataract (Fig. 464). Vogt reported on a case in which an explosion twelve years before affected the left eye. The cornea was not injured. In addition to several oval opacities axially he found typical coronary and cerulean opacities in the periphery of the anterior and posterior cortex. These consisted of typical clubs and disks. More axially there were blue and brown disks and larger lancet-like streaks (frequently seen in cerulean cataract) . The lens sagittally was thinner than that of the unaffected right eye. However, when the pupil of the right eye was widely dilated, it was possible to make out faint traces of coronary opacities. He concluded that in this case the severe trauma intensified the antecedent cataracta coronaria and cerulea. He also cites other cases where pre-existing coronary opacities increased in number and size following trauma. In this connection, Vogt reminds us of other senile conditions that may also appear when provoked by exogenous causes, e.g., arcus senilis and corneal lines (HudsonStahli) .


1258


BIOMICROSCOPY OF THE EYE


I have several times noted the presence of punctate and dustlike opacities, especially in the peripheral cortex, following contusion. These are similar to those described as senile punctate opacities (page 1123). Such opacities were particularly marked in a case in which the lens was subluxated upward, permitting a better view of the lower equatorial regions of the lens. In many of these cases the fact that the punctate spots were either absent or at best sparse, in the unaffected eye, indicated their connection to the injury.

Traumatic Cataract Associated with Rupture OF THE Lens Capsule

Rupture of the lens capsule in either its anterior or posterior parts (Perforatio Lentis Traumatica) invariably results in cataract formation. Although tearing of the capsule may follow contusion even in the absence of any demonstrable rupture of the outer tunics, usually it is associated with perforating or penetrating lesions. The biomicroscope is of inestimable value in detecting faint, perforating corneal wounds (especially those at the limbus), small holes in the iris, scleral or conjunctival hemorrhages, and conjunctivo-scleral scars (especially pigmented) - all indicative of perforation. These are frequently overlooked by cruder methods of examination. Confirmation of the perforating nature of the injury may be obtained by the ophthalmoscopic presence of chorioretinal scars in the fundus behind the site of the above mentioned lesions, i.e., along the track of the penetrating missile. But it must be admitted that in certain instances very small penetrating foreign bodies may leave no external trace of their passage into the eyeball. Hence, it is axiomatic that when one is confronted by an inexplicable unilateral lens opacity, radiographic examination should be made for the presence or absence of a foreign body.

The opacification of the lens following rupture of the capsule probably is due to direct injury of the fibers themselves and the action of the aqueous upon them. Hence it is conceivable that with rapid sealing off or closure of a capsular wound after a penetrating injury, a localized stationary lens opacity could result. Such a con


1259


INJURIES TO THE LENS

dition is seen frequently following penetrating injuries (by sharp instruments or foreign bodies) , especially when they have entered the peripheral parts of the lens. On the other hand, a slight rupture of the capsule (especially in the axial regions) may be followed within hours by rapid intumescence, leading to total cataract.

With large capsule rents the lens substance rapidly swells to a high degree so that obliquely placed fibers are often seen protruding either into the anterior chamber or into the vitreous. In the young, depending on the circumstances, partial to complete absorption of lens substance follows so that in the end conditions varying from secondar}'^ cataract to aphakia may occur (see Fig 453). In older individuals, the inabsorbable sclerosed nucleus when exposed provokes a foreign body reaction with dire results. Even in the absence of infection disintegrating lens matter may act as an allergen, inducing complications (uveitis [phaco-anaphylactica] and secondary glaucoma). As in severe contusions, traumatic perforation of the lens capsule may also result occasionally in the appearance of either partial or complete anterior or posterior rosette opacities, the posterior probably being more common (Figs. 441 A, B; 442; 443). The rosette may be found at the first examination after the injury

In his remarks about the behavior of capsular wounds, Vogt stated that it is well known that circumscribed wounds of the lens behave differently from case to case and that their course is unpredictable. This also applies to "needling” operations. In one instance a smallsized opening may lead to a total cataract and in another it may close quickly. Likewise in lenses in which the capsular opening is large and even when perforation of the lens substance has occurred, a small localized opacity may result. This also applies to luxated lenses, especially those where the displacement occurs spontaneously. Surgeons know how difficult it is to cause these to mature by needling. In several cases, even after two needlings Vogt succeeded only in obtaining a limited opacity at the site of the capsular tear. Perhaps the surrounding viterous played a protective role in some of these cases but it was difficult to obtain opacrfication of the lens even when there was no vitreous in the neighborhood of the wound. He concluded that the cause of this special behavior in luxated lenses is to be found in the fact that owing to the lack of zonular and capsular tension, there is less tendency for capsular wounds to gape. This also holds true for animals (rabbits and lower vertebrates) in whom, as was previously pointed out by Knapp, it is difficult to cause opacification of the lens by needling. Owing to the lower power of accommodation in these animals their capsules are less taut and stretched than is the case in humans. Reasoning from these observations, Vogt cautioned that the use of atropine (except in the presence of infectious inflammation) immedrately after capsular ruptures should be avoided since with paralysis of accommodation there is an increase in stretching or tension of the lens capsule. Hence, when possible, relaxation of the zonule with miotrcs may be useful. For the same reason, when the capsule wound is located behind the iris, it might be dangerous to atropinize the eye at an early stage when the iris may furnish a useful and protective exudate. Iris traction (by atropine) conceivably might tear open the freshly adherent capsular wound.


1260


BIOMICROSCOPY OF THE EYE


and may either retrogress (edema ?) or, when irreversible, damage to the lens fibers has occurred, may become more opaque and consequently stationary. As a matter of fact, the lens opacities following the penetration of foreign bodies, except those marked by a complicating siderosis, do not differ essentially from those described as contusion opacities, with the possible exception of the senile type of contusion opacities (page 1257) . The partial lamellar type, in which the single-layered opacity extends around and accents the equator of the layer in which it lies (like zonular opacities) , is not uncommon (Plate LXXI, fig. 6 ) . This suggests that the penetrating foreign body may produce the effect of contusion.

At this place it is appropriate to mention the danger of inducing traumatic cataract (rupture of the capsule) at the time of operative intervention for glaucoma. Kirby pointed out that Wheeler warned about this accident (improper keratome incision; attempting to grasp the iris too close to its pupillary border, etc.) . In the presence of high intra-ocular pressure, it is possible that owing to the sudden decompression following upon opening of the anterior chamber, that rupture of the posterior capsule may occur.

Davidson states: "(i) A survey of 6 i lens lesions, primarily opacities, observed in cases of eye perforation by intra-ocular foreign bodies and in eye rupture without retention of foreign body, indicates that the majority are the result of lens contusion and morphologically belong to the type of contusion-lens opacities previously studied. Posterior feathery star-shaped opacities are evidently rare.

"(2) Capsule perforation, lens penetration, or its double perforation occur in less than a third of the cases that do not lead to immediate cataract.

" ( 3 ) The retrospective diagnosis of the eye perforation or rupture origin of a lens opacity is sometimes made difficult because of the eventual blurring of the perforation or rupture character of a corneal scar after many years and particularly because of the difficulty in diagnosing an older partial limbus and scleral perforation or rupture.

" (4) The rate of recession into the depth of the lens of originally


1261


INJURIES TO THE LENS

subcapsular opacities is found to vary . . . just as in the study of pure contusion lens opacities. The factors affecting the rate seem to be: capsule lesions, which tend to retard it; varying depth of lens penetration, which would tend to accelerate it; hypertension [increased intra-ocular pressure, M. L. B.] and siderosis, which tend to retard it; and hypotension [reduced intra-ocular pressure, M. L. B.], which favors it.

"(5) As for the evolution of the lens lesions in this mild variety of cases, the end results are satisfactory in the majority of cases, but prognosis should be more guarded in the individual after he is 30 years old. Deterioration should be watched for in the fifth decade when apparently most deteriorations occur.”

From the standpoint of the biomicroscopic appearance the following changes in perforating injuries of the lens will be considered:"' (i) visible capsular wounds and scars; (2) posterior subcapsular rosette cataract and its resorption (Fuchs, Avizons, Vogt); (3) localized (stationary) opacities (cataracta traumatica circumscripta) ; (4) intumescent (total) traumatic cataract; (5) traumatic folds of the capsule and (6) changes in sagittal lens thickness (post-traumatic atrophy of the lens - Vogt) .

VISIBLE CAPSULAR WOUNDS AND SCARS

The biomicroscope permits the inspection of the anterior and posterior parts of the lens capsule over an area limited only by the size of the pupillary opening. The equatorial areas ordinarily present difficulties in visualization, except in the presence of an iris coloboma, ectopia lends, or following iridodialysis. But even in these cases damage to the capsule at the equator is not easily demonstrable. In many instances sharp delineation of the capsule stripe by means of the optic section may not be possible immediately after the injury owing to the corneal changes (edema) , and to increased turbidity of the aqueous either from exudate or blood cells. "When the capsule stripe can be clearly seen, any break in its continuity will be appar ^ It should be remembered that like traumatic injuries in general, no two are morphologically alike and hence one can only describe them generally.


1262


BIOMICROSCOPY OF THE EYE


ent as the beam is passed over its surface. Capsular wounds tend to gape somewhat and the edges tend to roll outward. Individual opaque fibers or masses of opaque lens matter often may be observed to protrude mushroom-like into the anterior chamber. After a time, within the unabsorbed protruding opaque mass, fine chalky crumblike granules and dots form. When these are seen in a capsular wound, it is an indication that the lens masses are no longer fresh and that the condition has existed for some time.

Immediately following the injury, the edges of the wound become more opaque, often resulting in the formation of an oval ring or slit of varying size. Protrusion of opaque fibers through this opening is not seen in every case. A halo-like second ring, grayish and opaque, may be seen to surround the inner ring. There may or may not be any bulging of the lens within the ring. With high magnification it may be seen that the grayish halo (surrounding the capsular wound) which at times contains pigment granules has the character of an exudate, adherent to the capsule. Evidently a gap in the capsule may become covered over with a thin layer of fibrin. Vogt described such a case in which two years after injury by a perforating foreign body a spontaneous rupture occurred within a well-formed ring, so that at this late date opaque lens masses suddenly began to protrude into the anterior chamber. When a perforating object passes through the iris (leaving a hole) near the pupillary margin, an iridic adhesion to the capsular wound may occur because of exudation. This may serve to plug the capsular wound, thus limiting the extension of the cortical opacification.

It should be noted that following perforation of the lens by small foreign bodies, opacities of the anterior capsule may not always be found biomicroscopically. In his series of 62 cases, Davidson was able to demonstrate capsular injuries in only twelve cases. In six of these there was double lens perforation with a demonstrable tract in the lens. In one case the capsular lesion was seen at a distance from the end of the tract similar to the cases reported by Meesmann. Considering the fact that the direction of most perforating foreign bodies is oblique it may be that the lens often deflects them or else


43S. Tr^urn . MfT

"»reSiMo/S,j* '" ™ps„,e ,

"" M/to v„^"5®" /»


C^ftfr^Du a;


i263


1264


BIOMICROSCOPy OF THE EYE


their entrance is not demonstrable. In the case of the former the resulting opacities may be the expression of a contusion. Davidson noted that double lens perforation and anterior capsule perforation were conspicuously more frequent in the older age groups - a condition possibly accounted for by capsular friability.

With healing, a dense scarlike opacity may result, and characteristically the anterior line of disjunction is usually not distinguishable within it (Fig. 438). At the margin of the opacity the fiber design may be visible as radiating white lines (Fig. 439). The presence of pigment at the site of a capsular scar should always be looked upon with suspicion. The force exerted by the penetrating objects may cause the cornea to be momentaril)'^ pressed backward against the iris; this in turn strikes the lens so that pigment may become adherent to the capsule or forced into the lens at the site of the capsular wound. It is possible that when a penetrating object passes through the iris, some of its pigment may be carried along with it. In the neighborhood of capsular opacities it is not unusual in the zones of specular reflection (mirror region) to observe iridescence. This phenomenon is probabl)'^ due to interference effects.

As a consequence of the formation of a capsular scar, traction folds may result. They may radiate fanlike or may extend irregularly. Irregularities in the curvature of traction folds are frequent. In the latter case the narrow beam may show troughlike depressions. Within the center of old perforation scars of the anterior capsule, occasional!}’" a "blister-like” lens spherule ma}'^ appear. These resemble dark structureless giant subcapsular vacuoles but differ in the fact that they protrude from the opaque surroundings (Fig. 440 A, B) . Although they are dark in direct focal light, they appear to have a delicate whitish envelop and hence are unlike the so-called "Kugeln” or grapelike cysts (Elschnig, Hirschberg) usually associated with secondar}’" cataract or membranes. Because of the opaqueness of the surrounding scar it ma}’" be difficult to observe them by retroillumination. Such bodies may represent a cystic degeneration of the capsule or, as suggested b}’" Vogt, "an epithelial product.” They have not been seen on the posterior capsule.


In 1 -r Ti-^


nr


.-fT?


â– WA


\


\. 1%


%


.V


M * '


) 1


J1


.~tf


m


/


)' < fy^S r

' ’I .


^ \


9 \

J\.iy


^r^teaor , f '

places r ^^"'«psuie. ^ P I

f injury, r , • v,e^. 3, _ B ^

ere ^gre uppg^ "^ct^on

^at ^eresij^-, suh ^ ^ °I the 1^

â– tt" -"«? '* » « â€œc •"■“•“« 

"r-«:;" ”»» - L";

^nd ha, ri ^ ah • ^a^e .

^^turally Co, ^^tnaged ^ iia? ^

"" "' *• S?: ‘" ■cstr,"- -s;'” •“'•

iode.


A



a perforat view\ B.


ing injury. Site of perforation 'Jptic section.


1266


1267


INJURIES TO THE LENS

pendently of the actual passage of perforating objects through it. This may happen also in cases where the penetrating object does not reach the posterior capsule. As a result of compression from the force of the injury (as explained by Frankel) in the contusion syndrome there is an increase in the equatorial diameter of the lens. This may by itself rupture either the zonule, the posterior capsule (which owing to its thinness is more liable to rupture than the anterior capsule) , or both.

Localized posterior subcapsular crumblike opacities may be found which resemble posterior complicated cataract (page ii68) and may lie in front of scars of the posterior capsule. In adults, owing to increase of yellow tones in the posterior parts of the lens the crumblike opacities may have a yellowish color in contrast to the whitish aspect of the more anterior parts of the opacity. Following perforation of the posterior capsule, opaque lens masses may be forced backwards into the vitreous. These masses will oscillate within the vitreous with movements of the eyeball. As a rule, the exit wound of the posterior capsule tends to be larger than that of the entrance wound of the anterior capsule. This is to be expected because as the foreign body passes through the lens a larger area of displaced tissue is forced backward. As in the case of myelin droplets the light reflected back from the fundus may cause the edges of a posterior capsular wound to glow with a reddish color. Upon healing, the optic section frequently shows that the scar in the posterior capsule bulges concavely backward.

POSTERIOR SUBCAPSULAR ROSETTE CATARACT AND ITS RESORPTION

As mentioned previously in the section on contusion cataract, rosette-shaped opacities also may develop following perforating lens injuries (Figs. 441 A, B; 442 A; 443 ) . They usually occur in the cases in which the opening rent in the capsule has been small and in which owing to capsular closure, complete opacification of the lens (intumescence) does not obscure this delicate change. Consequently most of the cases that show such capsular closures are instances of damage caused by the penetration of pointed instruments (needles)


1269


INJURIES TO THE LENS

or small foreign bodies. Within a few hours or during the first few days after the injury biomicroscopic examination, especially in the posterior parts of the lens, may reveal the presence of a rosette


Fig. 443. Perforating injury. Posterior rosette.


opacity. It is located just in front of the posterior capsule (axially) , and its structure sharply outlines the suture and fiber design. The rosette tends to lie more or less in one plane and is relatively of little thickness. The sutures appear dark and extending from them are feathery grayish to yellowish lines (depending on the color of the posterior cortex) . Each division or "petal” of the rosette can be compared to a feather in which the central spine or suture is dark, thus differing somewhat from the contusion rosette where the end of the suture marks the beginning of the incisura. In direct focal illumination the surface of the rosette may glitter, somewhat resembling the sheen from a thin layer of crystallized boric acid (Vogt). Transillumination by means of the ophthalmoscope reveals a vacuolated structure, which gives the impression of a figure formed by a layer of subcapsular fluid or exudate outlining this fiber design (Fig. 443). According to Vogt, the sutures are a locus minoris resistentiae, permitting the entrance of fluid that reaches the fibers. This observation may explain the physiologic manner


1270


BIOMICROSCOPY OF THE EYE


in which the nourishing fluids get to the fibers. The suture planes extend through the whole depth of the lens substance and hence represent the only way in which fluids could gain access to individual fibers. The fact that this type of opacity can resorb within a short period after its appearance (a fact first noted by Fuchs) would indicate that the fibers in themselves are not irreversibly damaged. Avizonis reported a case in which a posterior contusion rosette cleared entirely within a month. In one of Vogt’s cases the original size of the rosette was 45 mm. in diameter. Within a month it shrank to 0.75 mm. in diameter so that with the ophthalmoscope only a few faint dots remained visible. The vision during this time improved from 6/18 to 6/8. In these cases when a penetrating object passes through the lens, an opaque tract extending from a wound in the anterior capsule to a posterior rosette figure will be seen (Fig. 443 ) and if the posterior capsule is injured, there may be an opacit}'’ in it either in connection with the rosette or just behind it. Flowever, a posterior rosette figure can form in the axial region even if the injury does not extend through the entire lens thickness and also when the direction of the entrance wound is not axial, e.g., at the equator. According to Wagenmann,®®^ even when the injury is localized to the anterior part of the lens fluid very quickly may make its way posteriorly by following the equatorial curve of the involved plane so that an opacity remote from the injured site may occur. This again would emphasize the concentric lamellar structure of the lens - an architecture seen physiologically in the behavior of the zones of discontinuity.

LOCALIZED TRAUMATIC STATIONARY OPACITIES

In addition to the rosette opacity just described which has a predilection for a special locality in the lens and the form of which follows the morphologic structure of the lens, perforating lens injuries may cause permanent localized and stationarj’^ cataracts (Cataracta Traumatica Conscripta). These consist of irregular opacities, varying in size and shape from small dots or lines to large cloudlikc masses, limited to the injured area (Fig. 442 B). In the


1271


INJURIES TO THE LENS

periphery, flattened thin opacities having a pyramidal (cuneiform) or semilunar shape are not uncommon. Many extend posteriorly by passing around the equatorial region of the involved plane similar to lamellar opacities.

The track of a penetrating injury may be marked by a linear opacity which consists of streaky lines or dots or may have a solid spear-like character. With rapid closure of the capsule this may remain as permanent unchanging evidence of a past perforating wound. When peripherally located it may be necessary to dilate the pupil to see such opacities. After the passage of a foreign body through the equatorial region of the lens it is not unusual to see more or less localized irregular masses of opacity limited to this area. They are cloudlike and not sharply delimited, show little tendency to progression and may not markedly impair vision.

Several years ago I saw the case of a 27-year-old man in whom a tract of scar was seen traversing the corneal thickness of the left eye at about 5 o’clock near the limbus. Just behind this there was a small hole in the iris, which only became apparent by retro- and transscleral illumination. It was only upon maximal dilatation of the pupil that a large fluffy opaque cataract, involving the entire thickness of the equatorial region, could be seen (Plate LXXI, fig. j).. The patient came to the clinic for a refraction unaware of any previous trouble and it was only on questioning his parents that a history of a long-forgotten injury in early childhood was obtained. At the age of three, this eye had been perforated by a hat pin while the boy was playing with his older sister. I have seen several similar lens opacities following perforating foreign bodies that passed through the periphery of the lens. These opacities may show no vacuoles, water slits or fiber design, and usually they are not limited to any one zone of discontinuity. Similar irregular opacities in the equatorial regions may be seen in cortical senile cataract, but with careful inspection particularly at the axial borders, it will be noticed that they are the extension of either a radial spoke or cuneiform opacity.


1272


BIOMICROSCOPY OF THE EYE


INTUMESCENT AND TOTAL TRAUMATIC CATARACT

As a rule, larger capsular rents tend to provoke total cataract because of the greater separation of their edges. However, as previously


Fig. 444. Intumescent cataract. The fibers are separated and twisted.


pointed out there is no definite relationship between the size of the capsular opening and the amount of lenticular opacification which ensues. Openings of the capsule (anterior or posterior) may lead to rapid intumescence and complete opacification. The end result of this process will vary in each individual case, depending on whether or not the capsule rent closes, on the age of the patient, and on the presence of other intra-ocular complications. In the young, partial or complete absorption of the capsular contents may occur, resulting in aphakia. After the third decade, the presence of a ruptured capsule and intumescent lens is more serious, and because of the complications (iritis, glaucoma or even sympathetic ophthalmia) , removal of the cataractous lens may become imperative.

Intumescence is manifested biomicroscopically by the separation of the opaque fiber bundles by dark slits or gaps. At times fiber bridges (comparable to twisted and separated wool fibers) cross the


1273


INJURIES TO THE LENS

gaps obliquely (Fig. 444) . The similarity of this picture to that seen in senile intumescent cortical cataract has been pointed out, and one gets the impression that water imbibition has forcibly torn the fibers apart. In other cases a layer of subcapsular vacuoles may be seen in front of opaque cortical masses. Protrusion of swollen lens fibers out of the capsule and into the anterior chamber not only tends to keep the capsule rent open but also permits the continued lytic action of the aqueous on the fibers.

With closure of the capsular opening (by exudate or adherent iris) the process of intumescence may be localized to a minimal extension of the cortical opacification. In this case the lesion may be limited to some short fine superficial stripes radiating from the capsular scar, showing no further signs of progression. Cases have been reported in which spontaneous reopening of a sealed-off capsular rent occurred years after the original trauma, with consequent extrusion of lens matter into the anterior chamber.

In injuries to the posterior capsule the tendency to intumescence of the cortex is not as rapid or widespread as in the anterior cortex. It may be that the presence of the vitreous in juxtaposition to the posterior capsule may mitigate against the entrance of fluid into the posterior cortex, thus inhibiting rapid opacification. Consequently the resulting lesion will tend to be more localized. This is emphasized by the frequent presence of localized capsular scars and opacities of the posterior cortex.

However, in cases of double perforation by foreign bodies, rupture of the posterior capsule (the exit opening may be larger than that in the anterior capsule) may be followed by the protrusion of the opaque lens masses into the anterior vitreous. Some of these opaque fibers may become detached and may float with the movements of the vitreous, and later, if visibility through the lens permits, may resemble the bodies of asteroid hyalitis.

TRAUMATIC FOLDS OF THE CAPSULE

Folds of both the anterior and posterior lens capsule may follow perforating lens injuries, especially in cases in which traction scars


1274


BIOMICROSCOPY OF THE EYE


develop in the capsule. As a rule the folds tend to radiate from the scar. Ruptures of the capsule may also cause folding by Idnking, even in the absence of contracting scars. Capsular folds show characteristic double reflexes and are usually pointed at their ends, having a lanceolate appearance (Fig. 439). Those of the posterior capsule can be verified by use of the optic section. Here adherent pigment particles and opaque vitreous strands may be observed. Bright red blood clots, adherent to the folded posterior capsule, may also be seen for months after an injury. Folds of the anterior capsule may occur even without capsular traction scars in cases of contusion cataract which tend to become hypermature (Plate LXXI, figs. I, 2). After perforating injuries, adhesion of a torn capsule to either the iris or cornea may cause capsular folds in the neighborhood of the adhesion.

CHANGES IN SAGITTAL LENS THICKNESS

In demonstrating changes in the sagittal dimension of the lens, especially reduction in volume that ma}'’ occur after severe trauma, use of the optic section is essential. As already indicated, such reductions in volume may also occur after severe contusions in which no capsular opening can be found (posttraumatic atrophy of the lens) . Following a contusion, Vogt found that the ratio of the sagittal thickness of the injured lens to that of the uninjured lens in the fellow e)’'e was 2:3. In the cortex behind the somewhat flattened capsular stripe which contained spotlike opacities (Fig. 443)3 there were two well-marked zones of discontinuity. The deeper one fused peripherally with the adult nuclear stripe, which was flattened and ver)’- relucent. The peripheral convergence of the zone of discontinuity was probably a result of the disturbance that caused a reduction in lens volume. Contrary to the general occurrence in cases in which the loss of sagittal thickness follows perforation of the lens capsule with consequent shrinking, folding of the capsule was not seen. The cause of the reduction in volume of the lens after the contusion could be explained by resorption of the opaque or damaged fiibers and also by a disturbance of growth resulting


1275


INJURIES TO THE LENS

from epithelial damage. That thinning of the sagittal lens thickness should occur following perforating injuries is thus to be expected. Usually the thinning is. more likely to be found in the neighbor


Fig. 445. Changes in sagittal lens thickness. (After Vogt.)


hood of the perforation - the place where opacification and destruction of lens substance is greatest. In this region, besides opacification, large subcapsular water-slits may be found. In these cases folds of the capsule, similar to those described in hypermature cataract, are common. Damage to the lens epithelium, especially if the wound is equatorial, would prevent new lens fibers from growing in or at least would impede their full growth. Hence if apposition of lucid young fibers does occur, it will only appear as a thin clear layer and will not add considerably to the total lens thickness.

In contradistinction to thinning of the sagittal thickness of the lens after contusions and perforating injuries, an increase in sagittal lens thickness may be noted in cases of chronic glaucoma. In these cases the sagittal thickness of the nucleus (which is more relucent than normal) seems wider at the expense of the cortex.

Lens Changes Following Penetrating Foreign Bodies

The penetration of foreign bodies into the eyeball constitutes a large percentage of industrial ocular injuries. The lens may be directly injured, or changes in it such as complicated cataract may be set up secondarily in consequence of effects of the injury (e.g., inflammation or infection) or by the retention of certain metallic


Fig. 446. Foreign body in the lens located near the anterior Y. The opacity of the anterior suture and the punctate opacities are congenital, since they were seen also in the unaffected right eye. (After Duverger and Velter.)



Fig. 447. Foreign body in lens. Note blister-like degeneration of capsular epithelium at the entrance wound in the capsule. Total cataract. (After Vogt.)


INJURIES TO THE LENS 1277

foreign bodies within the eye (e.g., iron and copper) . In the case of the latter, owing to physicochemical causes, metallic impregnations occur within the lens as well as in other parts of the eye (the epithelial tissues being especially vulnerable). With the exception of iron and copper, it is well known that - excluding the direct local injury to the lens fibers and the effect of open capsular rents (lytic action of the aqueous) - the lens tolerates most foreign substances very well.* The effects of the penetration of such substances differs in no way from those described under penetrating injuries of the lens. In a few cases inert foreign bodies in the lens, even when they have been present for a long time, have been known to produce only a localized opacity without any complicating reaction (Fig. 446). However, in most cases total cataract eventually occurs (Fig. 447)- Frequently even in the absence of introduced infection or toxic effects from retained iron or copper the presence of an intra-ocular foreign body results in a plastic iridocyclitis with or without increases of intra-ocular pressure. Such a condition may excite sympathetic ophthalmia. The importance of biomicroscopic examination in suspected cases of intra-ocular foreign body cannot be too strongly emphasized. It may be the only way by which it is possible to detect delicate wound tracts in the cornea or neighboring sclera, iris, and lens. Discoloration of the cornea, iris, the anterior subcapsular regions of the lens, and the vitreous in siderosis, chalcosis, or hydragyrosis may only be revealed through the medium of biomicroscopy. Even in the absence of any discernible wound tract, the appearance of an otherwise inexplicable monocular cataract always warrants radiographic investigation. Foreign bodies entering the lens through the pupil are less liable to cause an immediate iritis or hyphemia than those in which perforation of the iris has occurred.

In World War II as a consequence of aerial flak, secondary fragments of plastic material from the windshields or turret blisters were not infrequently seen in wounded personnel. With the biomicroscope small slivers of slightly refractile homogeneous plastic surrounded by a faint area of opaque lens matter were seen embedded intralenticularly. These in themselves appeared to be well tolerated within the lens. Also as a result of plastic mine explosions, the green plastic material employed in the construction of the German mine was discovered embedded in the lens as well as elsewhere in the eye.


PLATE LXXVI


Fig. I. Siderosis lentis. Diffuse illumination. Total cataract. Note the radial disposition of the deposits.

Fig. 2. Same case as shown in Figure i. High power. Diffuse illumination. Note the groups of small dotlike deposits and also larger areas of stain. The iris is discolored.

Fig. 3. Siderosis lentis. Posterior complicated cataract with polychromatic iridescence. Pigmentation of the vitreus.

Fig. 4. Sunflower cataract in chalcosis lentis.

Fig. 5. Subcapsular location of the deposits in chalcosis lentis.

Fig. 6 . Posterior complicated cataract in retinitis pigmentosa associated with unusual pigment deposits on the posterior lens capsule.


1278


INJURIES TO THE LENS


1281


SIDEROSIS OF THE LENS (SIDEROSIS LENTIS)

A deposition of "rust” in the lens occurs either when a ferrous particle has perforated or lies within the lens or as part of a general ocular siderosis even in cases where the lens itself was not injured primarily. In the former case one may find localized areas of discoloration in the neighborhood of the particle or splinter, while in the latter, when the metal lies outside the lens, a more characteristic and regular disposition occurs. However, exceptions frequently are seen. As is the case with other perforating foreign bodies of the lens, probably dependent on capsular closure, a localized opacity with varying degrees of neighboring discoloration may occur, or with rapid intumescence a total cataract may follow, this also may show varying degrees of rust deposition.

The more characteristic and regularly disposed type of lens siderosis is usually seen in cases which exhibit involvement of the other ocular tissues (cornea, iris, vitreous and retina). Despite the wellknown affinity of the intra-ocular epithelium for ferrous metals, it has been shown by Koeppe, Vogt and Meesmann that in siderosis bulbi the stroma of the cornea as well as the vitreous may be involved. In these cases the discoloration in the lens (siderosis) is found with the narrow beam to be located just behind the anterior capsular stripe or in the region that probably corresponds to the location of the capsular epithelium. Morphologically the deposit may be seen in the form of minute little yellow to brownish colored dots or as larger brownish to reddish accumulations (Plate LXXVI, figs. I, 2, 3). The smaller dots may be generally distributed in more or less of a single plane over the lens in the periphery as well as the pupillary area. The dots are frequently arranged in groups in such a way that a pattern may form. It appears as if clear (unaffected) irregular channels or "gyrus” spaces form between the groups of dots. In certain areas the number of dots may be more numerous than in others and when this is so the clear channels become narrower or are missing. Except for a slight increase in yellowish color, probably caused by reflection from the underlying stained epithe


1282


BIOMICROSCOPY OF THE EYE


lium, the shagreen of the capsule is not affected. The larger accumulations form well defined rust spots frequently visible to the unaided eye (especially in daylight), being from 0.5 to almost 2 mm. in size. This is especially true when, as is frequently the case, the lens is opaque, the sub-capsular area of cortex being vacuolar, thus producing a striking contrast between the rustlike spots and the grayish background. In distinction to the more general arrangement of the smaller dots, the macroscopic discoid spots tend to be distributed wreathlike in a circular manner near the pupillary margin or in the zone of the dilated pupil. This appearance was first described by von Graefe. They also are more likely to be found over radial water-slits or dilated sutures. Although it is not possible to see any of the smaller dots in the epithelium biomicroscopically when they are visualized by specular reflection, their closely subcapsular location does not preclude the epithelial location which has been so well demonstrated histologically. The larger discoid spots are probably formed by a conglomeration of smaller dots, especially in areas where as has also been demonstrated histologically, exuberant growth of the epithelium occurs. The exuberant and stained epithelium may by proliferation extend deeply for a considerable distance in the cortex. This may account for the deeper subcapsular location of the deposits seen with the narrow beam. According to Meesmann the backward displacement of the anterior line of disjunction which he saw in siderosis lentis may also be due to this factor. Macroscopically or with low power it is often seen that zones of discontinuity and the intermediary areas are more blurred than is normal and that their color is more yellowish. This may be due to a “veiling” effect from the subcapsular discoloration. The deeper and posterior parts of the lens are not involved in the process of lens siderosis and hence the ordinary increase of yellowness commonly seen in senility, particularly with nuclear cataract will not be confused with it. Even in cataracta brunescens and nigra, which represent the highest degree of this posterior discoloration in nuclear cataract, the subcapsular zone of the anterior cortex never becomes tinted.

Besides the well-known yellowish discoloration of the iris, it is


1283


INJURIES TO THE LENS

interesting to note that both Vogt and Koeppe have stressed the hitherto little mentioned corneal discoloration and vitreous changes (Plate LXXVI, fig. 3). Uhthoff (1903) described a similar corneal discoloration using a loupe. Siderosis of the cornea was supposed to be a rarity. This was probably due to the fact that it is difficult to see it by diffuse light. When present, it will be best noticed nearer to the limbus. By comparing the color of the corneal parallelepiped to that of the opposite or to that of a normal eye it will be seen that it has a decided yellowish tinge. The normal corneal block or section is bluish gray in color. The cause of the siderotic discoloration in the cornea is probably to be found in the presence of microscopically yellow to green colored dots within the corpuscles of the corneal stroma. In one case Vogt noted a siderotic line in the corneal epithelium. This resembled the so-called senile corneal pigment line. (See Vol. I, page 381.)

Liquefaction and destruction of the vitreous structure when it is not obscured by lens opacification, may also be a feature of siderosis bulbi. Vogt first observed the presence of vivid red pigment deposits and tablet-like white deposits on the scaffold of the disturbed vitreous. Also, using a red-free light source he found in one case a superficial mosslike area in the fovea from which radiating lines extended (retinal folds?). In addition, with the same light source, in this case of siderosis, there was a decided yellow discoloration of the fundus. He was not certain whether this yellow color was due to the discoloration in the lens and vitreous or to an actual siderotic change in the retina.

Up to the time of the recent work of Itoi it was supposed


Bellows citing Itoi’s work stated: "The best explanation is that given by Itoi, who was the first to conceive the idea that electrochemical processes are important in the development of siderosis. To test this hypothesis he showed that a nail placed into the eye of a rabbit quickly becomes rusty, while one connected to zinc placed subcutaneously produces no rust. Itoi justly assumes that electrochemical processes account for this phenomenon, since metal can react with its surroundings only when ions become available because of the electrolytic dissolution tension of the surrounding medium. When the iron is connected to the zinc, the flow of the ions is reversed, and no reaction of the surrounding medium is possible. Mielke extended Itoi’s experiments in order to explain the accumulation of metal in distant places, e. g., subcapsularly. Not only does he agree with Kohlrausch (1932) that there is actually a constant electric current present in the eye (Bestandstrom), but he believes that it flows in just the right manner to direct deposits to such locations. These deposits may occur at any border surface, such as Descemet's membrane or the lens capsule.’’


1284


BIOMICROSCOPY OF THE EYE


that the epithelium had a special affinity for the oxides of iron. In these cells iron compounds formed which may be nature’s way of making the foreign inclusions less toxic.

COPPER IMPREGNATION OF THE LENS

The retention of particles of pure copper within the eye usually causes a severe toxic endophthalmitis, eventually leading to complete ocular destruction. Particles of copper alloys or compounds poor in copper may be tolerated in the eye for long periods but sooner or later tend to produce plating (chalcosis) of the tissues - the cornea, lens, and vitreous being particularly affected. In most of the reported cases in the literature the accident to the eye was caused by explosions, especially of cartridges, grenades, etc., which have containers made up of brass or other copper-containing compounds. The typical picture of chalcosis lentis (sunflower cataract) becomes evident particularly in eyes in which the lens itself suffered no direct injury from the penetrating copper-bearing particle. Although there were a few individual reports of cases having a strange appearance in the anterior part of the lens (Goldzieher [18^5],^°^ Ertl [1907] ^■“) it was Purtscher (1918) who first established that the so-called sunflower cataract was caused by the intra-ocular presence of copper or substances containing it (Plate LXXVI, fig. 4). Jess (19221929) 490 all reported cases up to 1919 and

studied the condition histologically. Vogt (1930-1931) described several cases and gave minute biomicroscopic descriptions of the changes. He listed the following signs as typical:

( 1 ) Shape. The opacity is ring- or disklike, corresponding in size to a medium pupillary diameter. Opaque peripherally pointed spokes of the opacity radiate from the ring or disk so that a kind of "sunflower” figure is formed.

(2) Color. Usuall} the color is grayish green. Hillemanns,^'^ found it to be of an olive to brownish color; Esser,'*"^ a fluorescent green; Haab,'*'’* gray blue; Bleisch,^^® Uhthoff and Rumbaur,”^'^ a brownish or reddish.


1285


INJURIES TO THE LENS

(3) Visibility by retro-illumination. Because of the lack of distinctness when viewed by retro-illumination the opacity was termed an "apparent” cataract.

(4) Localization. Uniformly found in the anterior parts of the lens (subcapsular) .

(5) Color display. Oblique focal illumination reveals an iridescent display in the shagreen fields of the anterior capsule independent of the underlying gray-green "sunflower cataract” behind it. Vogt believed that this finding is inconstant and is to be seen only in progressive cases.

Owing to the peculiar configuration and color, copper cataract has been likened to and called "sunflower cataract.” Some of the earlier writers (Hillemanns and zur Nedden) , not having the advantages of the exact method of localization afforded by biomicroscopy, incorrectly localized the position of copper cataract as either on the surface of the lens or in the middle layers of the lens. However, all recent writers agree that its location is subcapsular or in the anterior lens layers (Fig. 448 A, B) . The only question still to be decided is whether the opacity involves the epithelium of the anterior capsule or the anterior fibers of the cortex or both. Jess considered the deposit to be subcapsular (cortex) stating that the epithelium resists impregnation of copper and that consequently the salt (carbonate) is laid down in a layer just below it. Vogt stated that with the narrow beam the deposit is everywhere of the same sagittal dimension (being so thin as to defy measurement) and that it is located at the posterior surface of the capsular band or in its immediate neighborhood. Also, there is a clear zone between the opacity and the intact anterior line of disjunction. The opacity did not exhibit any fiber or suture design (see Anterior Cataracta Complicata) which might be expected if these structures were involved."' With low power, the figure is plainly visible as a grayish white and slightly

In one case of chalcosis, at the time of extraction of the lens Vogt removed a fragment of the anterior capsule and subjected it to the action of hydrogen sulfide. He found black dots (copper sulphide) grouped around the nuclei in the protoplasm of the epithelial cells. The hyaline capsule and superficial lens fibers did not show any black precipitate. Localization of the copper stain with the biomicroscope supports this finding.


1287


INJURIES TO THE LENS

tinted (blue, green, or even red) star, its center forming a ring or disk. When a ring is present, the diameter of its clear lumen may measure from i to 3 mm. Extending from the central ring or disk are the characteristic rays which taper (retro-iridally) toward the periphery. In Vogt’s cases the width of the ray in its middle portion was from 0.8 to 1.12 mm. With high power it may be seen that the entire visible lens area is covered by fine dots but in the region of the figure they are so numerous, condensed and reflecting that it may not be possible to resolve them as such."' In addition to the fine dotlike deposit, Vogt for the first time reported the presence of small dark spots measuring from 0.02 to o.i mm. These dark "holes” were seen in the pupillary area in the rosette areas. With varying angulations of the beam the)'" appeared to have a gloss characteristic of flattened vacuoles. No pigmentation of copper cataract has been seen posteriorly. However, as has been noted in siderosis, if backward proliferation of the capsular epithelium at the equator occurred, posterior deposit of copper might follow.

The exact explanation for the "sunflower” shape of copper cataract has not as yet been determined. A mild controversy concerning this point was raised by Vogt who disagreed with the explanation offered by Jess. Jess supposed that the ring and its processes was brought about by the fact that the parts of the iris which are located on the lens protects the latter from impregnation by copper. Vogt considered the opposite to be true. According to him, the sunflower figure appears just where the iris could contact the lens. He argues that if Jess is correct, then a figure opposite (negative) to the sunflower cataract would occur, i. e., there would be an intensely opaque disk corresponding to the pupil which should be separated from the peripheral radial sectors by a lighter or clear ring. This would be so because of the protecting seam of the iris which contacts the lens capsule at this point. Radial sector opacities would have their base at the equator, and Vogt points out that in reality the opposite is true. The shape of the copper cataract is generally in the form of a ring, which is located where the pupillary border of the iris contacts the lens. The radial processes would correspond to the normal radial (ridges) marking on the posterior surface of iris. These radial folds with their ridges are finer and closer together in the sphincter 2 one than peripherally where they become coarser; also in the case of the latter their distance from the lens increases (as noted by the greater depth of the posterior chamber peripherally). Consequently the contact of the posterior iris ridges must axially be greater and more extensive than peripherally. It is conceivable that the shape of the manyridged figure of copper cataract (sunflower), which corresponds morphologically to the relief of the posterior pigmented surface of the iris, is caused by the latter. In a case of copper cataract in a boy aged ii, Vogt counted up to i6 rays in one quadrant. On inspection of a corresponding sector of an excised piece of iris from a normal eye he counted about the same number of ridges. This would also tend to support his hypothesis. From the above it would seem that the iris rather than the aqueous furnishes the toxins that induce this form of cataract. He cites a similar observation of Lundberg who found that in napthalene cataract opacification did not occur in the region of an iris coloboma. Also confirming this idea, viz., that the development of the shape of copper cataract depends on the iris, is a case seen by Jess in which after prolonged mydriasis, a second ring appeared.


128S


BIOMICROSCOPY OF THE EYE


The marked coloration of the anterior shagreen (mirror zone) in which a vivid display of colors, red, blue and green, appears, is not found in every case of sunflower cataract. When present the color display, not unlike that seen in complicated cataract, will be found even in areas outside those occupied by the underlying sunflower figure. Hence it must be considered as a phenomenon independent of the cataract itself.

In addition to discoloration of the iris, vitreous changes are seen. The vitreous may be more fluid than normal. This is indicated by the presence of large clear (dark) spaces and by the increased motihty of vitreous trabeculae upon movements of the eyeball. In such cases the vitreous may exhibit a gray-green haze. This haze is due to the presence of dots and dust of great delicacy. These dots are smaller than those seen after inflammation (leukocytes) . At times the gray-green discoloration of the vitreous, which usually gets more pronounced in its deeper portions, even surpasses that of the lens.

SUNFLOWER CATARACT IN HEPATOLENTICULAR DEGENERATION

(Wilson’s disease)

In association with Kayser-Fleischer ring (Vol. I, page 385) a typical sunflower cataract may be found in cases of Wilson’s disease. Vogt considered that the corneal and lenticular pigmentation in this disease may be due to a copper or silver intoxication."' This followed in line with the previous conception of the causation of the Kayser-Fleischer ring of Wilson’s disease as advocated by Rumpel, Spatz, and Siemering. According to Duke-Elder, their theory was "that in hepatolenticular degeneration the body failed

Vogt staled that the solubilitj' of the pigment in potassium cj'anide indicated its metallic nature. Duke-Elder points out that solubility in potassium q’anide is a propert)' common to other metals and to organic pigments as well. Adherents to the idea that the deposit is organic rather than metallic (Jess, Gerlach and Rohrschneider) brought some evidence in favor of this theory’. Jess showed that the pigment fades after long embedding in celloidin (a feature common to organic pigments) and the others were not convinced after spectrographic examinations that it was metal. In a recent biomicroscopic survey, I found that during the stage of icterus and for some time afterward it was possible to detect a faint but definite discoloration (greenish blue to reddish) at the level of Descemet’s membrane in the periphery of the cornea. It never was as marked as that seen in Kayser-Fleischer ring but at the same time this finding is suggestive. In none of these cases was there any evidence of a sunflower cataract.


1289


INJURIES TO THE LENS

to dispose of the metals ingested in food, and that these (copper and silver) were deposited on Descemet’s membrane, while the corpus striatum had a peculiar chemical affinity for them.” Originally both Fleischer and Hall considered that the pigmentation in the cornea was hematogenous. Poe (following Kirbik, Hessburg, and Jess) believed it represented derivatives of bile pigments. As in the case of copper cataract, the sunflower cataract in Wilson’s disease may be missed unless searched for carefully with the biomicroscope. Vogt originally found this condition by chance in a case that was being refracted. The opacity has the same morphologic aspects, localization, and color as does copper cataract.

MERCURY IN THE LENS ( HYDRARGYOSIS LENS)

Recently Atkinson,"' reported for the first time the finding of a colored reflex from the anterior parts of the lens in cases of chronic mercurialism. The importance of this finding from the standpoint of industrial medicine as a diagnostic feature of mercurialism cannot be overemphasized. He stated that "the color of the reflex is deeper in the pupillary area, and in different individuals its color varies from a light brownish gray to a deep rose-brown. The depth of color apparently depends somewhat upon the length of time and the amount of mercury to which the individual has been exposed. Small, round, punched-out defects and cracks often appear in the reflex. These resemble the behavior of metallic mercury. Glass lenses that have been exposed to mercury often present a similar brown reflex when examined with the slit lamp.” The posterior cortex and capsule were unaffected. The presence of reflex seemed to be a constant finding (see Fig. 448 C) . The deposit does not interfere with vision. It is not apparent ophthalmoscopically and depending on its intensity appears as a delicate dull gray haze when examined by ordinary oblique illumination. Intention tremor, affections of the teeth and gums and skin pallor were seen in varying degrees. In a later communication, f Mercury in the Lens, histological, histo ^ Atkinson, W. J., Tr. Am. Ophth. Soc. 40:254, 1942; A??!. J. Ophth. 26:685, July 1943

t Atkinson, W., and Sallman, L. von, Hydrargyosis Lenti, Tr. Amer. Ophth. Soc., 1946.


1290


BIOMICROSCOPy OF THE EYE


chemical, and spectrographical studies were made of lenses removed from a patient with chronic mercurialism in which the colored reflex was present. Although biomicroscopically the staining appeared


Fig. 448 {Continued) . c. Cataract in mercury poisoning.


capsularly or just subcapsularly, in the prepared sections the lens capsule and epithelium did not contain the deposits and were in general normal. Sections of the lens fixed with Cristeller solution showed black or dark brown particles located in the superficial cortex, more numerous in the equatorial regions despite the fact that with the biomicroscope during life the brownish reflex appeared more dense in the pupillary area. The mercurial nature of these deposits was also confirmed by additional microchemical tests. Control lenses similarly fixed were free of such deposits. Spectrographic examination of one of the lenses showing the reflex revealed traces of mercury whereas no mercury was detected in control lenses.


28 Radiation Cataract

I N 1800, Herschel showed that besides the visible part of the spectrum there existed an invisible or "dark” part. The visual part of spectrum, that part which excites the sensation of light in the retina, occupies only a small band in the total spectrum. The invisible part of the spectrum is also subject to the laws of reflection, polarization, and refraction. The wave length of the visible spectrum (red to violet) ranges between 7,000 to 3,500 angstrom units. Above this are the infra-red while below are the ultraviolet, roentgen and gamma rays, etc. Fundamentally as far as the tissue of the eye is concerned only those rays which ate absorbed are harmful to it (Draper’s law, 1879). Those that are transmitted or reflected excite no reaction."* The passage of even intense visible light (free of dark radiant energy) through a plate of glass or water will not raise the temperature of either since no light is absorbed. The same holds true for the eye media. But if a piece of black paper is put behind the above mentioned plate of glass the temperature of the glass will rise owing to the absorption of the light by the black


Duke-Elder succintly explains the affects of absorbed radiant energy as follows; "The periodicity of the longer wave lengths - the infra-red - may be conceived as corresponding in a general way with the movements of the atoms. They are thus absorbed into this periodic system, and their energy finds expression in an increased rate of atomic movement, a phenomenon which is appreciated as heat, and which ultimately results in coagulation of the proteins of the tissue, thus causing a thermal lesion. The radiations of intermediate wave length - the visible rays - finding no sympathetic resonation, as it were, slip through the transparent media without exerting any affect until the retina is revealed. The shorter ones - the ultraviolet - whose frequencies correspond to the intra-atomic periodic oscillations, are again absorbed. The energy they represent is added to the atomic system so that the electrons are made to change their orbit, thus altering the chemical nature of the atom, or are jerked out of the atomic system altogether, thus producing a photo-electrical effect; this results ultimately in coagulation of the proteins and the production of an abiotic lesion. Both these - the thermal and the chemical - are quite distinct, although in the last analysis they are identical, and are dependent upon the transference of energy to the molecules or their parts, with the result that they are shaken apart.”

1291


1292


BIOMICROSCOPY OF THE EYE


paper. By contact the glass gets heated. This may be compared to the process that may occur in the pigment epithelium under the retina when the eye is exposed to intense visible light.

Fortunate!}, owing to the absorptive power of the cornea and lens, only a small part of the invisible rays ordinarily present in our milieu (ultraviolet and infra-red) is able to reach the retina. However, quantitatively this small part (especially the short infra-red rays) actually exceeds in amount the visible rays. The cornea absorbs all radiation above 20,000 A. U. (long infra-red or heat rays) and below 2,900 A. U. (short ultraviolet)."' Consequently when of sufficient intensity, the former can induce a thermal lesion and the latter an abiotic photochemical lesion. The degree of abiotic reaction varies directly with the time of exposure and inversely as the. square of the distance of the source of light from the eye.

That exposure to solar light under certain conditions can result in transient or permanent ocular damage has been known for a long time, e.g., eclipse and snow blindness. Vogt considers that both visible light and short infra-red rays play a role in the causation of eclipse blindness. In pigmented tissues all incident energy is absorbed indiscriminately and is degraded into heat (Duke-Elder). Hence both visible light rays and the short infra-red rays could take part in heating the underlying pigmented epithelium. This in turn by radiation could act thermically on the overlying retina. Vogt experimentally was able to produce retinal "burns” by means of short infra-red rays alone. Since only an insignificant amount of ultraviolet reaches the retina, it is highly probable that this form of energy does not cause the macula alterations that follow gazing at the sun or at an eclipse. Snovz blindness or burn (affecting the cornea and conjunctiva - especially the epithelium) on the other hand is directly due to the effects of the shorter ultraviolet radia The cornea transmits most of the heat rays (infra-red) ranging between 20,000 and 7,200 A. U, and hence these r.ays can reach the lens through the pupil. The lens only absorbs a small percentage (12 per cent) of these rays - particularly those between 13,500 and 11,000 A. U. When these are intense a heat cataract can dei'elop. In addition, the cornea transmits roentgen ra5'S and gamma rays. These rays have extremely short wave lengths- hardly more than i A. U. - and under suitable conditions may induce lens changes. Cataract from this form of radiation appears only after a long latent period.


RADIATION CATARACT


1293


tions. At sea level only the longer ultraviolet rays predominate, i.e., from 3,500 to 3,100 A. U. This radiation in ordinary and normal amounts does not cause any damage, because ontogenetically and phylogenetically it has become *'ph3siologic” for our eyes. However at higher altitudes - especiall}'^ above 6,000 ft. - ultraviolet radiations much richer in rays of shorter wave length (2,900 A. U.) are found. It is these which cause burns of the conjunctiva and cornea. Likewise the abiotic affects to the cornea and conjunctiva after exposure to artificial light (ultraviolet emanations from mercury vapor and arc lamps) is well recognized.

The lens is especiall^'^ vulnerable to short-wave heat rays, absorbing a considerable amount of the infra-red between 14,000 and

11.000 A. U. This is important because 75 per cent of the rays in this band striking the cornea pass through it (Hartridge).

The cornea also transmits the longer ultraviolet rays between

4.000 and 3,200 A. U. and although, experimentally, histologic evidence has been brought forward to indicate that in so doing damage to the capsular epithelium of the lens may result (Verhoeff and Bell, 1916; Duke-Elder, 1929, and others), the consensus today holds that, practically, ultraviolet energy is not deleterious to the lens. Because of the fact that the normal lens appears whitish in ultraviolet light, earlier investigators thought that this might play a role in the production of senile cataract. Clinically well-defined cataracts have not been produced even after prolonged exposure to ultraviolet rays. Actuall} it has been pointed out that in persons living in higher altitudes (richer in ultraviolet) the incidence of senile cataract is not greater than in those living at sea level. In addition senile cataract starts in the peripheral parts of the lens which is protected from the direct affects of radiation by the iris.

FliLorescence. In addition to the properties exhibited by radiant energy already discussed (transmission, absorption, reflection, etc.) the phenomenon of fluorescence remains to be considered. In the eye, this phenomenon is associated especially with the lens. Simply, It means that the lens has the power of changing the wave length of part of the radiant energy incident upon it. Fluorescence in the lens


1294


BIOMICROSCOPY OF THE EYE


occurs when it is subject to the long ultraviolet rays whose length is from 4,000 to 3,000 A. U. - the greatest effectiveness being from 3,900 to 3,700 A. U. When the lens is irradiated with light of this wave length (in a darkened room) it gives off a peculiar greenishyellow glow.

Duke-Elder states: "Here (in the lens) part of the light gives rise to fluorescence, the region of greatest effectiveness being in the long ultraviolet, from 3,500 to 4,000 A.U. This is a phenomenon whose intricate nature is little understood. When light passes through a fluorescing substance, the particles of the substance become light sources themselves, emitting light of a wave length differing from that of the incident light, preponderating!}'^ longer but some shorter. The effect of this phenomenon is regarded differently. Considering that its production implies absorption, Schanz (1915-22) looked upon it as deleterious. On the other hand, from the work of Bunge (1915) who correlated a decrease of fluorescence with an increase in coagulability of lens proteins, it may possibly be looked upon as a protective mechanism, whereby active short waves, which might induce coagulation, are changed largely into long (visible) waves, by which means their energy, being in a more transmissable form is disposed of more safely."

Vogt (1913)®^^ showed that this phenomenon could also occur to a lesser degree in violet and blue light (visible light) as well. He noticed that in violet light the hue of the fluorescence varies with the changing color of the normal lens with age. In the young, in whom the lens is almost colorless, the fluorescence is bluish white.’’" In the case of old people whose lenses become yellowish, especially in the posterior cortex, the fluorescence - appears yellow-green in this light. The }’^ellow color acts as a filter which screens out the blue and violet (cold) hues and passes the warmer ones.

In ultraviolet light the aged lens does not fluoresce as effectively as the young one. In the former the color is faintly yellow, while in the latter it is definitely greenish. The physiologic increase in yellowness with age tends to offset the loss of the power of fluorescence; in this wa}'- protection against the undue action of active short waves is effected."!"

Even in young humans the lens is not entirely colorless and transparent. Calves’ lenses, on the other hand, being highly transparent, do not fluoresce in violet light.

t In this connection, Wald has shown that aphakics have a looo per cent increase of visual acuity in ultr.aviolet light as shown by their ability to read an ultraviolet illuminated Snellen chart invisible to a normal observ'er (phakic).


RADIATION CATARACT


1295


Heat ("Fire”) Cataract; Infra-red Cataract

That cataractous change can occur from exposure to the relatively short-wave infra-red, penetrating radiation from a glowing mass of glass or metal is now a well-established fact (Glass Blower’s and Foundry Worker’s Cataract). Vogt, who did considerable experimental work in the field (1911-1921), showed that the damage to the lens (in experimental animals and man) resulted not from the ultraviolet rays, visible light or the very long heat rays, but from the abundant and predominating infra-red rays (7,500 to 3,400 A. U.), which emanated from these heated and glowing masses."' Hence it is not surprising that men engaged in occupations that expose them to this kind of irradiation (glass blowers, foundry workers, blacksmiths, welders, etc.) are liable to suffer from lens changes. As will be seen, these changes form a specific type of cataract, and hence they bear the name “glass blower’s” or "fire” cataract.

The amount of ultraviolet and visible light that emanates from these sources is less than that found in ordinary daylight and hence can be considered of little importance. In 1918 Vogt succeeded for the first time in making an apparatus with special filters and optical system that made it possible to obtain short-waved infra-red rays in sufficient quantity. After an exposure of three hours, cataract developed in experimental animals (rabbits). With strong doses he was able to produce anterior lens changes as well as the characteristic


Two kinds of invisible infra-red (heat) irradiations must be recognized. First, the long (nonpenetrating) waves, those over 24,000 A. U. and second, the shorter waves, from 24,000 to 7,500 A. U. The long-waved rays are absorbed by the tear film and the corneal surface. Exposure to them results in a sensation of warmth and eventually if intense to conjunctivitis and keratitis (thermal reaction). Long nonpenetrating infra-red is radiated in large amounts by stoves and sources of artificial light (incandescent bulbs). The shorter infra-red rays predominate in glowing masses of glass or metal. Vogt showed that these pass through the cornea and are absorbed by the iris and especially the lens. Hence he called them "penetrating infra-red rays.” In other words it is only a heated body giving off a red glow (500 degrees R or over) that is able to radiate infra-red rays sufficiently small in wave length to penetrate the media and affect the lens. Practically, the fact that persons working in temperatures even higher than those in which glass blowers or foundry workers are subjected to, do not develop the typical "fire” cataract speaks for the specificity of the shorter "penetrating” infra-red rays.


1296


BIOMICROSCOPY OF THE EYE


posterior cortical changes. Cataract developed more readily in the older animals and in those that were pigmented. The former findings coincide with the fact that most of glass blower’s cataracts in humans were found in older persons; not entirely because of greater number of years of exposure but rather that old lenses absorb more of the infra-red rays. This is further evidenced by the frequent finding of nuclear changes (cataract nigra and brunescence) . The average age for the appearance of glass blower’s cataract varies between 5 5 and 60 years. This is considerably lower than that found in senile exfoliation of the capsule. Because it was easier to produce cataract in pigmented animals (although later Vogt did so in albino animals also) , the famous controversy between him and Goldmann arose. Vogt considered that the action of the short infra-red rays was specific to the lens. Goldmann held that the lens changes were secondary'- to overheating of the iris and also to increase of the temperature of the posterior chamber following the rise of general body temperature. He based his contentions on the difficulty of producing cataracts with exposure to infra-red in albino rabbits and even in the pigmented species when the iris was protected. Vogt admitted that the heat absorbing power of the pigmented iris could play a role in raising the temperature in the anterior chamber and consequently that of the cornea, but felt that this would only augment the direct action of the irradiation to the lens. Experimentally and clinically the point that the lens changes in the beginning are located in the pupillary zone both anteriorly and posteriorly, and that the neighboring ocular tissues (cornea, iris, and vitreous) are manifestly not affected, also tends to confirm Vogt’s

The question has been raised whether the type of changes produced in animals by large single or intensive doses are comparable to those found in glass blowers and foundry workers who are exposed to fractional doses, extending over long periods. (In practically all the reported cases the characteristic lens changes of glass blowers and foundry workers cataract never appeared in individuals before 15 or 20 years of employment in these occupations.) Clinically Vogt was able to produce by irradiation (in a case of an intra-ocular tumor) with short infra-red rays the typical changes of heat cataract. The eye was irradiated with 'fractional doses for long periods from one direction - so that the one and the same part of the lens was exposed to its effects. After the fourth treatment typical anterior subcapsular homogeneous dust-like opacities appeared in the area irradiated. With further exposure the opacities thickened and six months later the whole opacity was pushed deeper into the cortex by new clear fibers. Meesmann, employing small and repeated doses of infrared in rabbits produced axial cataract in the posterior cortex - similar to that found in glass blower’s cataract.


RADIATION CATARACT


1297


idea that the damage results principally from the direct action of the rays on the lens. From the standpoint of biomicroscopy the alterations in glass blower’s and foundry worker’s cataract may be enumerated as follows:

(1) Detachment of the superficial lamella of the anterior lens capsule (solutio laminae superficiahs)

(2) Posterior and anterior axial subcapsular opacities similar to saucer cataract

(3) Superficial (anterior) gray radial striae (wreathlike opacities [Schlafen])

(4) Nuclear cataract (especially cataracta brunescens)


DETACHMENT OF THE SUPERFICIAL LAMELLA OF THE ANTERIOR CAPSULE


Although detachment of the superficial layer (lamella) of the anterior capsule (Solutio Laminae Superficialis - Fire Lamella) is not found in every case of heat cataract, when present it is diagnostic of glass blower’s cataract. It has not thus far been reported in any other condition. And, like senile exfoliation, it has never been found on the posterior capsule. Occasionally it may be found long before any other lens changes are noted (especially the characteristic anterior or posterior polar opacities) , but in most instances it is accompanied by cataractous changes of varying degree.

Of the cases reported in the literature, the ages of the patients in whom fire lamellae were found ranged on the average between 50 and 60 years.'*' The youngest (Schnyder '’”^) instance occurred in a 42-year-old smelter.f Elschnig was the first to describe the detachment and to interpret it correctly as an occupational disorder in glass blowers. However, he called it detachment of the zonular lamella; today it is realized that it probably does not involve the zonular lamella, the location and attachment of which is more equa

â– By comparison it will be seen that the age range for senile exfoliation (which though affecting similar parts of the capsule is morphologically different in appearance) is notably higher.

1 In the case of smelters or those exposed to the glow of liquid metal the earlier appearance o re lamella (and other changes) may result from the higher temperature and more intense irradiation of penetrating infra-red rays to which they are exposed.


1298


BIOMICROSCOPY OF THE EYE


torial (page 1331). Meesmann first described the appearance of an actual detachment of the zonular lamella after trauma (page 1332). Actually the part of the capsule that separates in heat cataract starts


A B


Fig. 449. Heat cataract, a. Frontal view. b. View by optic section.

just at the place where the zonular lamella ends (a weak transitional zone) and extends axially in a more or less concentric way retroiridalty nearl)’- to the pupillary zone (Fig. 449 A, B). Just as in senile exfoliation, a somewhat opaque pupillary disk may exist. As mentioned previously, the morphologic difference between firelamella and senile exfoliation ma}'^ only be one of degree. In senile exfoliation, the separation is more delicate and is characterized by fine crumbling powder) or gray flak) particles. These particles, being extremely light in weight as compared to their size, float freely like inflammatory precipitates in the currents of the aqueous; they may become attached to the pupillary margin and in certain instances may clog up the filtration angle and produce increased intra-ocular pressure (glaucoma capsulare).

In detachment of the superficial lamella in heat cataract the separated pellicle is thicker, continuous, and like a glass membrane it is reflecting. (See detachments of Descemet’s membrane, Vol. I, page 422.) One might compare the detached portion, which is directed


RADIATION CATARACT


1299


toward the periphery to a transparent sail which can be agitated in the anterior chamber by eyeball movements (Fig. 449 A) . The detached membrane may be folded; in a case described by Vogt the dorsal surface was sprinkled with pigment.

In senile exfoliation the ends of the separated, pellicle are directed axially. In contrast to senile exfoliation in which the detached portions are opaque and easily visible, it is usually impossible because of its transparency to decide exactly at what point the fire lamella has become detached. Axially the detached membrane may extend up to a pupillary disk, and the edges may or may not be raised. Schlapfer also reported in glass blowers the presence of a fine line running concentric to the dilated pupil (without definite separation of the lamella). This line, which may represent the beginning of rupture or separation of the lamella, was delicately pigmented.

The first histologic preparation of fire lamella was made by Vogt who studied two cases. He found that the separated lamella (which in one case was about one-half the thickness of the entire hyaline capsule) contrary to the usual biomicroscopic appearance, varies in thickness. However, Elschnig in his biomicroscopic description found that lamella is not homogeneous but is composed of fine parallel and horizontally directed lines or subdivisions (parallel stripings) . This form of laminated striping or separation of the hyaline capsule into subdivisions has also been seen in histologic preparations of other types of cataract (e.g., senile) and suggests solution of the cement substance between the laminations. Evidently such a process, while it is not specific, is more marked in the fire lamella. The condition of the underlying epithelium varies. In some cases its nuclei are deformed, and the cells are fusiform. The underlying lens fibers exhibit varying degrees of vacuolar destruction.

ANTERIOR AND POSTERIOR SUBCAPSULAR SAUCER-LIKE OPACITIES

The fact that subcapsular opacities (especially those of the posterior pole) are significant for heat cataract was proved experimentally by Meesmann and by Vogt. By using fractional doses of penetrating infrared over long periods of time in experimental animals (rabbits), Meesmann was able to produce posterior polar lens


1300


BIOMICROSCOPY OF THE EYE


opacities and thus was able to simulate this characteristic type of opacity so frequently found in glass blower’s cataract,’*'’ Using more intense irradiation over shorter periods of time Vogt also demonstrated experimentally in rabbits that cataractous changes appeared lirst where the light bundle contacted the lens (i.e., the anterior cortex) and then where the rays leave the lens or the posterior cortex, In his animals, homogeneous fine dustlike opacities appeared in the anterior and posterior polar regions soon after irradiation. Larger vacuoles only appeared much later. The opacities preferred the region of the sutures (a finding seen in many other types of cataract, i.e., complicata, senilis and traumatica) . As a rule after an early progression and providing total cataract does not occur the infra-red (experimental) opacities become stationary. However, as in traumatic cataract, the layer of opacities may be pushed deeper into the cortex by the ingrowth of superficial clear fibers. With this type of irradiation the nucleus was relatively immune. In a human subject (vide supra) Vogt was able to produce similar circumscribed and permanent opacities.

The finding of subcapsular (polar or parapolar) opacities as a manifestation of glass blower’s cataract has been verified by numerous authors. Ocular complications, i.e., iridic changes, precipitates in the anterior chamber and especially in the vitreous, are absent in heat cataract. This again would tend to strengthen the proposition advanced by Vogt and his school that strictly speaking infra-red cataract is not primarily a complicated cataract in the sense that it is caused secondarily from the effects of heat on the surrounding tissues. The differential diagnosis between senile saucer-shaped opacities (in the absence of anterior lamella separation) may be difficult. Also since most heat cataracts occur in older individuals, the presence of well- developed ordinary senile cortical and nuclear

The opacity was radial to sutures of the posterior cortex. Vogt believes that this area is especially vulnerable. Legge cited by Bellows points out that "the region of the posterior pole is involved first because the waves are refracted by the cornea and lens and become more concentrated there. This concentration is enhanced by some reflection from the concave posterior surface of the lens.” In the experimental animals the opacities were in the beginning dust-like and with higher power seemed to be of vacuolar nature. Similar to traumatic cataract (remotio) and zonular opacities, Vogt found that after some months they were progre.ssively displaced deeper and deeper into the cortex.


RADIATION CATARACT 1301

cataract may so obscure the picture that, as mentioned above, in the absence of anterior lamella separation a differential diagnosis from the standpoint of morphology may well be impossible. One point may be brought out in this regard - it is not common in senile saucer cataracts in the early stages for subcapsular opacities to be limited to the polar regions.

Both Schnyder and Vogt have emphasized that posterior opacities, in heat cataract may be arranged in a double or triple layer (meniscus form). Each successive layer from before backwards increases in density so that as a rule the posterior one is the thickest. Each layer, composed of vacuoles and flaky material, is thickest axially and flattens out peripherally where, as small dots and lines, it gradually loses itself in the clear lens substance. Frequently, the separation of these layers by lucid intervals is greatest axially, the peripheral ends tending to converge. The more delicate and most anterior of these layers usually does not extend as far peripherally as do the deeper ones and consequently, in diffuse light circles of opacities may appear. Considering the age of these patients it is not surprising that the posterior subcapsular opacities are commonly tinged yellow.

The anterior subcapsular opacities are more delicate and in the beginning are composed of fine dots, which under higher powers of observation and retro-illumination may have a vacuolar appearance. Larger clear vacuoles are seen frequently in association with the finer opacities. As is common in anterior saucer opacity the changes at first appear (under low power) as a small area of axial blur with one or more radial processes or stripes extending from it. These radial stripes apparently follow the direction of the lens fibers. With the narrow beam some of the finer deposits may be directly subcapsular but most often they will be found condensed at the anterior disjunction line.


SUPERFICIAL (anterior) GRAY RADIAL STRIAE

In 1930, Rehsteiner and Schlapfer described the presence of superficial gray radial striae situated about midway between the lens vertex (axial) and the equator (Fig. 450). Unlike the "fire”


1302


BIOMICROSCOPY OF THE EYE


lamella they are not specific for heat cataract. Schlapfer considered the striae as a new finding in glass blower’s cataract. These authors found them in slightly more than half of a series of 59 glass blowers


Fig. 450, Heat cataract. Radial striae. (After Vogt.)

and only in a fifth of persons whose occupations did not entail exposure to infra-red. In contrast, Abramowicz reported these striae in 90 per cent of 240 persons, all of whom gave no history of occupational or other prolonged exposure to heat. Dilatation of the pupil is usually necessary to observe the striae. The stripes are somewhat poorly defined and hence can be overlooked easily. "When the entire pupillary area is observed by strong diffuse light, it will be seen that they form a ring or wreath more or less concentric to the pupil. The ring is composed of delicate radiating gray lines, i.e., running at right angles to the pupillary margin. These lines especially those which are nonpigmented, are reminiscent of the retro-iridal lines (page 1023).

Vogt localized the striae as subcapsular since they were covered by the shagreen of the anterior capsule. Since the significance of these radiating structures is not entirely understood, we can only consider them as pertinent to heat cataract when a positive history of exposure to the prolonged action of penetrating infra-red is established.


RADIATION CATARACT


1303


NUCLEAR CATARACT

Most of the observers of heat cataract agree that nuclear sclerosis and nuclear cataract are features of this syndrome. The sclerosis, which may involve the deeper cortex, may explain the subcapsular location of the opacities mentioned above, since it could prevent further extension into the cortex. Also related to the sclerosis and nuclear opacification is the increased yellow discoloration of the deeper parts of the lens. (This causes the yellow or brownish color of the posterior cortical opacities which necessarily are viewed through it.) In heat cataract, the discoloration seems to precede by a considerable amount of time that found in very old persons. It should be noted that the appearance of the nuclear cataract in this condition differs in no way from that ordinarily seen in senility (page 1147). Nuclear opacification (especially the rubra type) in glass blower’s cataract at times may precede the formation of the well-known posterior saucer opacities with which it is usually associated. One of the advantages of the narrow beam as afforded by the biomicroscope is the ability to detect early clouding in the nucleus. It begins as a grayish condensation within the fetal nucleus and gradually extends outward in both directions. Later it is characterized by a more diffuse central haze, which is separated from the adult nucleus band by a clear interval. The tendency toward deep discoloration (posterior cortex) is marked (cataracta brunescens and rubra) with a gradual transition to yellow and greenish shades anteriorly. However, nuclear cataract by itself can in no wise be considered as a form of heat cataract unless a positive history of exposure to infra-red, other changes such as anterior and posterior polar opacities and, above all, fire lamella are present. Only the last finding is irrefutably diagnostic.


"'According to Berner the absorption of infra-red in the nuclei of lenses in old horses and cows is much greater than that of young animals. This could explain the reason for the nuclear involvement in glass blower’s cataract since it generally was not found in the experimental infra-red cataracts in growing rabbits. Perhaps the young lens containing a high percentage of water absorbs less infra-red than does the older lens with its sclerosed nucleus.


1304


BIOMICROSCOPY OF THE EYE


Roentgen (X-ray) and Radium Cataracts

The most distinguishing features of the lens changes following irradiation by x-rays or radium lies in a prolonged latent period (one-half to one year in experimental animals and from 9^4 months to 8 years in man) between the time of exposure, the appearance of cataract, and the progressive nature of the opacities themselves. These two factors have been verified both experimentally and clinically. In this way radiation cataract differs markedly from infra-red cataract. In animals, lens opacities preceded by ephemeral iritic irritation appear a few days after infra-red irradiation. Whereas the opacities (very similar morphologically to those of infra-red) following x-ray and radium first become visible only after many months, even in cases in which the exposure has been sufficient later to produce total cataract.

The failure of earlier authors to recognize the vulnerability of the lens to this kind of irradiation lay in the fact that they were unaware of the long latent period. The older observers were hampered by the lack of the biomicroscope. With this instrument it has been possible not only to observe the finest alteration but also to determine whether they are progressive or not. Vogt has stressed the important differential diagnostic point between heat and x-ray cataract. In the case of heat cataract, provided a total cataract does not form immediately, the opacities do not tend to progress but rather may be displaced deeper by new anteriorly placed clear fibers (similar to remotio cataract) . Whereas x-ray and radium cataracts, when once started, continue to progress and advance deeper - an indication of epithelial devitalization.

It has in addition been demonstrated experimentally that relatively, the young lens is more sensitive to the action of these rays

Since the effects of both these forms of radiant energy on the lens are similar, they will be considered together. In eight experimental trials (Schiez cited by L. Peter there were no morphologic differences found between the cataracts caused by radium or x-rays. Bellows, citing Desjardin, states; "Histologic alterations likewise are quite similar except that degenerative changes in the blood vessels are more prominent after radium because the slight distance between the radium and the eye permits the beta rays to exert their intense short-range influence."


RADIATION CATARACT


1305


than the lens in older animals. This seems to be directly opposite to the effect seen after infrared irradiation where absorption in the lens increases with age. Whether the damage to the lens from x-rays and radium is direct or secondary through their effect on the ciliary body is still unknown. Because the opacities appear axially in the posterior subcapsular region some have leaned toward the latter conception. This would not explain the frequent early finding of anterior subcapsular changes. Histologically Vogt was unable to find any changes in the equatorial regions. Reese in a histologic study of i6 radiation cataracts removed intracapsularly in humans, found migration of the epithelium posteriorly at the equator. He confirmed the findings of others, i.e., that zones of subcapsular (cortical) vacuolization and fiber destruction occur. In addition he found dense plaques of subcapsular scars resulting from metaplasia of the epithelial cells.

Judging from the illustrations in the literature of experimental x-ray and radium cataracts there appears to be little difference in the morphologic aspects between them and the changes in animal lenses resulting from exposure to penetrating infrared (or some of the other exogenously caused cataracts). In both, the opacities are fine and are located subcapsularly predominantly posteriorly. However, Vogt has pointed out that in infrared cataract the opacities are more dustlike and homogeneous.

Biomicroscopic Appearance of X-ray and Radium Cataract

According to the cases reported in the literature there seems to be considerable variation not only in the morphologic aspects of the lens lesions but also with regard to the dosage of radiation necessary to produce them."' Although the tendency to cataract seems less in

Lina Peters, who reviewed the experiments of Sching and Rados (who were unable to find opacities - possibly because they did not observe their animals for a sufficient length of time nor did they present biomicroscopic findings) was able to produce cataracts in rabbits (6 months to i year old). She employed doses varying from i to lo skin erythema doses (1.5 S.E.D. = 55 o r). As is the case in heat irradiation, an ephemeral exudation reaction appeared in the anterior chamber within three days but cleared promptly. It was not until several months later (this interval depending on the strength of the irradiation) that typical posterior and anterior subcapsular opacities and vacuoles appeared.

Numerous reports are at hand concerning the dosage and latent period of irradiation by


1306


BIOMICROSCOPY OF THE EYE


adult lenses this does not mean that they are immune. Depending on the length of irradiation, changes appear even in the aged lens. Whether or not irradiation hastens the progression of minute and

incipient senile cataractous changes is as yet not known. According to Milner, the gamma rays of radium are more damaging to the lens than are the beta (undoubtedly because of the lesser penetrating power of the latter, since the beta rays are actually far more destructive to tissue) .

With the biomicroscope the early lens opacities, like those in heat cataract, appear in the axial region subcapsularly and predominantly posterior. However, no strict rule can be made because in some instances changes are first observed in the anterior polar regions. The most characteristic lesion is that of a thick dense disklike opacity located subcapsularly or deeply cortical at the posterior pole (Fig. 451). This disk, seen best in its entirety by strong diffuse illumination, may be composed of one or more layers (one in front of the other) so that from in front they appear like concentric rings. With the optic section this layered structure when present is seen easily. The opacity is usually densest in the center, gradually fading out in the form of small white points (sometimes as radiating processes) in the clear surroundings. Peripherally the edges may converge toward one another and fuse, tending to take the shape of a flattened convex lens. As already mentioned this meniscus form of opacity is not specific for x-ray or radium cataract but may occur in


Fig. 451. X-raj' cataract.


x-ray and radium in which cataract appeared in man. The minimal dosage that is able to produce cataract in man is still unknown. The differences in this regard being so great suggest individual variations and susceptibilities. Clapp collected 34 cases in the literature, the latent period of which varied from 9’/^ months to 8 years. Vogt cited three of his cases aged 7, 40 and a child of 12 years, all of whom were irradiated because of tumor or suspicion of tumor. The doses were 4.5 S.E.D. applied in three to four sessions. In all, posterior subcapsular cortical opacities, followed later by anterior ones, appeared in at least one year following the last irradiation.


RADIATION CATARACT


1307


posterior saucer (senile) cataract, in complicated cataract and in glass blower’s cataract as well. In composition, the opacity resembles saucer-shaped (senile) cataract rather than cataracta complicata - being composed of a mixture of fine crumblike opacities and vacuolar structures. Like saucer-shaped cataract and unlike complicated cataract, the opacities tend to be limited to definite layers, the borders of which (anteriorly and equatorially) are sharply demarcated. In older individuals, as is to be expected, these posterior cortical opacities usually have a yellowish tinge. Anteriorly the axial subcapsular opacities vary from case to case. Usually, they closely resemble those described under the heading of anterior saucer-shaped cataract (page 1141). Being composed of delicate dots which by retro-illumination have a vacuolar appearance, they have a definite tendency to radiate (according to the sutures and direction of the fibers). In extreme cases condensation of the anterior opacities in the middle layer of the cortex may also result in the formation of a dense central anterior disk (Vogt, Peters, Meesmann and Reese) . In one case, in a young girl whose eyelids were irradiated for vernal catarrh, the cataract became total two years following a single course of four screened radium treatments. After the second treatment several small skin and conjunctival telangiectases appeared. There also was loss of cilia and a mild eyelid dermatitis. In other cases keratitis, developing into an intractable keratitis bullosa have been noted. All in all one should be extremely cautious in the employment of these modalities (x-ray and radium), especially in cases where simpler and less dangerous therapeutic measures are available.

Electric Cataract (Cataracts from Lightning and

Electric Shocks)

Cataract which results from the effects of natural electricity (lightning) differs in no way from those following electric shock with ordinary ranges of generated voltages. Recently a comprehensive discussion of electric cataract was given by Gabrielides (1935) and Skydsgaard (1939). The former reviewed the published cases from 1900 to 1935. Bellows and Chinn (1941) have written an ex


1308


BIOMICROSCOPY OF THE EYE


tensive paper on the pathogenesis of electric cataract. From the work of these and others it appears that (i) Cataract may result even when the current enters the body distal to the eye (e.g., by way of the extremities). (2) There appears to be no correlation between the degree of lens opacification and the voltage of the current."' The exact significance in this regard as to the duration of the shock which must vary in case to case is still unknown. ( 3 ) According to the cases reported a latent period extending from i to 19 months may precede the appearance of any lens alteration. (4) Corresponding in general to complicated cataract, and radiation cataract in particular, the lens changes occur in the anterior and posterior subcapsular regions of the cortex. Anterior capsular involvement has been noted.

Gabrielides distinguishes between the lens changes resulting from high tension burns and those from lightning by the fact that in the former the opacification tends to favor the anterior subcapsular regions and the capsule itself. From the standpoint of the biomicroscopic appearance alone it is doubtful whether it would be possible, in the absence of a history of exposure, to make an etiologic diagnosis. The general form and constituent character of the opacity seem to vary according to the individual.

Koeppe described a case occurring in an electrician in whom contact with the right temple occurred. After three months bilateral changes in the eyes were noted. Vesicle-like protrusions of the anterior capsule and epithelium occurred, especially at the periphery. These were seen better in the zone of specular reflection and by retro-illumination. The author was reminded of keratitis vesiculosa by their appearance. The vesicles had a central silvery transparency and dark contours. Between the vesicles many smaller polymorphic opacities were present. The nucleus was more or less opacified, the

For example, Terrien (1908) reported a case where an almost complete cataract developed in the right eye 18 weeks following a shock of 500 volts, the point of contact of the current being the right forehand. Lens opacification began after a latent period of 12 weeks. Rollet (1928) described a case which was subjected to 80,000 volts (place of contact, right parietal region). Only subcapsular opacities were found after a latent period of one month. The cataract reached maturity after 10 months. In tw'O other instances (Koeppe, Skydsgaard) the lens opacities were more marked in the eye opposite the point of contact of the current.


RADIATION CATARACT


1309


posterior cortex being free of vacuoles. After one year the visual acuity became worse and the vacuoles less abundant but longer, and between them smaller opacities with angular contours were present which extended deeper into the cortex especially in the region of the sutures.

Gabrielides reported a case in an electrician who attempted suicidal electrocution. One year later the lenses in the pupillary areas appeared opaque and somewhat protruding. The opacity was irregularly polygonal, white, thick and homogeneous. Around the central opacities one could see others located immediately beneath the capsule. They were linear, white, of a silky appearance and crisscrossed indiscriminately in every direction in such a way that the whole periphery of the lens seemed to have been occupied by a spider web with small white enmeshed dots. This later appearance has also been seen by Skydsgaard who described a network of fine linear opacities resembling cotton fibers. Their arrangement had no relation to the lenticular structure.

Recently reports have appeared in the public press concerning the development of cataract in workers in the field of atomic energy.


29 Secondary Cataract

Secondary Membrane; After-cataract; Cataracta Secundaria

T he term "secondary cataract” is used to describe capsular and lenticular remains as well as the products of degeneration and regeneration which are found in the wake of extracapsular cataract extraction or after spontaneous absorption that occurs following hypermaturity or traumatic perforating injuries of the lens. Besides purely lenticular derivatives in certain instances inflammatory exudates (membranes) and pigment usually derived from the iris may be included. Primarily the formation of secondary cataract depends upon the retention of the anterior capsule. The retained posterior capsule by itself (which can be seen with the biomicroscope as a delicate gossamer structure) ordinarily does not obstruct vision - although in certain instances after long periods of time it also may undergo degenerative changes and may become sufficiently opaque to require discission. However, it is when opaque anterior capsular remains adhere to the posterior capsule that we have all the necessary components of a secondary cataract. The fact that secondary cataracts and membranes are multilayered can easily be demonstrated with the biomicroscope (optic section) . Frequently, these layers (anterior and posterior capsule) are separated in places by lucid or opaque material and extend parallel to one another. In such cases not only does the retained soft lens matter (cortex) become encapsulated and no longer be acted on by the lytic aqueous, but also "a partial regeneration from the capsule-containing epithelium is possible.”

For the sake of clearness this designation should not be employed to describe cataracta complicata as some writers have done.


1310


SECONDARY CATARACT


1311


That such regeneration occurs has been proved experimentally in animals. Clinically it is manifested in the equatorial regions by the so-called "ring of Soemmerrung.*'^^ Histologically this more or less circular torus-like opacity consists of remnants of retained lens matter (encysted by capsular remains) and newly formed or regenerated lens substance derived from the capsular epithelium. The character of the newly formed or regenerated lens substance varies from case to case and differs from that of normal lens fibers.

It may consist of opaque or fairly lucid material, but with the narrow beam - even when fairly clear ophthalmoscopically - it can be seen to be composed of a relucent fluid-like granular substance and hence optically is disturbing to vision (Plate LXXVII, %• 4 ) •

In a sense one might be tempted to differentiate between secondary cataract and secondary membrane (Plate LXXVII, fig. 3). An important point of difference between the two is the presence of retained or regenerated lens fiber substance in secondary cataract. Clinically the distinction may be difficult to establish.

The importance of careful biomicroscopic examination of all secondary cataracts and membranes cannot be overemphasized. In Vogt’s opinion, to neglect their study nowadays by means of the optic section, especially before operation, is tantamount to negligence.f It is only by such careful study that one can decide not only as to the feasibility of the type (extraction or discission) and time of operation but also as to the point where the capsule should be grasped or cut. When, soon after extracapsular extraction, free soft lens matter is present and there is no herniation of the vitreous, and according to the indications, one does not decide on immediate

It should be noted that with time opaque material may become lucid or conversely, that 0 Owing discission apparently lucid lens substance may become opaque. So that when the secon ary cataract consists of any considerable amount of lucid substance it might be advisable some type of extraction procedure rather than discission since this lucid material fw ich opacifies later) may become surrounded by vitreous - a state of affairs not conducive of the opaque lens substance,

b ^ r surgeon does not regard the operation on secondary cataract and mem will'^ ’Shtly. Being fully aware of the technical difficulties and complications involved he we come and uniformly employ this means of examination. Fortunately with the wider eli^inat'd°^ lotracapsular extraction this troublesome chapter in ophthalmic surgery will be


PLATE LXXVII


Fig. I. Secondary (after) cataract with adherent iris almost secluding the pupil. The iris in the pupillary area is drawn forward and folded.

Fig. 2. Secondary membrane (after extracapsular cataract extraction) irregular pupil. Marked iris atrophy. Note cystic degeneration of the capsular epithelium and crumblike bodies.

Fig. 3. Secondary cataract (after extracapsular cataract extraction). Note irregularly round opening in the anterior capsular remains exposing the more delicate posterior capsule behind it.

Fig. 4. Secondary cataract. The area between the anterior and posterior capsular remains is occupied by cholestrin crystals.

Fig. 5. Secondary cataract. Cystic degeneration of capsular epithelium (Kugeln) .

Fig. 6 . Secondary cataract. Cystic degeneration of the capsular epithelium. At the left the small grapelike or egg spawn cysts are viewed by light reflected from the fundus.


1312




SECONDARY CATARACT 1315

irrigation of the anterior chamber, the biomicroscope will permit one carefully to observe the rate of absorption and to judge the optimum time for operation. Before extraction of a secondary cataract biomicroscopy will reveal folds and thickenings in the membranes, places where proper purchase can be obtained for grasping the capsule. It will show whether iridic adhesions are present and which ones should be freed to avoid dangerous and painful traction.

I once witnessed a demonstration in which almost the entire iris (atrophic ?) was pulled out with one quick jerk. This was followed by severe hemorrhage, glaucoma, and eventual loss of the eye. In cases where a discission is planned, the biomicroscope will show readily the degree of opacity (number of layers), as well as the thickness and the direction of traction bands in the secondary membrane; this will indicate the place of the incision (usually where the membrane is thinnest), its direction (preferably at right angles to the direction of the lines of traction) and incidentally the type of cutting instrument to be employed (Ziegler, Wheeler, or de Weaker types) .f Extensive synechiae and the appearance of vessels in the secondary cataract (especially the latter) should warn of the possibility of inflammatory membranes (Plate LXXVII, fig, 2). Vessels should be charted so that they can be avoided during operation, if this is at all possible, to reduce the hazard of hemorrhage. Such membranes may be very thick, and the futility of early operation upon them is well recognized. Oscillatory movements of the beam will frequently demonstrate herniation of vitreous into the anterior chamber. This is found uniformly after discission. It may appear as a definitely outlined globular mass protruding through openings in the capsule and trembling with movements of the eye. Prolapsed vitreous is always more relucent than normal, the framework being more relucent or reflecting. Fine pigment deposits are usually seen. At times after a perforating injury or needling, a tract'

After atropinization (with relaxation of zonular traction) small folds in the membrane will show the direction of the strongest traction.

+ The choice of operation is governed to a large extent by the thickness of the secondary cataract. In the thin membranous types, with a Wheeler knife discission may be adequate whereas in the thicker types if extraction is not feasible a De Wecker or Berens scissors may be indicated. • ’


1316


BIOMICROSCOPY OF THE EYE


of vitreous. substance may be seen extending to and adherent to the incission scar in the cornea (Vol. I, Plate XXXIX, fig. 4).

It has been suggested by some (and denied by others) that anterior prolapse of the vitreous is conducive to secondary glaucoma. In the writer’s experience presence of prolapsed vitreous, considering its frequent occurrence, is in itself not a sine qna non of secondary glaucoma. However, prolapse or anterior herniation of the vitreous into the anterior chamber may be factors in the causation of secondary glaucoma providing its adherence to the surface of the iris or posterior surface of the cornea induces peripheral anterior synechiae. Delayed reformation of the anterior chamber, incarcerated iris pillars, or the presence of an iris collar at the base of the iridectomy are contributing factors. Of no less importance is the biomicroscopic examination of the eye after discission or extraction of cataracta secundaria. This will serve not only to confirm the technical success or explain the failure of the operation, but also may help in the explanation of ensuing complications.

Clinically the biomicroscopic picture observed in cataracta secundaria varies greatly, but certain features require individual consideration. These have to do with special appearances of the capsule - e.g., iridescence, folds, and the so-called "dark slit” or "rent” line - and those changes which are associated with lenticular regeneration and degeneration - e.g., Soemmerrung’s ring, Elschnig’s spheres, crumblike bodies and lentoid forms, cholesterol crystals, and pigmentary deposits. Not all these changes will be found together in every case but it is not unusual for a single individual to show several of them mixed together or irregularly distributed. Except for Elschnig’s spheres it is not possible to identify proliferated epithelium or the formation of new layers of hyaline capsule; these changes are seen only histologically.

Folds and Iridescence. As previously mentioned, the degree of opacification and toughness of the retained capsule (especially the anterior) varies greatly; areas of thickened and whitish capsule may be interspersed by others where the capsular rests are thin and only slightly relucent. It is not uncommon to find densely white thickened


SECONDARY CATARACT


1317


and folded capsular remains near the margin of the iris. Directing the beam laterally to the borders of the thickened and opaque capsule and into the vitreous, the edges may be made to glow red (Plate


Fig. 452. Delicate (thin) secondary membrane with cystic excrescences, a. Diffuse illumination.

B. Optic section. (After Vogt.)


LXXVII, fig. 6). Frequently a thinned capsular pellicle will seem to be pulled out by traction and as a result has small radial folds. These small folds must not be confused with the large coarser ones seen in heavy opaque membranes which are usually associated with, and caused by, the traction of firm iridic adhesions. At times some

This phenomenon has been mentioned before, for example, in the case of the vacuoles within a cortical spoke and in the margins of ruptures of the posterior capsule. This glow is caused by reddish light (divergent rays) reflected from the fundus (as in ophthalmoscopy), and is best seen by observation along the beam’s axis.


1318


BIOMICROSCOPY OF THE EYE


of the small folds show branchings. They are difiScult to see in direct focal illumination, especially against the background of the underlying substratum. They may be more distinct by indirect illumination. The small folds in specular reflection will show double lines of reflection and when numerous, polychromatic iridescence. This color display is seen only in the mirror zone and usually is associated with the capsular shagreen. Despite this, Vogt considered that the refringence is dependent on the presence of capsular epithelium. Contrary to this conception is the fact that the color display may occur occasionally even when thick folded opaque membranes are covered by a delicate thin layer of tissue. This may suggest that the interference phenomena resulting from the diffractive effects of the multilayered membranes bring about iridescence.

When the capsule is very thin and not overly relucent, its appearance may resemble the glistening structure of the wings of the common housefly (Fig. 452 A) . Slight movements of the beam or of the eye will cause changes in these reflexes indicating their optical origin (mirror zones). In Vogt’s opinion, relaxation of zonular traction by atropine may cause an "ironing-out” of these folds. Graves also showed a similar phenomenon with secondary membranes, in accommodation studies, thus contributing further evidence in support of the Helmholtz theory of accommodation.

The Dark Slitlike Shadow Line {Yogt). One of the peculiar and still unexplained findings occasionally seen in secondary membranes is the so-called dark slit or "rent-like” line. This fine dark line (usually vertical) may be seen running more or less parallel to opaque parts of a membrane or to the border of a group of Elschnig’s spheres. With widening of the angles of illumination and observation, the size of the line may change in shape; when the light is directed from the nasal side instead of the usual temporal direction it can be caused to disappear. According to Vogt, it is not a phenomenon of reflection nor can it be considered to result from a tear or rent in the membrane, because it does not change even under atropinization. If it were a rent or tear, following increased zonular traction, relaxation of the zonule with atropine should cause a change in its


SECONDARY CATARACT 1319

appearance. It may be a shadow line from adjacent structures located at a higher level, caused partly by projection and partly by refraction. Depending on the direction of the beam a shadow effect can be elicited about single vacoules giving the impression of circular holes in the membrane. But alteration between the angle of illumination and observation will reveal that no opening in the membrane exists.

Soemmerrwjg’s King, In 1828 Soemmerrung, commenting on changes in the eye following cataract operation, described the characteristic ringlike after-cataract that now bears his name. Although this structure is seen following extracapsular extractions, it occurs most frequently following needling (in congenital cataracts or in Fukala’s operation for high myopia) or after injury in which the central or axial part of the capsule is opened. If, while the central parts of the lens are being acted upon by the lytic aqueous, the margin of the anterior capsule folds or retracts and becomes adherent to the posterior capsule, all the necessary factors for the formation of Soemmerrung’s rings are present (Fig. 453). Encysted between the layers of capsule there are not only the remnants of lens substance but also regenerated lens material (in the region of the nuclear equator) derived from the capsular epithelium.* Regeneration products play a role in the formation of Soemmerrung’s ring; clinically cases have been observed in which the ring developed some time after discission of a pre-existing secondary membrane. It may happen that after discission, the capsular membranes curl and retract, and with release of internal tension proliferation may begin again. In such cases a large curved sausage- like structure (partial ring) may form. It is hardly likely that after a double exposure coagulated lens material could remain behind to produce such a large formation.

Flistologic preparations usually show that the encapsulated material degenerates and consists of broken-down lens matter and Mor

Histologically it has been demonstrated also that the epithelium (similar to the corneal endothelium [see Volume I, page 424]) may proliferate and not only line the posterior capsule but also may grow around the torn edges of the anterior lens capsule and form a lining of cells on its anterior surface. These cells may secrete new hyaline material and, depending on the number of layers of epithelial cells, may form alternate layers of hyaline membranes. Between these layers varying amounts of lenticular debris and vacuoles may be found.


1320


BIOMICROSCOPy OF THE EYE


gagnian globules. Further degeneration may lead to calcareous and even osseous changes. The picture readily becomes apparent when the central or intervening areas of the membrane are thinned and


Fig. 453. Soemmerrung type of secondary cataract (post-traumatic).


r


darker. The presence of such a formation may be difficult to see biomicroscopically if it is drawn peripherally behind the iris. However, in many cases maximum dilatation of the pupil will reveal it. In others the ring is more centrally located, and it rarely forms a truly complete circle but consists rather of irregularly shaped lentoid masses strung together in a ring or torus form by tenuous processes. With the narrow beam the contents of these structures may be seen to vary from a faintly relucent fluid-like substance (Morgagnian) to an intensely white, crumbly, coagulated mass. Only rarely can actual fibers be made out. Traumatic and spontaneous dislocation of


SECONDARY CATARACT


1321


Soemmerrung’s rings (after zonular degeneration) has been reported, either into the anterior chamber or backward.

Ehchuig’s Spheres (Kngelii ) , Pearls or Bladder Cells. One of the striking and frequently seen new-formations in after-cataract is the clear spheroidal (round or oval) structures first mentioned by Hirschberg (1901)^'^^ and later more fully described by Elschnig (1911).^^^ When massed, they have been compared to clusters of grapes, groups of small soap bubbles, or mounds of frog’s spawn (Plate LXXVII, figs. 5, 6). In one case reported by Cowan and Fry ( 1937) ^ single sphere attained a diameter of 2 mm. The spheroidal

bodies may appear as a flat layer of vacuoles imbedded within the membrane and seeming to interrupt it. Often the small formations may appear somewhat opaque, owing perhaps to changes in the walls or to products within the spheres. In addition, pigment in the form of fine dots or dust may be deposited on their surfaces. The larger clusters of spheres tend generally to develop on one side or the other of the membrane. They may become stationary, may disappear, or eventually may fill and occlude the pupillary opening. Cowan and McDonald (1939)'"’”° estimate their frequency as 25 per cent in cases of secondary cataract. The exact origin and composition of these spheres is still unknown. Elschnig considered them to be "degeneration” products of the epithelial cells and accounted for their spherical shape by the fact that owing to the lack of normal internal lenticular tension the proliferating epithelial cells (see footnote, page 1319) assume a spherical form instead of that of a normal elongated lens fiber (Fig. 454 A, B). Because of the fact that these clusters of spheres in the beginning form in the peripheral parts, Vogt has drawn an analogy between them and the roundish equatorially located coronary opacities.

Although it is commonly accepted that these spheres are of epithelial derivation, it is possible that they may be myelin spheres derived from degenerated lens substance (cf., Cowan and Fry, 1937).^®'’ As mentioned before when a considerable portion of the anterior capsule has been removed and most of the soft lens matter has either been irrigated or removed from the anterior chamber or absorbed



SECONDARY CATARACT


1323


spontaneously, the posterior capsule (invisible with the ophthalmoscope) can be seen early with the biomicroscope, especially by optic section, as a delicate slightly relucent membrane. Not infrequently, even after several years, the patient will complain of fogging vision in such an eye. Biomicroscopic examination will demonstrate that the posterior capsule has become more opaque. In several cases of this kind it was possible to see a delicate vacuolar degeneration in the membrane consisting of a kind of flat layer of spheres but which were smaller than the Elschnig pearls, usually associated with anterior capsular remains. However, the possibility of backward proliferation of the anterior capsular epithelium must be kept in mind.

Crumblike Bodies and Lentoid Forms. As common as Elschnig’s pearls or even more so are the so-called "crumblike” bodies, a kind of lenticular detritus (Plate LXXVII, fig. i ) . These consist of small granular accumulation frequently not larger than good-sized keratic precipitates. These bodies (resorption crumbs) become free and may be found not only on the secondary membrane but also deposited on the posterior corneal surface, on the anterior surface of the iris, and in the vitreous. On the posterior surface of the cornea, such deposits may have a glasslike quality, while on the iris they stand out intensely white and granular. Recently, following an extracapsular cataract extraction two or three of these white dots could be seen with the unaided eye resting on the surface of the iris. Biomicroscopically their granular or crumblike composition and loose attachment to the iris could be established (Thiel and Riedl) .

Cholesterol Crystals. Not infrequently it will be seen that the secondary membrane contains crystals, presumably cholesterol. Cholesterol has the property of crystallizing either in the form of plates of rhombic shape or as needles. These crystals may be found in small localized agglomerations in flat extended layers or as massive accumulations (Plate LXXVII, fig. 4) . Depending on the illumination, they have a polychromatic luster, which is very difficult to reproduce exactly in drawings.



SECONDARY CATARACT


1325


Vigmenfed Secondary Cataract. When pigmentation of an aftercataract is marked and becomes a dominant feature, the resulting structure is known as a "pigmented secondary cataract.” The pig


Fig. 455 {Continued) .

ment may be deposited as amorphous grains or in the form of stars reminiscent of those seen congenitally in the axial region of the anterior capsule on an otherwise intact lens (Fig. 455). The stars may form a veritable net, obscuring the pellicle itself when it is delicate. The color of the pigment may vary from straw yellow to reddish-brown. It is still unknown whether the pigment is freed and deposited at the time of operation or if it migrates over the secondary membrane later. Briichner, who held the latter impression, believed that the pigment is derived from the pigment epithelium of the ciliary body and that it migrates via the zonule to spread on the secondary membrane. The writer has seen a case in which such a possibility was suggested. Through an iris coloboma amorphous pigment ensheathing the zonular fibers was deposited wreathlike on the posterior capsule of the lens. However, since pigment is seen scattered over the anterior lens capsule so frequently (especially after iridectomy in glaucoma) a special origin and method of distribution of the pigment is hardly necessary. Amorphous iris pigment released and dispersed at the time of operative manipulation or soon afterward could be deposited and later assume its ultimate form, i.e., irregularly distributed stars with connecting processes. In this way the pigment actually takes part in the formation of after-cataract.


1326


BIOMICROSCOPY OF THE EYE


Occasionally, owing to iridic adhesions or even to manipulation at the time of operation, detachments of portions of the posterior pigmentary retinal layer of the iris may occur. A flattened darkbrown detached layer may be seen in the pupillary area or sometimes as an apparently structureless sheet curled up on itself. Usually one side remains attached to the posterior surface of the iris.


30 The Zonule

General Considerations

1 ATELY, especially in view of the ever increasing popularity of j the intracapsular method of cataract extraction, interest has been renewed in the morphology and dynamics of the zonular system, a structure that ordinarily does not lend itself to examination in the normal living eye. As in the lens, histologic preparations, because of technical difficulties, have failed to reveal all the details necessary to the complete understanding of zonular morphology. Owing to its delicacy, not only do fixational artefacts occur in histologic preparation but because of the long arcuate course taken by the innumerable fibers making up the zonule, it is not possible, even with serial sections cut at varying angles, to follow a single fiber from beginning to end (Fig. 456). Embryologically, the exact origin and development of the zonule is likewise still unknown. Most modern workers in this field consider that the zonule is of ectodermal origin - derived from the lens, the vitreous (tertiary), or the ciliary epithelium. Duke-Elder states: "The zonula, which is embryologically a specialized region of the vitreous, is secreted in a manner closely similar to this structure: instead of being formed from the retina itself, as is the vitreous, it is formed as an extracellular product of the ciliary epithelium - the prolongation of the retinal elements over the ciliary body.”

Older anatomists (Petit, 1723; Zinn, 1755;“®“ Hanover, 1852), using teased preparations and air injections, believed that the zonule has a membranous structure."' Later histologists, using fixed prep ^ Petit believed that the zonule was formed by a portion being split off from the hyaloid membrane, thus forming a potential space between the posterior zonular membrane and the hyaloid known as "Petit’s canal.” Zinn, whose name this structure commonly bears, described

1327


1328


BIOMICROSCOPY OF THE EYE


arations, held that it consisted of a system of fibers which would permit of free communication with the aqueous fluid of the posterior chamber. With one or two exceptions this idea became ac


Fig. 456. Histologic section of zonule, i. Ciliary body; 2. Lens; 3. Vitreous; 4, Zonular libers.


cepted generally until recently. Although hinted at by Merkel (1870), the suggestion of the presence of a gelatinous cement substance between the fibers (thus reverting back to the original idea of a membrane) was not emphasized until lately.'*' Using fresh eyes with and without fixation, Egger (in collaboration with Vogt) sectioned them through the equator, removing the cornea, iris, and in some of the eyes, the vitreous (up to and including the hyaloid mem this membrane more fully as extending from the lens capsule to the ciliary body. Hanover by injecting air between the anterior and posterior leaves of the zonule demonstrated the presence of a circumlental space or canal (Hanover's canal)

^ DuIce-EIder states: "Embr)'ologically, we could expect the zonule to be of the same essential structure as the sitreous and examination of the fresh eye shows a strong structural resemblance (Beausieux, 1922; Dejean, 1928). Fibers are present but these are probably of the same nature as fibnllae of the vitreous body although more compactly aggregated together, and between them lies a clear, transparent nonstaining gel-like substance, showing the phjsicochemical properties of the vitreous gel."


THE ZONULE


1329


brane) . He was then able to study the fibers of the zonule in situ by means of the biomicroscope. Also by means of scleral windows behind the ciliary body excellent observation could be obtained. A further development of this type of observation was made by Goldsmith ( 1 943 ) Beside his studies of the dynamics of experimental intracapsular extraction, Goldsmith demonstrated many interesting features concerning the morphologic aspects of the suspensory ligament by the injection of dyes and air.

His findings stated, first, that the zonule is seen as a fine transparent pellicle commencing at the posterior border of the orbicularis ciliaris (flat portion) extending forward (covering the inner surface of the ciliary body) as far as the equator of the lens. This membrane consists of a system of small cords seen as fine refractile bands, especially opposite the ciliary elevations. The union of these fibers into small cords is characteristic, and two to three of them are noticed (posterior leaf) for each fissure. A unifying semisolid cement substance enmeshes the small zonular cords and transforms them into a continuous membrane (without perforations) which is extremely thin and delicate except in the portions reenforced by the zonular bundles. The posterior zonular leaf raises itself almost vertically, while the anterior zonular leaf directs itself obliquely upward and posteriorly to meet the posterior leaf at the junction of the posterior and middle thirds of the base of the ciliary processes. This continuous blended layer proceeds posteriorly, where the zonular bundles dissociate themselves into their constituent elements (zonular fibers) at different planes along their path of origin from the entire surface of the orbicularis ciliaris. The zonular fibers arise in their entirety from the complete surface of the orbicularis ciliaris. (This confirms Egger’s opinion, viz., that no zonular fibers originate from the ciliary processes but that all the fibers which go to the lens have their origin further back in the region of orbicularis ciliaris-pars plana [M.L.B.].) Anteriorly the membrane is transparent and affords a good view for study of Hanover’s canal (the space situated between the anterior and posterior zonular membranes) . This space is filled with a viscous substance. The anterior zonular fibers which are condensed into bands do not attain the thickness of the posterior zonular bands. As soon as the anterior zonular bundles reach the ciliary processes they proceed immediately , into the depths of the valleys, without preference for the lateral walls. The anterior zonular leaf is a semipermeable membrane which separates Hanover’s canal from the prezonular space containing aqueous fluid.

Second, the striking anatomic point (posterior aspect) here was the complete independence of the vitreous from the lens on one hand and from the posterior Zonular membrane on the other. The vitreous plays no role in the gross or micro 1 method of examination of preparations with the biomicroscope was also advocated

y roncoso®^^ who holds that the zonule is membranous.


1330


BIOMICROSCOPY OF THE EYE


scopic architecture of the zonular system - the suspensory ligament having nothing to do with the hyaloid membrane. The hyaloid possesses all the characteristics of a membrane, representing the condensation of the most superficial parallel lamellas of the vitreous.

Using fixed preparations, Egger made an exhaustive study of the arrangement and course of the zonular fibers. However, he did not stress the membranous character of the zonule nor the point emphasized by Goldsmith concerning the presence of a cement substance, which seems in the perilental area to make Hanover’s canal a closed-oflf space. Egger did however bring out the fact (first suggested by Vogt) that only by means of specular reflection was it possible to identify the fibers themselves (when viewed from behind) in the region extending from the ciliary process to the orbicularis ciliaris (pars plana) . Only by this method of illumination was it possible to recognize a fiber as it lay in front of the dark brown background. By means of a delicate glass hook it was possible to lift the fibers from the walls and valleys of the ciliary processes and to follow their course. It was seen that two groups of fibers emerged from each valley. The fibers hugged the processes until the ends (or bases) were reached at which point they collected into two or three sagittally-ordered layers to extend to the lens. The groups of fibers on the surface of the ciliary processes were found to go toward the posterior surface of the lens. Those on the side walls, in the angle between the processes and in the valleys were directed toward the anterior surface of the lens. Between these main groups occasional fibers were found going to the equator; but this did not occur in every case (the equator may be completely free of fibers) . In the latter cases all the anteriorly directed fibers were found to insert on the anterior lens surface. Here and there circular branches were seen extending between the ciliary processes. It was found that the fibers do not end at the peripheral ridges or in the valleys but that a majority almost reach the ora serrata, and that the separation of the zonule into single bundles is caused by the ciliary processes. According to measurements under high power the average length

On the average there are about 68 cillzry processes, the distance between them being 0.7 mm.


THE ZONULE


1331


of the fibers is from 6 to 6.5 mm. When lifting a bundle with the glass hook it was seen that numerous fibers branched singly to change their direction. In the region of the pars plica, the crossing of the radial fibers occasionally may occur. This happens when fibers which go to the anterior surface of the lens and which run over a plica (plicae ciliaris) seem to be crossed by a fiber coming from the depths of a valley which goes to the equator or posterior lens surface.

linertion of Zonule on the Lem. From the observations of Egger and Vogt it is possible to establish that three principal insertional areas on the lens capsule can be differentiated: (i) anterior zone; (2) equatorial zone; (3) posterior zone (Fig. 456).

The anterior insertional zone according to the measurements of Egger and Vogt extends further toward the axial region (from the equator) than the posterior zone. Anteriorly this distance was o.j mm. and posteriorly from o.i to 0.2 mm. The fibrilla closest to the capsule could only be recognized in dry preparations. The course of the fibers on the lens had to be diflferentiated from the fine radial lines of the peripheral lens fibers whose course was almost parallel. The zonular fibers at their capsular insertions are angulated acutely as they leave the anterior and posterior lens surfaces. The divergent equatorial fibers when present pass into the circumlental space and insert irregularly at the equator as separate fibrillae. With the optic section, inspection of the circumlental area revealed two principal zones of zonular fibers (anterior and posterior) which are separated by a space (Hanover’s canal) relatively poor in equatorial fibers. The width of this space in the vicinity of the fixed lens is 0.5 to 0.6 mm. Near the tips (bases) of the ciliary processes it is not more than 0.16 mm., while over the processes themselves the fibers coalesce and lie directly on the epithelium. As the fibers abut the capsular surface they form brushlike filaments, the capsular expansions of which develop a delicate membrane (the zonular lamella) (Plate LXXVIII, fig. I ) . This membrane may be formed by the same cement substance that has been shown to exist between the fibers in the perilental space. The zonular lamella occupies the equatorial and periequatorial regions of the lens capsule (an area measuring


1332


BIOMICROSCOPY OF THE EYE


from 1.5 to 2 mm.) and hence as previously mentioned must not be confused with the more axial part that separates in senile exfoliation of the superficial capsular lamella, in glaucoma capsulare and in heat cataract. Considerable evidence, both histologic and biomicroscopic has been advanced to confirm the idea that a zonular lamella actually exists (see Plate LXXVIII, fig. 2; also Figs. 465, 466). Using special technics, its presence has been verified by Berger, Retzius and Busacca and Komai."' Clinically with the biomicroscope, Meesmann (1925) first described the appearance of a zonular lamella detached from the true capsule in a case of trauma.*'^" The detached zonular lamella appeared as a circular membrane around the equator. Although normally the equatorial margin of the lens appears as a smooth regular surface actually during accommodation it is somewhat undulating (physiologic undulations or crenations) .f Pathologically accentuations of these undulations can be seen biomicroscopically through a coloboma or when the lens is displaced in places where the (anterior) zonule is missing or torn away. This would suggest that the physiologic irregularities of the lens margin are related to the action of the zonule.

Other cases illustrating the existence and separation of the zonular lamella were reported by Vogt (192 j) Stein (1926) and Kronfeld.'^^'’ Stein demonstrated a case of chalcosis in which the zonular lamella and the zonule itself was stained with a green deposit of copper. Vogt reported 2 cases (4 eyes) of detachment of the zonular

Berger bj' means of maceration found that an independent lamella (zonular) could be identified in the region of the equator. With this method he was able to separate the lamella with zonular fibers attached to it. Both von Ebner'*^® and Elschnig"*^® presented histologic sections showing detachment of the zonular lamella. In detachment of the zonular lamella tlie axial region of the capsule is never affected as in senile exfoliation and in glassblowers cataract. Also in the latter conditions subluxation or luxation of the lens does not ordinarily occur. Consequently the term detachment of the zonular lamella should not be used to describe these ts\'0 conditions.

t The number of these undulations or crenations which run antero-posteriorly at the equatorial edge of the lens has been estimated as about 40, corresponding to the number of ciliar}’ valleys. Hess (1S96) and later Brown (1928) showed that these indentations became more prominent after atropinization contrariwise less marked after the use of eserine. Brown demonstrated the same phenomenon in an eye (with optical iridectomy) biomicroscopically. Employing internal reflection from the contained nuclear cataract he was able to visualize the equator. While causing the patient to accommodate by fixing a near object, he saw an accentuation of the crenations and vice versa he noticed that they became less marked when a distant object was fixated.


THE ZONULE


1333


lamella associated with bilateral spontaneous luxation of the lens.

After intracapsular cataract operation inspection reveals no zonular fibers attached to the extracted lens, perhaps the pressure exerted by the hook during the operation tears the zonular lamellae from the lens capsule rather than the fibers from the zonular lamella. However, according to biomicroscopic findings in cases of spherophakia and ectopia separation of the zonular lamella does not occur in every case. This is deduced by the frequency of the presence of torn fibers and their remnants adherent to the capsule, possibly indicating in these cases a higher degree of fragility of the zonular fibers themselves. ' '


SITE OF ORIGIN OF THE ZONULAR FIBERS

Although it is generally agreed that most of the zonular fibers arise from the ciliary epithelium of the orbiculus ciliaris the exact way in which this occurs is still undecided (Fig. 457) . V. Lenhossek ( 19 1 1 ) , in contrast suggested that their primary site of origin might be the lens, and that their ciliary attachment could be secondary. Mawas (1910),^’ Magitot (1912),^^" Dejean (1925),^'^' and others considered the zonular fibers of epithelal origin, arising either from the cells themselves" or between them. Terrien (1898)”"’’’®^” and Wolfrum (1908) held that the fibers came from between the cells originating from the underlying Bruch’s membrane, or from cells corresponding to Muller’s fibers (supportive tissue of the retina) . Salzmann (1900) considered them to be derived from the internal limiting layer. The intimate relationship between the zonule and the internal limiting membrane (of the epithelium of the para caeca) is well demonstrated in histologic preparations. The last two conceptions would identify the zonular fibers as being of a glial nature since both the internal limiting layer and Muller’s fibers are modified forms of this type of cell. If the zonule was derived from

Lhy epithelial cells could produce such long processes (up to 7 mm.) is not beyond possibiht)' because, analogously, fibers of considerable length may be produced by the capsular epithelium of the lens and the fibers of the dilator iridis, from the posterior epithelium of the iris.


1334


BIOMICROSCOPY OF THE EYE


Bruch’s membrane, it is conceivable that together with the lens capsule it is part of the glass membrane system.

In summation, it must be admitted that at present very little is

/


Fig. 457. Histologic section showing passage of zonular fibers between ciliary processes from the lens to the site of attachment at the flat portion of the ciliary body. (After Jess.)

known concerning the development, origin or insertion, physical (elasticity or extensibility) or chemical characteristics of the zonule. Likewise, as pointed out by Vogt, we know hardly anything about individual or senile variations and it would be of highest theoretical and practical interest to fill these gaps in our knowledge in view of the zonule’s importance in accommodation and also in surgery.

TECHNIQUE FOR EXAMINATION OF THE ZONULE

In examining cases in which the zonule is sufficiently exposed so as to be accessible to the beam of the biomicroscope,’'’ high intensity of illumination and magnification is required. The use of at least


It is only in the presence of iris colobomas (of congenital, traumatic [ruptures and dialyses], and surgical origin) or lens displacements (subluxations and luxations) that the edge of the lens and the zonula becomes sufficiently exposed to permit adequate biomicroscopic examination. However, in the verj' young, when the pupil is maxhnall) dilated (e.g., using adrenalin or 10 per cent neosynepherin, the insertion zone of the anterior zonula fibers to the (normally placed) lens may just be visible. With the exception of the directly traumatic cases, lens displacements may be hereditarj' or congenital or may arise spontaneously usually secondarily to high grade congenital myopia, hydrophthalmos, inflammations (iridoq-clitis or meitis) and cataract (p.articularly in shrunken lenses).


1335


THE ZONULE

40 X magnification is desirable. As is the case of the contents of the anterior chamber and the vitreous where the delicate structures (invisible by diffuse illumination) can only become visible by means


Fig. 458. Examination of the zonular fibers by means of specular reflection. Note shagreen of the anterior capsule. Posterior zonular fibers are seen faintly behind the stronger and better developed anterior ones.

of the tyndall phenomenon, all examinations of the zonule must be performed by direct focal illumination. Similarly, appearances and visibility may alter with the direction of the light. Therefore when examining the zonule the beam should be directed first from the temporal side and then from the nasal. Preferably the examination room should be dark and the examiner at least partially darkadapted. When feasible the pupil should be dilated. Both the wide beam and optic section should be employed. Since the intensity of illumination is decreased with the narrow beam, overloading the light source will give added brightness. By means of specular reflection it is often possible to render visible zonular fibers which may be hardly recognizable in ordinary direct focal light (Fig..458). Slight


1337


THE ZONULE

(but slow) oscillatory movements of the beam are frequently of great help in accentuating visibility. This will be understandable when one considers that the zonular fibers are prismatic in shape rather than round and hence their reflection (and visibility) will vary with the direction of the light. On the other hand although the visibility of the fibers themselves become enhanced by specular reflection, those located deeper may be obscured in the reflex of the more anterior and hence details concerning the deeper ones (although not brilliant) will be seen better in the beam outside the mirror zones. Even in the most favorable cases only that part of the zonule which extends from the lens to the tips of the ciliary processes will be seen. In directing the beam obliquely the margin (equator) of the lens becomes highly dispersive, appearing as a white line (see Fig. 459). The fibers going to the anterior lens capsule will be seen passing anterior to this line to their point of insertion. In addition, when the lens is displaced (as in ectopia), passage of the beam through it at some distance from the subluxated edge will cause this edge (equator) to glow as a reddish line. This is the result of internal reflection, a form of "lens scatter.” The fibers themselves appear as delicate threads that glisten when viewed by specular reflection. They have a tendency to form groups and bundles; this is not surprising since, as already indicated, the fibers coming from the valleys- are necessarily collected in bundles because of the ciliary processes.

The beginner is often astonished to find how far forward (axial to the equator) the fibers are really inserted. Posteriorly the fibers insert closer to the equator. Anteriorly as well as posteriorly many of the fibers are collected in bundles. In most instances in which it becomes possible to see the fibers, it is rare indeed to find them entirely intact. In certain areas the bundles may be found to be spread apart or missing (Fig. 462; Plate LXXVIII, figs. 2, 5, 6). As a rule those that we do see are stretched out. Frequently remnants of torn fibers will be seen curled up at their attachment to the capsule. In others all that remains at the site of the capsular detachment and the fibers are small white dots (Plate LXXVIII, fig. i ) . In prac


135S


BIOMICROSCOPY OF THE EYE


tically all of the cases in which the fibers can be seen (since some abnormality or pathologic process has made this possible) they are already changed. The changes consist of deposits of white and brown (pigment) dots between or on the fibers (Plate LXXVIII, figs. i-6) . Often when they are profuse, such deposits may form a sheathing about the the fibers for varying distances. Such changes probably precede fragility and enhance the visibility of the fibers. Erggelet was the first to describe these alterations. In one case, after iridocyclitis, it appeared as if the fibers were covered with dust. Meesmann considered increased opacification, swelling, and deposits as signs of degeneration of the fibers, Comberg (cited by Vogt) described deposits of white and red blood corpuscles on the fibers as well as fibrinous agglutination of the fibers themselves.

As previously mentioned, there is still a great paucity of knowledge concerning the tensile strength and elasticity of the zonular fibers. That these fibers can undergo considerable stretching without being entirely torn off is apparent in cases of subluxation and even of total luxation. Often when the lens is completely luxated into the anterior chamber, it is still possible to see stretched or broken zonular fibers attached to it. That the fibers can stretch for several millimeters and remain so for long periods before rupturing is evidenced in cases of pathologically shrunken lenses. Whether or not it is possible for detachment of the ciliary epithelium or the layer below it (Bruch’s membrane) to occur in the region of the orbiculus ciliaris is not certain. It is more likely that in an acute (e.g., trauma) or chronic overstretching (spontaneous luxation) that the zonule is torn from its lens attachment rather than from its point of origin. As Vogt has pointed out, some authors have believed that in cases of congenital ectasia, spherophakia, and microphakia the fault lay in abnormally long fibers, genetically determined. He doubted this hypothesis because in all his cases in which anomalies and long fibers occurred, torn or broken fibers with pigmented or whitish deposits were found. These abnormalities do not result from otherwise normal congenitally long fibers but rather from an inherent inferiority or weakness of the fibers themselves. In other words, in


THE ZONULE


1339


these conditions it seems that we are dealing with a rudimentaryzonule which undergoes degeneration owing to a faulty or defective anlage which is conducive to stretching and tearing of the fibers.

The Zonule in Certain Hereditary and Congenital Anomalies

In certain ocular defects, the zonule or parts of it may be accessible to biomicroscopic inspection; the zonule in congenital coloboma of the iris and lens and in ectopia lentis, in spherophakia, and in microphakia is therefore considered in this section. Some writers consider that all these conditions are related in so far as they result from varying degrees of zonular fiber destruction. That is, with partial involvement ectopia will result and that when all the fibers are stretched (loose or torn) or aplastic, microphakia or spherophakia may be induced. Microphakic (congenitally small) lenses are always ball-shaped or spherical. Therefore the difference, if any, between the terms microphakia and spherophakia can only reside in the size of the lens. If it is true (as seems likely) that all these anomalies are the result of a hereditary defect in the anlage of the zonule then we might consider that ectopia, spherophakia, and microphakia simply represent successive degrees of deterioration. In microphakia and spherophakia, the lens is in a perpetual state of complete accommodation; being rounded, it approaches in shape that of the fetus or newborn and resembles the lens of young children in the state of total accommodation. Thus it will be found that considerable lenticular myopia is present even when corneal curvature and axial length of the eyeball are normal.

THE ZONULE IN CONGENITAL COLOBOMA OF IRIS AND LENS

In colobomas of the iris the edge (equator) of the lens will lie behind the pillars and run at right angles to them. The edge of the lens may be straight, crenated or slightly undulating (Plate XL VI,

” Besides the hypothesis of congenitally long fibers for the causation of microphakia (Saeger and H. Meyer) Marchesani has suggested that the weakness of the zonule may result from a hyperplasia of the ciliary body. In addition to a defective zonule Gnad considered the possibility of an abnormally small lens anlage.


1340


BIOMICROSCOPy OF THE EYE


fig. 6) . If one angulates the eye or the beam so that the mirror reflex approaches the lens' equator the bundles of zonular fibers will readily become apparent. Using the optic section and high power, 40 X or more, and by alternate changes in the direction of illumination with corresponding changes in the focus of the microscope, one will be able to distinguish between the anterior and posterior bundles of the zonular fibers (Fig. 458) . It will be seen in many cases that some of the anterior fibers are wholly or partially missing or torn. In the latter case remnants of torn fibers will appear as white dots on the lens capsule or as short curly threads adhering to it. These may be found as far as one-half the distance between the equator and the axial region of the lens. Ordinarily the posterior fibers are not inserted as close to the axis as the anterior. Being shorter, the posterior fibers are straighter, and unless the lens is subluxated they are less liable to be torn. Small white points or pigment granules may be found to be deposited on or between the fibers, particularly when cataract is present or when the lens is displaced (Plate LXXVIII, fig. 6). In those cases in which there is considerable tearing or in which the anterior zonular fibers are missing, the anterior surface of the lens may be more curved than is normal."'* Probably from the same cause, the degree of peripheral divergence of the anterior zones of discontinuity may be less than that of the posterior. When larger openings in the anterior zonular bundle are associated with similar defects in the fibers directed to the posterior capsule, a forward herniation of the vitreous may occur. In such instances the surface of the herniated vitreous may be accented by deposited pigment cells. The association of ectopia lends with iris colobomas is well known. Retractions of the lens margins may be considered as colobomas of the lens. Such an effect can also be produced by a contusion; following tearing of the zonule a localized retraction and rounding of the equator may occur (capsule remaining intact) (Fig. 464 ) . Likewise, undulations of this t5'^pe may be seen in cases of shrunken lenses (which are usually somewhat luxated or ectopic) especially after an

This again emphasizes the importance of the anterior zonular fibers in the process of accommodation since it is chiefly’ in anterior parts of the lens that relaxation occurs.


Tl-^E ZONULE


1341


iridectomy lias been performed in the region of the ectopia (Fig. 463). When these localized undulations of the lens margins are marked, they may resemble "pseudopodia” (Vogt). In studying the zonular attachments in these instances it will be seen that the anterior zonular fibers are found only in the region of the pseudopodia and not in the retracted areas between them. Probably, this is an indication that the stronger anterior fibers attached to these processes contributed to their formation owing to the lack of traction in the retracted areas. Evidently, in the absence of zonular traction the lens margin (equator) retracts and becomes more rounded sagittally. It is interesting to observe that the posterior zonular fibers may still be present even in areas of retraction between the "pseudopodia.”

HEREDITARY SPHEROPHAKIA ("BALE-SH APED LENS,”

LENS ROTUNDA AND MICROPHAKIa)

In microphakia (congenital smallness of the lens) the lens itself is always round or spherical (spherophakia) (Fig. 459). The equatorial diameter is thereby reduced. In one of Vogt’s cases it was 7.5 mm., a figure corresponding to that given for microphakic lenses by Fleischer and Saeger. Mayer and Holstein found more than 20 cases of microphakia reported in the literature. In only one of these was the condition limited to one eye. In several it was found in siblings of consanguinous parents, and hence it is probably transmitted as a recessive character.'"' Vogt has estimated that in his cases the sagittal thickness of the lens was one-quarter greater than in the normal lens. This accounts for the high degree of lenticular myopia even when the corneal curvature and axial length of the eye are normal. This was verified by the fact that in one case, before lens extraction there was a myopia of 12 diopters, while after lens extraction in the same eye a hyperopia of 12 diopters was found. In microphakia or spherophakia the peripheral divergence of the zones

In all the hereditary diseases of the eye there is perhaps not one degenerative change that cannot first appear in later life (abiotrophy) as well as congenitally. This may occur in the zonule (Vogt) in a way similar to senile degenerations of the lens and retina, and may account for the fragility of the zonules (as seen surgically in intracapsular cataract operations) even as a presenile manifestation, as well as in old age.



THU ZONULE


1343


of discontinuity is diminished to a high degree, thus suggesting that this phenomenon is related to zonular traction. As discussed in the chapter on the normal anatomy of the lens (pages 1016-1017),


('

Fig. 460. (.Contniuid) C Fctopi.i Icntis Note .ilistncc of /oiuil.ir fibers cKCcptm,!’ for .i few above and torn remn.inls on .interior c.ipsule; .ilso reflex line from the posterior capsule

zonular traction plays a I'olc in the formation and development of the suture system - which in turn permits dorsoventral flattening of the lens. Normally and especially after the adult nucleus is well delineated, it will be seen that equatorially its surfaces angulate acutely (page 998). This may also result from zonular traction since in spherophakia, in which zonular traction is missing, the equator of the nucleus is circular.

As already indicated the finding of torn or absent zonular fibers, with or without pigment deposits, strengthened the concept that microphakia, spherophakia, and ectopia result from a congenital weakness or aplasia of these fibers. This would tend to refute the view generally held that these conditions result primarily from a congenital abnormal lengthening of otherwise normal fibers, which with consequent lessened traction permit the lens to maintain its fetal form.


1344


BIOMICROSCOPY OF THE EYE


When the anlage of the zonule is completely defective, varying degrees of microphakia result. When the defect is localized to one zone, ectopia follows. In other words, these anomalies may arise from an inherited weak zonule, the lens itself only being secondarily affected.

Owing to unequal traction of the remaining pathologic fibers, the small, round or spherical lens may be ectopic; or if it is supported within the pupillary area, it may prolapse somewhat into the anterior chamber. As a result, the anterior chamber may be very shallow, especially axially. The surface of the lens in this case more or less parallels the curve of the cornea. When the lens does not protrude into the pupil, the depth of the anterior chamber may be increased. Herniations of the vitreous are not uncommon. If the lens protrudes forward into the pupil, the use of miotics may further accentuate the ball valve action and may cause a rise in intra-ocular pressure. Conversely, mydriasis may cause a reduction of the pressure. Complete luxation of the lens into the anterior chamber with secondary glaucoma is a complication common to this condition and to ectopia lentis as well. This may also occur when the lens is shrunken (Fig. 460 A) . Notwithstanding their congenital nature, luxations may be brought about by progressive zonular deterioration abetted mechanically by sudden strain incident to external trauma, or even after coughing, sneezing, or exercise. Although these conditions (microphakia, spherophakia, and ectopia lentis) are congenital, they may not remain stationary. Progression of zonular deterioration may lead to further lenticular displacement. Owing to the poor vision, many of these eyes develop varying degrees of nystagmus. Iridodonesis as well as phakodonesis is present.

Biomicroscopic examination in these cases should be done with the pupil dilated, if possible. As the beam is passed through the lens, a linear reflex may be seen derived from the posterior capsule. The reflex becomes longer and more distinct as the equator is approached (Fig. 460 C) . Parallactically the reflex moves in a direction opposite to that of the beam. The condition of the zonular fibers themselves will vary from case to case. They may be entirel}'- absent (rare) or


THE ZONULE


1345


the bundles may be, as is more likely, missing in certain areas. When present they show varying degrees of pathologic change and are seen best by specular reflection. Usually their insertion is more peripheral than in the normal eye. Curled remnants of torn fibers may be found attached to the lens, or as small white dots at the site of their former attachments peripherally on the anterior capsule. Characteristically the fibers present are delicate, loose and wavy as compared to normal ones. In many cases pigmented or whitish deposits will be found deposited on the fibers or between them. In places, these deposits may be so thick as to form a coating similar to the insulation on a wire. (See Plate LXXVIII, figs. 3, 4, 6.)

HEREDITARY AND CONGENITAL ECTOPIA LENTIS

Hereditary and congenital displacement or subluxation of the lens must be differentiated from the luxations following trauma and those appearing spontaneously subsequent to intra-ocular disease. In all, the displacement of the lens results from a damaged zonular apparatus. Hence from a purely biomicroscopic viewpoint (not considering the history and damage to the neighboring structures which usually occurs in trauma) the appearance of traumatic ectopia lends does not differ markedly in itself from that seen in spontaneous hereditary displacements (lens sizes being equal). However, in hereditary and congenital ectopia, the condition is practically always bilateral and symmetrical, the displacement being predominantly upward or upward and outward, and is found in successive generations, transmitted usually as a recessive character although it may be dominant (Waardenburg) . It may occur alone (simple form) unaccompanied by any other anomaly (ocular or otherwise) ; it may also occur with other ocular defects (iris coloboma, pupillary membranes or lens opacities) in the absence of systemic defects, or it may be part of a syndrome, in which it is associated with widely disseminated abnormalities of the bones and muscles, especially of the extremities, e.g., Marfan’s syndrome (arachnodactyly and distrophia adiposa congenita). In ectopia lentis the partially displaced


1346


BIOMICROSCOPY OF THE EYE


lens may be stationary or it may become completely luxated, gradually or suddenly. When the increase in displacement is gradual, progressive destruction of the zonule may be suspected; if it is sudden, trauma (even when indirect, e.g., sneezing or bending) must be considered as a possibility. As already noted, the complication of luxation of the lens into the anterior chamber leads not only to secondary glaucoma but also to opacification of the cornea, provided the lens remains in contact with it.

Excepting for the hereditary nature of this form of ectopia very little is known about its exact pathogenesis and consequently numerous theories have been advanced to explain it."' However, owing to the fact that in no case examined biomicroscopically have perfectly normal fibers been found (Vogt) it would seem that the most probable explanation lies in a defective anlage of the zonule. When this is complete or nearly so, spherophakia results with partial ectopia. As is the case with many other hereditary degenerations, the effects are not manifest at birth but may appear later or even as a presenile alteration (abiotrophy). Hence it is not surprising that this condition, besides being congenital, can suddenly appear at any time after birth and like other abiotrophic degenerations (presenile or senile macular degeneration or even senile cataract and graying of the hair) may be progressive. The most frequent complication in ectopia is complete luxation and its attendant sequelae (prolapse of the lens into the anterior chamber followed by iridocyclitis, keratitis and secondary glaucoma) . Posterior displacement of the lens into the vitreous ma) not be accompanied by untoward complications or increased intra-ocular pressure. Vogt (1905 and 1925) reported a pedigree extending over 100 years where without any known cause (abiotrophy ?) 16 out of 46 descendants were affected. Between the

" Among these are: that like lens colobomas, ectopia may result from the persistence of embr)-onal vessels (Hess, 1911; Rones, 1934 and others); abnormality in closure of the fetal cleft interfering with development of the zonule; high grade myopia causing a disproportion between the size of the lens and the space allowed for it could result in stretching and tearing of the zonule; eccentric location of the developing lens; abnormally long but otherwise normal zonular fibers; also because of the occasional finding of pupillarj' membranes and strands, (some of which come forvs'ard from behind the pupil and lie on the anterior surface of the lens border) it is thought that traction may be exerted. (Fig. 151b)


THE ZONULE


1347


ages of 20 and 70 years these persons, whose eyes previously were normal, began to have trouble with their vision. The lens began to slip down, and the visible zonule above was seen to be extended.


Tig. 461. Hereditary ectripia lentih. a. Detachment of the zonular lamella. (After Vogt.)

H. Complete separation of the zonular l.imella anteriorally from the capsule. (After Vogt.)

fragile and torn. Especially interesting was the fact that separation of the zonular lamella occurred in some instances (Fig. 461 A, B). Eventually many of these patients developed glaucoma, some with and others without total luxation.

According to the conception of an inherited weak zonule the changes in the lens itself in spherophakia and ectopia are secondary. Pathologically many observers (Seef elder, Fuchs, Reese and Clark) have noted the presence of poorly developed and retracted ciliary processes. The significance of this in ectopia is not completely understood but most likely it is secondary to imperfect zonular development.

From the standpoint of biomicroscopy the findings in ectopia will vary somewhat with the degree of lenticular displacement. The lens may be displaced so far that its edge cannot be seen in the undilated pupillary area (complete aphakia). In this case, passage of the beam will reveal the undulating surface of vitreous body /;/ sHu behind the pupil. Occasionally herniations of vitreous anteriorly may occur. In


1348


BIOMICROSCOPY OF THE EYE


such instances of marked displacement it is rare to find many zonular fibers in the area of the small pupil. Iridodenesis is usually present. The vitreous generally shows changes in its trabecular structure and also may contain deposits. 'With dilatation of the pupil - always diflScult to obtain in ectopia - the margin of the lens may come into view."' However, in this type of case, unless the ectopia is associated with iris coloboma (a not too infrequent combination), it is often impossible with the biomicroscope to see the margin of the lens (when displaced inferiorly) , because the rigidity of the apparatus does not permit sufficient angulation of the beam. When this is so, it is necessary to resort to the ophthalmoscope, which usually will reveal the edge of lens as a dark rim across the red fundal reflex. When the lens is not overly displaced, passage of the focal beam will readily reveal its presence and its margin. If the beam is directed so that it passes partly through the lens and partly into the aphakic part of the pupil, an abrupt and sharp contrast will be seen between the pearly gray relucence of the lens and the dark aphakic portion. Opacification of the lens will enhance the contrast. By means of internal dispersion, light from the beam (a kind of scatter) causes the margin of the displaced lens to glow as a bright reflex. As in spherophakia the zonular fiber bundles in the area of the defect may be totally .or partially missing. The fibers may be stretched or torn, in which case remnants and rests may be found at the site of their former attachment. But in certain cases exaggerated branching of the fibers (to form brushlike endings at the lens) may be very marked. The fibers begin to branch and diverge at a greater distance from the lens than is normal. Pigment and whitish deposits are commonly seen on or between the fibers. There may be a definite decrease in peripheral divergence of the zones of discontinuity and a rounding of the equator of the adult nucleus (Fig. 459). With luxation of the lens into the anterior chamber, the edge of the lens may be seen to ride over the pupillary margin. This may cause the formation of a concentric shadow line on the iris near the pupillary margin when the beam is

The difficulty in obtaining mydriasis in all forms of ectopia is well known. In a case of Marfan’s syndrome, Theobald found histologically that the dilator iridis was not developed.


TMU ZONULE


1349


directed over the lens margin (Vogt). Usually only delicate and retracted remnants of the '/onule (attached to the lens) will be seen. Detachment of the zonular lamella of the lens capsule may occur in hereditary ectopia and spherophakia as well as following trauma. The separation is usually irregular and may be restricted to one or more zones. It appears as a delicate membrane separated from the underlying equatorial capsule by a lucid interval (Fig. 461 A). Depending on the traction of the remaining zonular fibers, its surface may be smooth or undulating. Since the anterior fibers of the zonule are the strongsi, the zonular lamella may be torn from the anterior capsule, and its free edge may be folded forward. This is exemplified by the frequency with which the anterior zonular fibers remain attached to the separated lamella (Fig. 461 B). These fibers are seen to be loosened and wavy. Posteriorly, although it is separated up to its pre-equatorial extremity, the lamella does not so readily tear away entirely from the capsule. This could indicate that the weaker equatorial and posterior zonular fibers tear off more easily from the lamella than does the latter from the capsule. The attachment of the lamella to the capsule thus appears to be stronger posteriorly.

The association of ectopia leniis with generalized abnormality of the musculature and bones (arachnodactyly) in Marfan’s syndrome is an example of a hereditary condition in which generalized mesodermal and ectodermal defects arc associated, e.g., the dilator pupillae and zonule (nowadays the zonule is regarded as being of ectodermal origin). Evidently such a combination illustrates the genetic phenomenon of crossing over and then the coupling of


According to Weve about -to per cent of those having arachnodactyly have ectopia lentis. The extraocular findings in Marfan’s syndrome which have been noted (not all being found in any single case) by numerous authors and cited by Weve, Vogt and Rados are: abnormal thinness of the extremities, the elongated phalanges (spider fingers) and contractures of their joints (hence the name "arachnodactyly"), small chest, winged scapulae, spinal curvatures, high arched palate, deep seated eyes, contraction of articulations, spur of calcaneous, duck-foot, flat feet, long and thin face (dolichocephalic), double row of teeth, enlargement of sella turcica, valvular heart dise.ase, patent foramen ovale, large ear lobes, reduced number in the lobes of lung, abnormally long intestine. In the eye, in addition to ectopia lentis and spherophakia, there may be incomplete development of the iris stroma and owing to defects in the sphincter iridis and especially in the dilator iridis (both of ectodermal origin) dilatation of the pupil may be accomplished with difficulty.


1350


BIOMICROSCOPY OF THE EYE


single characters or defective hereditary qualities regularly within a single chromosome. In this way characters which somatically are far apart may be closely linked.

The frequent association of ocular anomalies and those of the extremities is well known. Recently I reported two cases in which pupillary membranes were associated with syndactyly. According to Sorsby the fact that in the segmented animal the eye and tentacles are homalogous, being the sense organs of different segments, may have some significance in this connection. There is now evidence to support the view that the inheritance of Marfan’s syndrome may have a recessive as well as a dominant character. As in simple spherophakia and ectopia, monocular as well as binocular, spontaneous total luxation of the lens may occur either into the anterior chamber or vitreous. This has raised the question as to whether Marfan’s disease is progressive. Progression in the strict sense as seen in dystrophies may in hereditary conditions only be a manifestation as Bellows states of "increased susceptibility to injury and inflammation.”

Biomicroscopically, except for the possibility of detecting defects in the stroma of the iris, our interest lies in the accompanying ectopia lends. Since this differs in no way morphologically from simple ectopia just discussed, no further description is necessary. However, those who are interested in a more complete survey and discussion of this syndrome are referred to the excellent papers by Weve and Rados.

Pathologic Alterations of the Zonule Following Inflammation

Alterations in the zonule after inflammation, i.e., iridocyclitis, may be observed biomicroscopically in the presence of coloboma of

In addition to the combination of ectopia-myopia-heart disease (Strebel -Steiger), Vogt lists several combinations or complexes as examples of the genetic phenomenon of crossing over and coupling of characters so that in the end they become linked inside a single chromosome - and later appear as well defined syndromes. Among these are retinitis pigmentosa and deafness; axial myopia with large interpupillary distance (large skull base); axial hyperopia with small interpupillary distance; aniridia with aplasia of the macula, sexlinked recessive aplasia of the macula with corneal astigmatism; corneal astigmatism with albinism; syndrome of blue scleras, deafness and fragility of the bones; there is also statistical evidence to prove the frequenq’ of hyperopia in morons and myopia in intellectuals.


1351


THE ZONULE

the iris (either of congenital, operative or traumatic origin) or when shrinkage of the lens permits inspection. Not unlike the findings in hereditary alterations, the zonule shows varying degrees of destruction. The fibers may be torn or absent in places. Those that are seen, depending on the degree of traction, are frequently stretched and taut. Others may be coiled, and torn remnants may be seen attached to the lens. In some cases because of increased reflection of the anterior layer of fibers, repeated changes in the direction of illumination will be necessary to bring out the lesions in the deeper fiber bundles. Specular reflexes which enhance the visibility of the superficial fibers may conceal torn and coiled fibers behind them. When all the fibers are missing in a certain sector, irregularities or notching (coloboma) of the corresponding segment of the lens margin may be seen (page 1341). This is more likely to occur when the lens is cataractous and shrunken.

A very pronounced characteristic change after inflammation is the sheathing of the fibers by pigmented and whitish deposits (Plate LXXVIII, figs. I, 3, 4, 5). This sheathing may be continuous or interrupted and causes the fibers to stand out in bold relief. In cases of old iridocyclitis, heavily pigmented fibers appear like miniature brown cords of rock candy. These changes are symptoms of zonular destruction and explain the ease - well known to surgeons - with which complicated cataract (so often a sequelae of chronic iridocyclitis) can be extracted intracapsularly. After freeing any iridic adhesions, only slight pressure is required to break the fragile zonular fibers. This also holds true for shrunken cataractous lenses resulting from inflammation, trauma, or hypermaturity (senile cataract) (Figs. 462 and 463). In the latter instance, complications such as iritis and secondary glaucoma are not uncommon (page 1139). The high degree of fragility of the zonule explains the spontaneous luxation that may occur in cases of cataracta complicata and shrunken lens. Phakodonesis as well as iridodonesis usually are demonstrable.

In addition, in cases of shrunken lenses in iridocyclitis with operative colobomas, Vogt has described the parallel striping seen by specular reflection on the anterior surface of the vitreous (Fig. 4^4) .


PLATE LXXVIII


Fig. I. Subluxated lens. Chronic glaucoma. Almost total iridectomy. Remains of iris attached to the posterior corneal surface. Note that the zonular fibers pass through the circumlental area and extend between the tips of the ciliary processes.

Fig. 2. Shrunken cataractous lens. Iridectomy above. Sparse zonular fibers seen attached to the lens. Questionable separation of the zonular lamella.

Fig. 3. Shrunken cataractous lens. After iridocyclitis. Iridectomy, Note pigment deposits on the zonular fibers. (After Duverger and Velter.)

Fig. 4. Subluxated lens. Shrunken and cataractous. Chronic iridocyclitis. Note pigment deposits on the zonular fibers and on the posterior lens capsule at their attachment.

Fig. j. Subluxated cataractous lens after iridocyclitis. Zonular fibers are sparse in number. Some of them show fine deposits.

Fig, 6 . Aniridia. Subluxated lens. White deposits on zonular fibers. Lamella type of lens opacity.


1352



Fig. 462. Shrunken lens with stretched annular fibers. Deposits on zonular fibers. Some of the

fibers are missing.


Fig. 463. Shrunken lens. (After Vogt.)


1355


1356


BIOMICROSCOPy OF THE EYE


This striping has the character of zonular fibrillation. That their location is identical with that of the anterior hyaloid of the vitreous is demonstrated by the fact that these lines oscillate with it. They are seen in places devoid of zonular fibers and run either in the usual radial direction of the zonular fibers or at times concentric to the lens margin. The lines do not connect with the lens but seem to pass behind its edge. The nature and significance of these lines are not understood. Perhaps they represent adherent zonular fibers or possibly congenital rests. It is more difficult to explain those that run circularly or at right angles to the usual course of the zonular fibers excepting that they are reminiscent of the disputed occasional circular fibers connecting the ciliary processes (Eggers). In addition, particularly when the displaced or shrunken lens is opaque, its margin often casts a shadow on the surface of the vitreous adjacent to it. The width of this projected shadow increases as the angle of illumination is made more obtuse. Likewise the location of the shadow will wander with changes of the direction of the light.

Traumatic Alterations of the Zonule

The readiness with which the normal zonule tears is attested to not only in cataract operations (especially in older persons) but also by the frequency of subluxation and luxation even after moderate degrees of trauma. "The zonular attachment of the lens is of prime importance in maintaining the position of the lens. Much less important are the concavity of the fossa [action of negative pressure - M.L.B] and the connection of the lens to the vitreous by means of the ligamentum hyaloideocapsulare. If the zonule is ruptured completely or relaxed the lens shifts downward due to gravity but complete luxation does not take place until the ligamentum hyloideocapsulare is also torn” (Bellows).

As mentioned in the chapter on injuries to the lens, Frenkel believes that any sudden force applied to the globe which raises the intraocular pressure sufficiently will result in some degree of lens displacement (traumatic syndrome of the anterior segment). He postulates that minimal subluxations practically always occur in this syndrome, although they may not be demonstrable in every case clinically. In this chapter we shall not consider those cases of severe injury or perforating corneal ulcer in which the lens is entirely


Fig. 464. Traumatic dislocation of the lens. Cortical changes (water slits and laminary separation). Note spheroid shape of the lens and absence of peripheral divergence resulting from the absence of zonular fraction. Anterior surface of the vitreous seen above.

extruded from the eye, nor those in which, owing to rupture of the sclera, the lens is displaced into the extraocular tissues (in the subconjunctival space or within Tenon’s capsule) . Neither shall we dwell on those instances in which the lens is totally luxated into the vitreous and is not accessible to biomicroscopic examination. In certain types of injuries, associated with rupture or dialysis of the iris, operative coloboma (especially after excision of prolapsed iris tissue) , shrinkage or lens displacement - it may be possible to inspect the zonular apparatus (Fig. 4(34) .

The degree of zonular damage varies from case to case depending on the local conditions and on whether the lens is subluxated or luxated. In cases in which no discernible dislocation of the lens occurs, and an iris rupture or coloboma exists, the exposed part of the zonule may be studied m situ. The zonular bundles may be stretched, torn and curled or entirely absent. By changing the direction of the light (i.e., causing the light to enter the eye from the nasal as well as from the usual temporal side) it may be found that in places apparently devoid of fiber bundles, that the posterior ones are still


1358


BIOMICROSCOPY OF THE EYE


attached to the lens. Owing to tension these bundles are frequently wedge-shaped, i.e., the angle between them gets smaller the farther their distance from the lens margin. In addition to the deposits on or between the fibers (also seen in ectopia and spherophakia) additional ones may be present derived from the iris (traumatic iritis) or from blood cells (hemorrhage) . In practically every contusion or perforating injury a positive tyndall phenomenon (pigment, white or red cells) in the anterior chamber will be present for a long time. Herniations of the vitreous are not uncommon.

When the lens is displaced, inequalities in depth of the anterior chamber will be noted, and especially in the young the edges of the lens may become undulated. (See Plate LXXVIII, figs. 2, 4, 5, 6.) In older persons this irregularity in contour of the lens equator is more apt to occur after the lens has become opacified. Iridodonesis and phakodonesis may be present. At times in lens displacement, when the tips of the ciliary processes can be seen in a coloboma or through peripheral iris defects, even when the remaining visible zonular fibers are taut, the tips of the ciliary processes may not be under any tension (Fig. 463). This is another indication disproving the older idea that the zonular fibers originated from the ciliary processes. Immediately after complete anterior luxation, if this is unobscured by hemorrhage, the lens released from its zonular attachments tends to appear more spherical than normal (Fig. 464). In diffuse light a clear lens may resemble an air bubble commonly seen after the insertion of a contact lens. However, the passage of the focal beam will reveal the pearly gray relucency normal to the lens (Fig. 460 A) . Usually the iris will be displaced posteriorly. Occasionall}'^ an e^'^e tolerates an anteriorly luxated lens quite well but in most instances, depending on the size of the lens and whether or not the aqueous circulation is interfered with, secondary glaucoma supervenes. Iridocyclitis either preceding, causing or accompanying the rise in intraocular pressure may further complicate the picture.

Several years ago, I saw a patient (a man aged 44) several weeks following a contusion in which the lens was luxated into the anterior chamber. The vision in this eye with a -4.00 D. lens was 20/50- and the intra-ocular pressure was 30 mm. Pilocarpine 2 per cent was instilled and the patient was referred to the hospital for operation. By the time the


THE ZONULE


1359


Vogt describes an unusual phenomenon - separation of the capsule at the equator by fluid, occurring after a perforating injury to the eye. The opaque lens was subluxated into the anterior chamber. Below, stretched-out zonular bundles were seen to be attached to the lens margin. Some of the posterior bundles were present. With the optic section it was seen that the smoothly rounded capsule (with its zonular attachments) was separated from more opaque axial parts by a dark, less-relucent interval. Evidently in this case, owing to increased zonular tension, the total capsule itself was separated from the underljdng equatorial lens substance by fluid. Vogt cites Topelansky who described, in postmortem specimens, collections of fluid at the equator that could occur only if the traction of the zonule were pathologically increased.

TRAUMATIC DETACHMENT OF THE ZONULAR LAMELLA

Traumatic detachment of the zonular lamella in the living eye was first described and seen biomicroscopically by Meesmann (1925) . (See Fig 46^; Plate LXXVIII, fig. 2.) The same year, Vogt described it in hereditary displacements of the lens and considered that there was a definite genetic predisposition for its occurrence (Fig. 466) . In 1940 Serr confirmed Vogt’s findings. Other writers, among whom were Stein, Busacca, Jess and Kronfeld, have described this condition. In Meesmann’s cases (observed six months after injury) a "free floating crinkled membrane” was noted in the area of lens displacement, concentric to but separated from the lens margin. There were no zonular fibers visible. In Stein’s case, in which there was a bilateral upward dislocation of the lens, concentric to the edge of the lens (but somewhat higher) there was a delicate pellicle suspended from the zonular fibers. Some of the fibers were seen freely floating in the anterior chamber. Jess described a case in which the detached

patient reached the operating table his pupil had dilated (psychogenic?) and the lens had fallen back into the vitreous. He was sent back to his room and instructed to lie on his face. The lens just as suddenly fell back into the anterior chamber and the pupil was vigorously contracted with a miyure of pilocarpine, eserine and doryl. With this treatment the lens remained in the anterior chamber and was extracted (with a loop) two days later. Although no vitreous escaped at the time of operation, biomicroscopic examination two weeks later revealed a large bulging herniation of the vitreous into the anterior chamber.



THE ZONULE


1361


zonular lamella and the attached zonular fibers were stained green by impregnation with copper (zonular chalcosis from an intraocular copper foreign body).

Undoubtedly more frequent biomicroscopic examinations in cases of displaced lenses either of hereditary, spontaneous, or traumatic origin will reveal that separation of the zonular lamella is not as rare as was first thought. As previously indicated, the individual nature of this lamella was proved by the fact that it can detach under stress, that this detachment is always limited to the equatorial zone, and that in trauma, unlike heat cataract or senile cataract in which the detachment occurs axially, the zonular lamella does not separate in a flaky fashion,

In heat cataract occasional flakinp iias been noted as a rare finding.

31 The Vitreous

General Considerations

A lthough the fibnliar structure of the vitreous had pre- viously been noted in aphakic eyes, it was not until 19 ii that Gullstrand, using the focused beam, first noticed it in a normal living eye. He said that by oscillating the illuminating lens (which in the original model was held in the hand) it was possible to see several layers of membranes at various depths, and that these membranes formed a network and extended in the frontal plane. In 1914 Erggelet studied the normal and pathologic vitreous in more detail. Later Redslob and especially Koby made definite contributions to biomicroscopy of the vitreous. In 1918 Vogt, employing a new method of projection (see Vol. I, page 5), had just demonstrated the principal of the optic section, obtained by means of a narrow beam. Thus it became possible to obtain sharp optic sections of the living cornea, lens, and vitreous, to the order of 15 p. This advance became the cornerstone of biomicroscopy. In 1924, BedelP®^ elucidated the biomicroscopic appearance of the vitreous. His was the first important publication on this subject by an American writer.

Projection of the beam demonstrates a definite tyndall phenomenon in the vitreous. The fact that the tyndall phenomenon seen biomicroscopically is not homogeneous, as in the case of true colloids and gels, started a mild controversy concerning the physical structure of the vitreous. (See Vol. I, Figs. 6, 70.) Its lack of homogeneity is indicated b}'^ the presence of a framework consisting of multiple layers of vertically suspended bands or curtains, sometimes membranous and other times fibrillar, separated from one another by

1362


THE VITREOUS


1363


darker intervals. The luminosity of the curtains gets progressively weaker in the depths. However, with stronger illuminants, e.g., arclamp, a fibrillar structure is seen even in the darker zones. It should be noted that tlie degree of luminosity varies in the normal eye from case to case. The more or less regularly arranged framework is best seen in the young.

Baurmann and Duke-Elder "" held that if the vitreous were a true gel, it would not be possible to discern any true fibrillar structure in the living state. They felt that since true gels are composed of ultramicroscopic micellae, the reflections which we do see, come from zones of varying indices of refraction and from a sort of moire; the idea being that excepting by means of the moire effect submicroscopic micellae could not be seen with the magnification afforded by the biomicroscope. The appearance of moire (like watered silk) may result from reflections in which mirroring zones alternate with darker ones. A similar effect can be seen by reflection or transillumination in the case of parallel grilles or nets the elements of which cross one another angularly. According to Koby, in order for the vitreous to produce a moire it should be formed of regular parallel elements - sufficiently opaque. This has not been proved. Even with the highest magnification possible and with the strong arc beam, no indication of a parallel crossing fiber system is apparent; such a system was described by Koeppe but has not been verified by any other investigator. Koby cites the fact that Duke-Elder,"' following Baurmann, attributes great importance to the moire (optical effect) which permits one to see ultramicroscopic fibrillae, but that Duke-Elder also points out that fibrillae are not visible in fresh

After commenting on the fact that structures conforming to a fibrillar framework seen histologically can only be artefacts, or coagulation products resulting from fixation and staining processes, Duke-Elder adds, "The appearance seen with the slit-lamp requires a somewhat different explanation. In the beam of the slit-lamp the fibrillae only become evident when large numbers of them are arranged in a direction perpendicular to the incident light. In regions where the arrangement is haphazard, the vitreous appears optically empty, but near the boundary layers where the surface forces orient the micellae in approximately parallel directions and in closer formations, the optical effect is given of a waved or moire appearance suggestive of watered silk or marcelled hair. The appearance of the vitreous is more than usually complicated, for as we shall see it contains internal surfaces within itself but the apparent texture is merely an optical effect, the basis of which is determined by the fibrillar micellae, although they themselves being of submicroscopic dimensions are too small to be rendered actually visible by the slit lamp,”


1364


BIOMICROSCOPY OF THE EYE


specimens of vitreous. Thus Koby concludes that it is not possible to understand what produces the moire and hence he believes that it plays no role in what is seen biomicroscopically in the vitreous. If the images were due to the effect of moire then with movement of the globe or of the beam they should be displaced more rapidly than the anatomic elements. Actually this is not the case. With movements of the beam there is a definite lag and pendulum-like swing in the movements of the visible vitreous formations seen in the tyndall phenomenon. In my opinion the evidence seems to favor the conception that the formations seen in the tyndall beam biomicroscopically represent the true framework of the vitreous.

Technique of Biomicroscopic Examination of the Vitreous

As pointed out by Koby, biomicroscopy of the vitreous is beset by difficulties not only attributable to optical inadequacies of the instrument but also because of the nature and location of vitreous itself. For example, its examination is hampered by the diaphragming action of the iris, its deep location and (chiefly owing to its gel-lilte character) its very weak relucency. Despite these limitations biomicroscopy is still the only available method for the direct examination of the vitreous in the living eye.

Because of the semifluid character of the vitreous, its examination biomicroscopically is restricted to observation by means of direct focal illumination. As in the case of the anterior chamber or even the zonule, morphologic details can only become visible by means of the tyndall phenomenon (Vol. I, page 73). Hence all observations in the vitreous have to be made within or along the passage of the focal beam. The low degree of relucency precludes the possibility of employing retro-illumination or indirect illumination excepting in light reflected from the fundus. Relatively the degree of relucency of the tyndall beam in the normal vitreous, excepting for its lack of homogeneity, is less than that of the normal cornea but is more comparable to that of a slightly turbid aqueous. The fundamental principle to be remembered when examining any part of the eye by direct focal illumination is that the focal part of


1365


THE VITREOUS

the beam and the focal point of the microscope must simultaneously be adjusted to fall on the spot observed. The gel-like structure of the vitreous, with its low degree of relucency, contains no regular stratification of zones of discontinuity, no regularly fixed points of reference. As the beam passes through the cornea and lens we are guided by well-defined surfaces and zones of discontinuity. These are absent in the vitreous. Its posterior surface is not visible normally and anteriorly there is no sharp line of demarcation - the posterior surface of the lens alone indicating its beginning. The focal point of the beam (convergent rays) where the light is most intense, depends on the focal length of the illuminating lens (70 and 100 mm.) augmented by the dioptric power of the media. Hence it follows that using the ordinary biomicroscopic technique, i.e,, without a contact lens, that only the anterior third of the vitreous can fall within the focal part of the beam. This limitation is not as serious as it may appear since most of the changes which occur are visible in these zones. Posteriorly the light (divergent rays) becomes weaker and is dispersed. However, further increase in depth of focus may be obtained by employing diaphragms of 70, 100 or 200 mm. (see Vol. I, page 48) now standard equipment in the Poser model (Bausch & Lomb) .

Another handicap to deeper inspection of the vitreous lies in the fact that owing to limitations of the instrument we are unable to direct microscopic examination along the axis of the beam since the direction of the beam as it enters the eye is angulated to that of observation. This means that it is not possible to project the beam directly in the sagittal plane. To overcome this - to a degree - two maneuvers are resorted to: first, in order to cover as much area as possible, the beam is directed into the eye from the nasal side as well as the temporal, and second, the angle between observation and illumination can progressively be narrowed to almost 30 degrees. But as this angle is sharpened there comes a point at which the

The chief advantage of the loo mm. illuminating lens resides in that, although the intensity of illumination of the beam is somewhat lowered, its longer focus allows us to direct the beam across the nose without the end of the illuminating system touching the patient as might happen when using the 70 mm.


1366


BIOMICROSCOPY OF THE EYE


illuminating lens will strike the microscope and where it will obscure one of the objectives and thus interfere with binocular vision. In addition, as we narrow this angle specular reflexes from the cornea


Fig. 467. Fentoscopy. Appearance of the beam passing into the eye (observation with the

unaided eye).

may cause annoyance. The binocular microscope commonly emplo5’'ed (Vol. I, page 28) has two paired objectives, the frontal ends of which converge so that there is a distance of 2 or 3 mm. between them. Consequently the distance between their optical centers measures from 12 to 13 mm. It will be readily realized that unless the pupil is widely dilated (at least to 5 mm.) the margins of the iris will prevent observation of the vitreous through one of the objectives i.e., the one farther away from the light. Koeppe, LopezLacarere, Goldmann and Kleefeld have devised certain modifications to overcome some of these diflSculties - but in each case added supplementary equipment (mirror or prism and contact lens) lowered the intensity of the focal beam. These modifications will be considered later. If they are not available one must not forget to use the ophthalmoscope with plus 4 to plus ^ lenses, since by this means opacities in the posterior part of the vitreous which are not overdelicate ma}^ be brought into view.

The beginner must also be cautioned about the possibility of striking the cornea when employing the longer high-powered objectives. To avoid this one adjusts the microscope so that the frontal ends of the objectives just clear the cornea and then safely focuses by racking the microscope backward. In view of all this, although a maximum magnification of 60 X can be used, practically a magnification of 24 X is suflScient to bring out even minimal pathologic changes.


THE VITREOUS


1367


I have always advised students to observe the passage of the beam with the unaided eye - fentoscopy (Koby) - since much information can be obtained by this oft-disregarded procedure (Fig. 4^7)Macroscopically it is possible to see gross disturbances in the vitreous structure. With e)^e movement, normal as well as pathologic trabecular formations are seen to oscillate. Cellular deposits give a definite increase in the tj'-ndall dispersion, and even the color of the cellular components can be recognized. Actually the red color of blood can be recognized better macroscopically than microscopically. Under magnification, single erythrocytes appear as whitish or yellow-white, shining points. Another interesting feature that can be observed macroscopically is that while moving the beam across the pupil and directing the observer’s vision along the axis of the beam, a reddish glow may be perceived which illuminates not only the beam (tyndall) but also the neighboring areas. This form of illumination (page 743 and page 981) results from light reflected from the fundus, which in a sense serves as a concave mirror. When detachment of the posterior limiting layer of the vitreous extends anteriorly, it can be diagnosed macroscopically.

Unquestionably the tyndall phenomenon, as obtained by the focused beam, is enhanced as the intensity of illumination is increased. Therefore early workers in this field resorted to the carbonarc lamp as a light source. Although this does bring out considerably more details (especially when used in association with the narrow slit opening) practically, from the standpoint of everyda})^ clinical work its use is not entirely without drawbacks. Even under the best circumstances the light is unsteady and requires constant adjustment. Stronger illumination can be obtained from the nitra lamp if it is overloaded up to 12 to 14 volts. However, I have found that with the stronger light source now available, i.e., with the Koeppe-Poser system, adequate illumination can be obtained. After focusing the posterior lens capsule - as a point of reference - using the narrow beam (optic section) the width of the slit should gradually be increased until details in the underlying vitreous become sufficiently visible, or conversely, one may focus on the' posterior capsule


1368


BIOMICROSCOPY OF THE EYE


•with the wide beam and then gradually narrow it until the posterior line of disjunction of the lens differentiates itself from the capsule stripe - an indication that an optic section of sufficiently small width has been reached. Also by overloading the lamp the tyndall phenomenon and hence the trabecular structure becomes increasingly visible. Even with the unaided eye it will be seen that the more luminous layers are interrupted by relatively dark ones. The anterior ones are most luminous and the most anterior is the most luminous of all. The presence of such variations in the tyndall dispersion of the vitreous proves that it is not homogeneous, as would be expected if it were a true gel. Not infrequently, particularly in cases where the vitreous (even when it is normal) is of low relucency the slit may have to be opened maximally. The conical bundle as obtained from the round openings in the diaphragm is also useful (as in the anterior chamber) for finding varying degrees of relucency (at different levels) and for localization. Koby recommends the astigmatic bundle (see Vol. I, page 21 ) because of its homogeneity and increased luminosity (three times that of the ordinary one obtained with Vogt’s method of projection) . However, the height of the beam becomes disturbingly elongated.

As pointed out in the section on technique of biomicroscopy (Vol. I, page 64) it is not necessary to keep the examining room in total darkness - sufficient light should be present to permit the examiner to make adjustments in the apparatus and to watch that the patient keeps his head steady by means of both the chin rest and the head guard. It is preferable to have the patient gaze directly ahead rather than toward the microscope or into the light. Also it is better to make changes in directions of illumination and observation by altering the relative position of the miscroscope and illuminating lens, than to have him constantly change the direction of his gaze - since ordinarily on command his excursion will be too wide. However, there are times when slight movements (especially vertical) will serve to bring out certain details (see page 1379). Without employing the microscope, the beam of medium width is projected into the dilated pupil (when dilatation is feasible) - first from the


1369


THE VITREOUS

temporal side and then from the nasal side; the beam is then brought to a sharp focus at the posterior capsule. The tyndall effect of the beam is then studied as the intensity of the light is increased, i.e., by widening the slit and by decreasing the resistance of the rheostat. By looking somewhat over or below the beam, the observer with the unaided eye can direct his gaze along the axis of the beam, a procedure not easily possible when using the microscope. The beginner will frequently be surprised by the fact that a tyndall effect in the vitreous may be obtained even in the presence of considerable change in the lens - although dense central opacification will tend to impede it more than peripheral ones. Corneal opacification offers greater hindrance. After having made observations by means of the naked eye, the examiner proceeds to observe the tyndall by means of the microscope - starting with low powers of magnification. In order to obtain deep penetration the angle between illumination and observation should be as narrow as possible. Again, changes in direction and intensity of the beam should be made in order to cover as much area as possible and in order to bring out the maximum tyndall effect as strongly as possible. As the direction of beam is slightly displaced from side to side, one will notice that the more luminous constituents (curtains) move naturally in the same direction but not exactly at the same rate of speed. When pathologic changes are found, it is always good practice to study the fellow eye immediately - for the purposes of comparison. Quick changes in observation from eye to eye will serve to accent the relative differences in appearance. As Bedell (1924) has stressed, prolonged and leisurely observation of the vitreous very frequently brings out parts that otherwise would be glossed over in more hurried inspections.

.x^ioMicRoscopic Appearance of the Normal Vitreous

Normally the structure and luminosity of the vitreous is extremely variable even in persons of the same age. Its appearance also changes as the individual grows older, and eventually in the aged it may assume characteristics which by themselves may not be differentiated from changes due to pathologic processes^ V ariabihty in the


1370


BIOMICROSCOPY OF THE EYE


relucency of the vitreous tyndall phenomena may be so great that extremes in the degree of visibility of the framework result. In one case the latter may be practically invisible, while in another it may


}


/


Fig. 468. Diagrammatic representation of the normal vitreous. To the left, posterior lens capsule with the attached remains of the hyaloid vessel. The latter is seen suspended in the retrolental space or in the hyaloid vitreous (H.V.). The hyaloid (primary) vitreous is composed of delicate striae. Deeper is the definitive (secondary) vitreous (D.V.) with its plicated surface (merabrana plicata) well demarcated.

be highly luminous and easily seen. Such contrasts in normal eyes probably result from varying differences in the indices of refraction between the component parts of the vitreous. When the difference in indices of refraction between the framework and its more fluid parts is minute, then the visibility will be very low. For purposes of illustration Koby cites the work of Veragut, who, with the nitra lamp, roughly estimated variations in relucency of the vitreous in a group of 82 children as follows: very luminous framework, 6 per cent; fairly luminous framework, 44 per cent; slightly luminous ^mework, 50 per cent.

'^As the beam penetrates the vitreous, an optic section (tyndall phenomenon) is formed. The width and relative luminosity of this section depend on the width of the slit opening and intensity of the


1371


THE VITREOUS

beam. With the nitra lamp, a dark space (so-called retrolental space”) lies between it and the posterior capsule. However, with the arc lamp (Erggelet) or the stronger illumination now available


Fig. 469. Frontal view of membrana pHcala showing details under high power.

with the Poser apparatus, it will be found that a faint tyndall effect occurs in this dark area and demonstrates a fine fibrillar network - in other words vitreous and not simple aqueous (Fig. 468). This may represent the embryonal primary vitreous (hyaloid) - an idea strengthened by the frequent finding of traversing vascular remains. Immediately behind this area is the definitive or main part of the vitreous (secondary) which is indicated by the appearance of a more definite tyndall effect and the plicated membrane, (immediately behind the so-called “retrolental space,” luminous “layers” or “bands” appear (in lieu of a better name for something uncertain) which run more or less parallel and are interrupted by narrower, less relucent or dark layers. These so-called "dark” spaces are only so relatively; with higher degrees of illumination and with


1372


BIOMICROSCOPY OF THE EYE


changes in direction of the beam they are not optically homogeneous but contain delicate fibrillar structures. The transition from a dark to lighter area occurs rapidly in a “sinuous line” upon movements of the beam. The anterior bands are more luminous and regular than those behind them which gradually fade in the depths, the most anterior having the highest luminosity (Fig. 469). These curtain-like bands hang vertically, their direction having no relationship to the direction of light. Changes in position of the head or eye will cause them to float but, owing to gravity, they will always resume their vertically hanging position, 'j

According to Koby, variations in the appearance of the anterior band make it possible to distinguish two extreme types of structure. Thus two schools of thought arose. This apparently resulted from variation in density of the luminous parts. The first group (Koeppe, Koby, and Mann) postulated that the vitreous had a fibrillar structure and the second (Gullstrand, Erggelet, Vogt, Dejean) that it was lamellar, pseudo lamellar or membranous, later Koby stated that both forms occur (Figs. 470, 471, 472). Both groups agree that the luminous parts are reflections from zones of discontinuity. But as Koby asks, “To what do the darker or less luminous parts correspond?” Those that consider the structure to be membranous think that the dark parts are due to unlighted portions of the folds. In this case, lateral movements of the light should cause the dark parts to become luminous. It has not been possible to demonstrate this. Koby thinks that the alternating light and dark areas ma} represent uniform differences of density in the same surface or perhaps, as suggested by Redslob, because of an irregular arrangement in layers, certain areas become more dense and hence more luminous. In this way the alternating dark and light parts could be explained partly by the presence of true folds in the pseudomembrane and partly by the heterogeneity of its structure. As Koby puts it, in spite of the several theories concerning the structure of the vitreous - i.e., whether it is formed of homogeneous membranes, Isolated fibers, or other unique colloidal structures - not one of them explains in an entirely satisfactory way its biomicroscopic ap


Fig. 470. Normal vitreous of membranous type. Young person. Lens normal. Remnants of hyaloid vessels attached to the posterior lens capsule. Main remnant hanging dependently in the hyaloid vitreous, which is characterized by a fine oblique striation. The anterior band or surface of the definitive vitreous is very luminous, appearing as a finely pleated membrane (membrana plicata). Deeper there is another pseudomembrane, less luminous and less well defined. (After Koby.)


Fig. 471. Normal vitreous of the membranous type.


1373


1374


BIOMICROSCOPY OF THE EYE


pearance and physical properties. It is the biomicroscope which provides the most realistic picture and no theory concerning its structure is acceptable unless it harmonizes with this picture.


Fig. 472. Normal vitreous of the fibrillar type. Young person. Notice the numerous obliquely running bands which are finely striated and seem to anastomose in some places.


Vogt has compared the frontal reflecting bands of the vitreous framework to hanging drapes, vertically folded. The first of the anterior bands, being the most luminous, shows the angulated folds best. This is sometimes known as the plicated membrane (Fig. 469). It probably represents the anterior boundary of the secondary vitreous and hence there is good reason to believe that it corresponds to the upper boundary of Cloquet’s canal. In agreement with Fuchs, ^^ogt considers that the vitreous has a lamellar or membranous structure and that the lamellae in turn are composed of fibrillae. The fibrillar structure becomes especially apparent in pathologic states. Vogt intimates that a purely fibrillar structure may be seen in many normal eyes but that with increased illumination their membranous character becomes more apparent. Evidently the form and position of these scaffolding membranes or perhaps better pseudomembranes, is a result of their specific weight, which is greater than that of the surrounding vitreous fluid. Owing to some degree of fixation since the scaffold is probably attached to and suspended


THE VITREOUS


1375


from the so-called base of the vitreous (Salzmann) in the region of the flat portion of the ciliary body, movements of the eye cause it to have pendulum-like movements. But in these movements it quickly returns to its original position. In addition to the vertical folds Vogt called attention to crossing stripes (due to horizontal folds?) which gives the normal framework its characteristic appearancej)Koeppe, using the Nernst-lamp, described systems of regular nets consisting of parallel crossed fibers (horizontal and vertical) . No other investigators have been able to verify the presence of such regular systems. As the deeper parts of the vitreous are brought into focus the vitreous bands become less luminous and less orderly. Frequently it will be observed that the vertical and parallel arrangement of these structures is limited by the first two or three bands, (j’he deeper ones become irregularly tortuous and sinuous so that no regular directions can be attributed to them.^Consequently the)’^ lose the curtain-like effect of the frontal layers so characteristic of the normal vitreous structure in the young.^With slight movements of the beam, this irregularity gives the impression that connections exist between the lamellae and that perhaps in these parts no orderly stratification exists. As the light is angulated, it will be seen that peripherally (as far as is possible to see) the relucency of the tyndall effect may be greater than in the axial region, the structure appearing more fibrillar./ From the standpoint of biomicroscopic appearance it may be sam that the vitreous is a complex gellike substance, having a structure or framework in the form of loose, nonhomogeneous layers, lamellae, or pseudomembranes; that these lamellae, which vary in thickness, are constituted of irregular conglomerations of fibrillae; that in it we can see vascular rests and divisions (i.e., the retrolental space with its contained hyaloid or primary vitreous and the definitive or secondary vitreous) indicative of its embryologic development.^^

THE RETROLENTAL SPACE AND THE HYALOID VITREOUS

The so-called “retrolental space” is bounded anteriorly by the posterior surface of the lens and posteriorly by the first band of the secondary, or definitive, vitreous. (See Figs. 468, 470, 472.) In cer


1376


BIOMICROSCOPY OF THE EYE


tain pathologic conditions the division between these parts becomes uncertain. This space can easily be seen even with the unaided eye. Focus of the beam upon the posterior lens capsule will reveal a dark interval between the back of the lens and the plane marking the onset of the vitreous tyndall effect. This retrolental area also is known as the "space of Berger.” Depending on the posterior curvature of the lens, it will be seen that this space is shallower axially and gradually increases in depth toward the periphery. Its extreme peripheral boundaries cannot be seen. Some of the earlier writers considered the retrolental space to be "optically empty,” its relucency corresponding to that of the aqueous. As previously mentioned, with improved illumination (especially with the arc lamp) it soon became apparent that this area contained a delicate fibrillar striation.’*'’ Even with the ordinary nitra lamp, if the observer is slightly dark adapted and persistent (similar to the conditions required for bringing out the physiologic flare of the anterior chamber) , he will, after gradually increasing the intensity of illumination, suddenly become aware of this delicate fibrillar striation. These fibers in traversing the space tend to run obliquely from above downward (Fig. 472). According to Koby, the contents of this area are not generally homogenous, and frequently two or three pockets of varying optical densities will be found. It should be emphasized that at best the tyndall effect in the retrolental space (primary or hyaloid vitreous) falls just within the limits of visibility and hence does not interfere with the sharp demarcation of the less homogeneous secondary or definitive vitreous behind it.

During embryonic development the primary vitreous contains the hyaloid system of vessels. Later, as a consequence of either pressure of the secondary vitreous or condensation of its fibrillae, the boundaries of Cloquet’s canal are formed. In this way the primary vitreous becomes enclosed. According to Ida Mann the direction of the vestiges of the vessels and the boundaries of Cloquet’s canal in the fetus and even for some time later in the young have a some

This was first emphasized by Erggelet. It will be readily understood that the depth and dark contrast of this space becomes greater with less illumination.


1377


THE VITREOUS

what sagittal direction. With time, the npper boundary of Cloquet’s canal becomes increasingly convex frontally and with its vascular remains sinks so that gradually a vertical direction is assumed (Fig* A B


C

Fig. 473, A. Cloquet’s canal in the newborn. The "entennoir" of Cloquet’s canal is very large, the hyaloid vestige is horizontal in direction, b. Cloquet’s canal in a young person, c. The effacement of the canal in an adult. (After Mann.)

473). In other words, the vertical anterior band (originally the upper boundary of Cloquet’s canal) now limits posteriorly the socalled "retrolentai space” with its contained vestige of the primary vitreous and vasa hyaloidea propria. It is therefore appropriate to


Fig. 474. Dark pocket above Cloquet’s canal in myopia. Opacity in shape of a veil in the case of retinal detachment. Behind posterior capsule of the lens there is a zone of increased optical relucency formed of delicate fibrils. Deeper to this there is a darker zone in which remnants of the hyaloid vessels are seen. Still deeper there is a thick layer seemingly formed by a great number of fine membranes. This layer then turns upwards enclosing a cul de sac - optically empty. The limiting posterior layer of the pocket appears to be especially luminous and fibrous. (Modified after Koby.)


Fig. 475. Rests of the hyaloid vessels located deep in the hyaloid vitreous. Note condensations

where the fibers cross or anastomose.


1378


THE VITREOUS


1379


call this the "hyaloid vitreous.” At the same time it forms the anterior limit of the more relucent deeper secondary or definitive vitreous. The above phenomenon also explains the observation made


Fig. 476. Filiform rests of the hyaloid vessels located on the surface of the definitive vitreous and confined to the frontal plane. The rctrolental space i is dark, deeper to this there is a wider zone 2 which contains wormlike filiform and anastomosing opacities. Still deeper (3) is another zone of lesser relucency with linear figures.


by Koby, that the direction of the anterior band of the definitive vitreous is somewhat obliquely backward from above down and thus causes the depth of the retrolental space to be greater below than above (Fig. 471 )- By having the patient direct his gaze upward and then back to the horizontal level, it frequently is possible for an instant to cause the anterior vertical band to float back to the original embryonic (?) horizontal direction. By focusing below this, another wavy horizontally directed band may appear, which, perhaps, represents the inferior limit of the canal. Koby has also described the finding of invaginated pockets, especially in myopes. These pockets, located in the anterior parts of the definitive vitreous, appear almost optically empty. They resemble the letter U, with the opening directed superiorly (Fig. 474). He believes that they are related to Cloquet’s canal. Such appearances might also be associated with detachments of vitreous (page 1410). Another fact


1380


BIOMICROSCOPY OF THE EYE


Strengthening the conception that the vitreous in the retrolental space corresponds to the embryologic primary vitreous is the almost universal finding of irregular filiform structures that are not attached to the lens. They may lie on the surface of the anterior band (membrana plicata). (See Figs. 475, 476.) They tend to run more or less vertically and frequently are "somewhat entangled and anastomosed.” It is generally agreed that these threadlike structures are vestiges of the vasa hyaloidea propria. They are easily distinguished from the framework of the definitive vitreous by their more intense white color and ravelled thready character. Upon vertical eye movements these as well as the small corkscrew filament which is so often found attached to the posterior lens surface can be caused to float out horizontally. The latter returns only very slowly to its dependent position. The remains of the vascular system which are found attached to the posterior capsule were discussed in the section on the lens. In the normal eye, I have never seen any portion of the definitive vitreous attached to the lens. However, this may occur when the vitreous is altered pathologically.

Special Methods Devised for the Examination of the

Vitreous and Fundus

In order to observe the posterior two-thirds of the vitreous, Koeppe applied the principles of "orthoscopy” in the form of a contact lens of about - 54D. As a result, the convergent action of the anterior media (cornea and lens) was counteracted in such a way that, optically, the posterior parts of the eye were brought within the field of observation (Fig. 477). To avoid the pupillary border of the iris, the beam of light had to be directed deeply into the eye, thus forming a very acute angle with the anteroposterior diameter of the eye. This was accomplished by a tiny mirror affixed to the distal extremity of the arm of the slit lamp, the latter being directed more or less tangentially to the observed cornea. However, with this method, Koeppe was unable to employ the strong objectives of the ordinary Czapski binocular microscope. This was due to the fact that the mirror which was attached to the illuminat


1381


THE VITREOUS

ing lens either completely or partially covered one of the objectives. Hence binocular vision, so vital to this method, was interfered with. Therefore he decided to replace the Czapski by the


Fig. 477. Diagram of Koeppe's method for the examination of the retina and deeper vitreous.


Fig. 479

Fig. 478. Koeppe’s method - ^instrument ready for use.

Fig. 479. Kieefeld’s instrument. A modification of the Koeppe method.


uniobjective binocular microscope built by Seidentopf and called Bitumi (Zeiss). (See Vol. I, page 28.) With this microscope the light enters the objective and then is split by prisms so that half is received by each ocular. All Koeppe’s studies with respect to the vitreous body, and the fundus oculi as well, were done by means of this method (Fig. 478) .


1382


BIOMICROSCOPY OF THE EYE


It should be remembered that Wolff (1912) (see Vol. I, page 5) was the first to employ a method for examination of the fundus by means of focal light. Other types of ophthalmoscope permitting the


Fig. 480 Fig. 481

Fig. 480. Zamenhof’s modification of the simplified Gullstrand ophthalmoscope.

Fig. 481. Above: Kleefeld’s modification ofi Zamenhofs method. Below; Photographs of different vitreous opacities. (After Kleefeld.)

use of a focal slit beam were developed by Thorner, Friedenwald and- Evans.

Shortly after the publication of Koeppe’s paper, Kleefeld (1922), changing the direction of the beam, proved that the Czapski microscope could be used with a contact lens. By having the light source above and by directing the beam horizontally into the eye by means of a mirror, it was possible to get an unobstructed view of the deeper vitreous. The mirror was attached to the end of the slit lamp arm and not to the illuminating lens (Fig. 479) as is the case in the Koeppe method.

The contact lens enables the use of high magnification. Without unnecessarily^ increasing the strength of the oculars a magnification of 36 diameters is obtained easily with good stereoscopic vision.

In 1935, Lopez Lacarrere had an apparatus constructed in which both the illuminating and observational systems were placed on a single supporting arm. This permitted observation along the beam’s



THE VITREOUS


1383


axis. Also, with this objective in mind Lopez Enriquez (1935) employed two plane silvered mirrors.

Recently, Lindner (1936) devised a simplified monocular microscope having a reflecting prism which permits, to a degree, observation along the axis of the beam. A contact lens is also used. I have tried both the Koeppe and Lindner methods and must confess that I agree with other workers in this field that the) are difficult and uncertain. For one thing the application of the contact lens tends to contract the pupil. One also must constantly guard against fogging of the contact lens itself, and with the patient’s head in the upright position it is necessary to support the glass in order to keep it from slipping. In addition disturbing specular reflexes from the glass interfere with observations.’*' With the Lindner microscope I was unable to obtain sufficient magnification.

Zamenhof, adding a movable lens (+32 diophers) to the Simplified Gullstrand ophthalmoscope, devised a method for examining the vitreous, and the fundus as well, without a contact lens (Fig. 480). By the addition of the lens, he was able to obtain a focal beam. The binocular stereoscope system of this instrument gives a magnification of 24 X . Although this magnification should be sufficient, fewer details are observed than with the contact glass methods. Nevertheless it is possible to study, for instance, detachment of the vitreous. With the Zamenhof modification of the simple Gullstrand ophthalmoscope it is difficult to examine the lower parts of the vitreous body because of the dark shadow in the lower part of the pupil. With the aid of a metal ring Kleefeld, in 1937,^'^'’ modified this apparatus so that it was possible to inspect the lower part of the vitreous as well (Fig. 481). In addition, he suggested a method for localization, mensuration and even photography of vitreous opacities. It should be noted that in all these methods in which the illumination penetrates to the posterior part of the eye, the pink

Modern molded contact lenses fitted beneath the eyelids may obviate this objection to a certain degree. The use of wetting agents offsets the fogging of the contact lens which hitherto has been a considerable difficulty. Furthermore the patient may be examined in a sitting position. Recently Bausch and Lomb have constructed a plastic contact lens similar in principal to the one devised by Allen for gonioscopy. At the time of writing this was in the experimental stage.


1384


BIOMICROSCOPY OF THE EYE


reflex of the fundus, as in ophthalmoscopy, interferes with observations of delicate vitreous changes. The latter can be seen only by virtue of diffraction circles, an optical phenomenon dependent on


Fig. 482. A. Goldmann angle reduction prism: 3, Illuminating lens at end of slit lamp arm;

14, four-sided prism showing double internal reflection giving reduction of the angle between the illuminating beam and axis of the microscope. B, The angle reduction prism attached to the slit lamp; 2, rectangular diaphragm on arm of illuminating system; 3, illuminating lens;

15, lever for rotating prism through 180 degrees; /, central mounting pivot allowing prism to be swung into alternative sections h and h, whether in use or not.


the tyndall effect and requiring a focused beam against a dark background.

In 1937, Goldmann demonstrated for the first time at the International Ophthalmological Congress in Cairo an improved biomicroscope produced by the firm of Haag-Streit. (See Vol. L, page j6.) By means of a prism and a contact lens, examination of posterior sections of the vitreous and fundus in focal light became feasible and practical. For the purpose of satisfactorily reducing the angle between the light beam and the direction of observation (which must be very acute) he employed a four-sided prism placed in front of the illuminating lens. The arrangement is illustrated in Fig. 482 A. The light beam, on leaving the illuminating lens, undergoes double internal reflection in this prism and is so diverted that the effective angle between the axis of illumination and that of the microscope can be reduced by about 13°. The prism (14) is rotatable through


THE VITREOUS


1385


i8o° around the principal axis of the illuminating beam as shown in Figure 482 B by means of the lever (15). With the prism the intensity of the diverted light beam is greater than that obtained with a mirror.

In conjunction with this system Goldmann uses a contact lens made of artificial glass (plexiglass). This lens is very light in weight (0.8 grams) and hence is easily retained with the patient’s head in the upright position. Recently he designed such a contact lens having two depressions located in the horizontal meridian so as to facilitate easy insertion and removal. This contact lens has a diameter of 20 mm. with an anterior worked surface 12 mm. wide, having a radius of 70 mm.

It is quite possible to obtain a satisfactory view (in focal illumination) of the deeper vitreous and fundus without the use of a contact lens. In 1923 Lemoine and Valois suggested this possibility. They placed a strong concave lens in front of the patient’s eye. However, their system of illumination was diffuse. Lately Hruby (Figs. 483) using a focal beam, employed such a lens ( - 54 diopters with its anterior surface T 4 diopters) to lessen reflection. I have employed such lens mounted in a trial frame and placed directly in front of the patient’s eye. The axis of the beam was deviated by means of Koeppe mirrors (standard equipment of the Poser slit lamp, Bausch & Lomb; see Vol. I, page 50 and Fig. 48) or by a modified prism (still experimental, Berliner-Priestley) .

The ability to obtain optic sections (narrow beam) in the examination of the posterior parts of the vitreous and retina will certainly assist us in clearing up many hitherto questionable points in diagnosis as well as elucidating the mechanism with which such changes develop. Although the use of the Hruby lens obviates the need for a contact lens, on the other hand the size of the field of vision obtained by means of it is smaller than that afforded by the contact lens. Also it is more difficult to view the myopic fundus with the Hruby lens.

For example, it is possible to localize the posterior limiting layer of the vitreous; to see changes in retinal thickness, to determine elevations or depressions in the retina (particularly in the fovea)


Fig. 483 A. Hruby diagnostic lens (courtesy of A. H. Parsons Laboratories, San Francisco) b Berliner-Priestley prism. C. Contact lens (Goldmann).


rm


• w


Fig. 484. Retinal tear as seen with the Hurby glass. Note strand of vitreous below, pulling

tongue of retina forward. Retina detached.


THE VITREOUS


1387


and especially to diagnose separation or adhesions between the vitreous and retina, and similar alterations between retina and choroid. In a case of retinal detachment (Fig. 484) I was able to observe a tag of vitreous adherent to and exerting forward traction on the tongue of a retinal tear.

Through the courtesy of Prof. Dr. Hans Goldmann I am reproducing several interesting cases from his clinic reported on by Katharina Baumgerten-Blaser (Plate LXXIX, figs. 1-6). In this report the pictures seen by means of ordinary and red-free ophthalmoscopy were compared with those seen by means of focal illumination (narrow beam) and contact lens. In all instances certain important details could only be recognized by the latter method. The observations were made with the Goldmann apparatus and contact lens.


Congenital Anomalies

Congenital anomalies of the vitreous, as far as they can be recognized, are all related to vestiges of the fetal vascular system (hyaloid arteries and its tributaries). The filiform threads behind the lens, the arcuate line, the hyaloid corpuscle, and the attached corkscrewlike remains of the hyaloid artery on the posterior lens capsule are so universal that they can be considered as physiologic. These have been discussed in the section on the lens (page 1024). Hence, in this section only those vestiges that have unusual forms or location will be considered. As suggested by Reese and Payne (page 1394) all these anomalies probably represent forms of abnormalities of the primary vitreous. Examination of the literature reveals only a few reports concerning such anomalous remains. Three main types will be described: (i) striate and pigmented stars on the posterior capsule, (2) the so-called retrolental fibroplasia and (3) congenital vitreous cysts (free-floating or fixed).

Striate or Linear Figures. These may be seen either localized or disseminated on the posterior lens capsule in the form of regular striae or curved lines, grayish white in color. When closely matted, they may form star figures or larger netlike membranes. Like the


PLATE LXXIX- Fig. I. Retinal detachment with macular cyst, three years following injury. Flat retinal detachment extending from above to below disc and macula (retinal folds) . Macula region raised and surrounded by area of small honeycomb cysts. Question as to the presence of a hole or elevation in macula.

SVit-Jamp: With the optic section the protrusion in the macula can be seen as an elevated line. Many small cysts are visible. The superficial line of the light beam is not interrupted over the central area but rather becomes threadlike and more convex. This would indicate the presence of a large cyst with an extremely thin anterior wall. In the region of the cyst the beam can be clearly seen while adjacently it becomes more hazy. More peripherally the beam becomes sharper again indicating a flat detachment. In the central cyst the choroidal line has a yellowish tint which suggests that it is in the region of the macula lutea and that it includes some retinal tissue. Small white spot on the anterior wall cyst is evidently caused by a thickening of tissue about the end of the vessel.

Fig. 2. Senile macular degeneration with hole formation. Male 76 years of age. Thrombosis of branch of lower temporal vein (not seen in illustration).

Slit-lamp: The narrow beam (light directed from the left) shows a round defect comprising all the retinal layers. The choroidal line of illumination (more yellow) proceeds without interruption across the bottom of the hole indicating that the floor is formed of choroid. The floor is tigroid in character.

Fig. 3. Macula changes. Choroiditis serosa centralis. Male 34 years of age, case referred to clinic with diagnosis of acute retrobulbar neuritis. Within two weeks vision reduced to o. 6. variable central scotoma especially for blue.

Slit-lamp: The narrow beam (light directed from the right) discloses that the retinal surface is slightly raised, but in the center, the foveola is seen just below the surface. The retina itself is transparent. Its posterior margin is unsharp. Beyond this is a clear space (optically empty) . Many small yellowish points lie in front of this space. Later central edema disappeared.

Fig. 4. Changes following contusion. Pre-retinal hemorrhage; male 27 years old. Fell from a horse. Head and right eye were injured by helmet. Hemorrhage below macula shaped like bicorne "Napoleon’s hat.” Purtschers retinopathy. Vision I . Small central scotoma. Vitreous haz}^

Slit-lamp: Remnants of blood in vitreous. In the macula region there is a detachment of the posterior limiting layer of the vitreous. In a sac formed by this detachment there is a bicorne shaped hemorrhage (pre-retinal). Above, there is a haZ)’’ fluid filled with cells and limited posteriorally by the sharp retinal line (Light

Courtesy of Dr. Hans Goldmann.

1388


PLATE LXXIX- Coat hiual


directed from the left) . No retinal edema. Above the line of hemorrhage there is a hazy fluid-like collection of fibrin, and phantom red and white cells. Two months later the vision was i.

Fig. 5. Extreme vitreous detachment. Male aS years of age who one year previously had periphlebitis.

Slit-Javip: The light is directed from the right. Notice that the retinal posterior limiting layer of tlic vitreous is displaced forward near the lens. A band of vitreous seen faintly extends towards the retina. Retinal line of illumination is intact.

Fig. 6 . Recurrent vitreous hemorrhage. Ivlalc 55 years of age. Retinal detachment.

SJif-Iavip: Flat retinal detachment. Below in the region of the detached retina there is an extended red line marking the hemorrhage. Above this line is a triangular retinal hole. The slit-lamp shows that the convex blood line dcmarcs the place where the vitreous is separated from the retina. Above the line where the retina and vitreous are still together there is a collection of blood in the form of horizontal stripes. The vitreous detachment has only advanced to the immediate neighborhood of the retinal tear. From this point on the retina and vitreous start being lifted together.

The mechanism of the causation of recurrent hemorrhages and tear formation is as follows: The vitreous detachment starts as usual above. In doing this it damages the retinal vessels causing hemorrhages especially in older persons. It is a common observation that retinal detachment may be initiated by vitreous hemorrhages. As the vitreous detachment progresses it may cause small hemorrhages and finally produces a tear in the retina below at a time when the vitreous detachment has already far progressed.


1591


1392


BIOMICROSCOPY OF THE EYE


so-called "physiologic” remains on the posterior capsule, these are rarely pigmented (Fig. 485).

'Pigmented Stars. Both Streiff and Collivati have reported the


Fig. 485. Striate and linear figures on the posterior lens capsule with unusual attachment of

the rests of the hyaloid system.

finding of pigmented stars on the posterior lens capsule like those more commonly seen on the anterior lens capsule. However, these stars were associated with other anomalies (coloboma iridis, aplasia of the posterior retinal layer of the iris, and congenital subluxation of the lens) . In two of Collivati’s cases, the pigment stars were found anteriorl)'^ and posteriorly at the equator. Pigmentation of the zonular fibers as well as the vitreous occurred in one case.

RetroJental Fibroplasia. Attention was called to a massive growth of embryonic connective tissue in the meshwork of a persistent tunica vasculosa lentis by Terry (1941).®^“ It is associated with prematurity. Normally, during fetal development, regression of the tunica vasculosa lentis occurs at 8^2 months. Hence in prematurely born infants these vessels are present, Terry suggests that as a consequence of light stimulation fibroplasia occurs in the exposed vascular meshwork (Fig. 486). This is seen as an opaque vascularized tissue behind the crystalline lens in which the vessels tend to radiate from a central point. His theory stresses the motor action of light in that "active pupillary responses could embarrass the venous drain


1394


BIOMICROSCOPY OF THE EYE


age of the tunica vasculosa lends by stretching and kinking the vessels as they extend from the posterior surface around the pupillary margin to the anterior surface of the lens.” “Passive congestion in


Fig. 487. A portion of the human eye showing persistence and hyperplasia of the primary \itreous corresponding to Clinical Type I. The retrolental fibrous mass is shown at A, the hyaloid arter}- at B. The lens is small. Ciliary processes, C and Cj, extend to the fibrous mass and the retina is seen as far up as D. (Reese.)

itself is not presumed to cause fibrosis, but the edema associated with it can produce fibrosis such as is seen in the so-called pulmonary osteo-arthropathies.”

It has been noted that contraction and partial resolution of the fibroplastic tissue may occur when further development of the eye takes place postnatally provided no untoward complications arise (hemorrhage, glaucoma, and posterior synechiae).

In summarizing his discussion Terry stated: “Over 10 per cent of infants born very prematurely, weighing 3 pounds or less at birth, can be expected to be blind from retrolental fibroplasia. . . . The typical characteristics of the disease are opaque vascularized membrane behind the lens, microphthalmia, shallow anterior chambers, fetal-blue color of the iris, thin ciliary processes in front of the opaque tissue, searching nystagmus, apparent photophobia, persistent hyaloid artery, and often retinal separation.”

Reese and Payne reporting on 50 cases believe that retrolental


.Tnd P.une, Arr.. ]. OpLib., Vol. 29, No. i, Januar)' 1946.

THE VITREOUS


1395


fibroplasia represents only one type of abnormality of the primary vitreous, and they prefer to designate the lesions as "persistence and hyperplasia of the primary vitreous,” They state: "Terry em-. ployed the term 'retrolental fibroplasia’ to designate primarily a condition occurring bilaterally in premature babies after birth (not earlier than four months) . He felt that this is a new, acquired condition different from the lesion which is unilateral at the time of birth in full-term infants. From the study of our cases and the literature we do not believe such a distinction is justified but that the same lesion may occur in both premature and full-term babies, that it may be unilateral or bilateral, and that all are congenital but may not manifest themselves until sometime after birth cither because the) are not looked for or because the lesion progresses.”

The reason for the apparent increase in incidence of this condition of late is probably related to the present lower mortality rate of premature infants. These authors divide the clinical manifestation into four types as follows:

"I. Saucer-shaped, whitish opaque tissue conforming to the posterior surface of the lens (Fig. 487).

IL An opaque cornea, greatest in the central portion, usually associated with glaucoma, and maybe buphthalmos.

III. A localized area of opaque tissue on the posterior surface of the lens, or at the lens equator, or in the anterior vitreous, with or without retinal detachment.

IV. Remains of the hyaloid system.

"These four clinical types are not necessarily sharply demarcated but may merge. Type I may change into type 11, or there may be type I in one eye and type 11 in the fellow eye. Otherwise one type cannot go over into another type.”

From the clinical and pathologic findings it would seem "that the basic lesion is a persistence in part or in toto of the primary vitreous with or without hyperplasia and with or without secondary changes consequent to hemorrhage, opening of the lens capsule, and glaucoma.”


1596


BIOMICROSCOPY OF THE EYE


Persistent adherence of the primary vitreous to the retina at the time when the secondar)'’ vitreous forms may lead to retinal separation.


Fig. 488. Free!}’ floating q-stlike body in the anterior vitreous. Noninflammatory vitreous opacity. Female, 28 years of age, vision 0.7. Opacity was seen ophthalmoscopically. It had very little motility and was close to posterior lens capsule. Lens was normal. Hyaloid vitreous was of appreciable optical densit)’, with fine oblique striations. There were several tracts of low luminosity, some of which converge toward the larger intense opacity. The opacity was situated below the arcuate line M'hich is not shown. (After Kobj'.)


At the October, 1948, session of the American Academy of Ophthalmology and Otolaryngology William C. Owens and Ella M. U. Owens presented an interesting study on retrolental fibroplasia in premature infants observed in routine examinations in the Johns Hopkins Hospital. During this study they observed the onset, course, and development of the final picture of retrolental fibroplasia. None of the infants they observed had retrolental fibroplasia at birth. The disease was not related to persistence of the hyaloid system. Early postnatal examinations of the eyes revealed normal fundi. The earliest change observed was the formation of progressive, angiomatous dilations of the retinal vessels, followed by the development of extensive, grayish retinal edema and detachment. The vitreous became cloudy. The retrolental membrane was formed


B

Fig. 489. A. Cystic deformation of hyaloid artery. Eight-year-old child. Pearlikc deformity of hyaloid artery. V. 0.6. Pearhke remnant inserted on the posterior lens capsule by a network of vessels. No arcuate line. Hyaloid vitreous is dark, with faintly visible striations. Anterior band of definitive vitreous is clearly seen with whitish lozenge-like forms separated by darker spaces. The same is repeated deeper but less dearly defined and less luminous. Two years later the pearhke remnant seemed smaller. (Modified after Koby.) B. Cyst; detached hyaloid corpuscle. A cystlike opacity of the vitreous - possibly a detached hyaloid corpuscle. Radiating fibers are probably remains of vessels. Small dark band extending upwards was reddish brown in color. This may be blood in the vessel.


1397


139S


BIOMICROSCOPY OF THE EYE


by the extension across the retrolental space of fusing peripheral portions of the swollen, grayish retinal detachments. The vessels in the retrolental membrane had their origin from retinal vessels and not from vessels associated with the embryonic vascular sheath of the lens. In most cases the active stage of the disease subsided gradually. In some eyes the activity subsided before a complete membrane was formed behind the lens. Usually in these eyes bands simulating retinal folds extended through the vitreous to localized areas of retinal detachment. Newly formed vessels arising from the retina were visible in the folds. From their observations on the course of the disease they have been led to the conclusion that important and as yet unknown etiologic factors must be at work during the postnatal life of the infant. They felt that further work should be directed toward a study of the factors operative during the postnatal life of these infants.

Congenital Vitreous Cysts. Tansley (1899) first reported a case of vitreous cyst. Since then others have been described, apparently of noninflammatory or nonparasitic origin. Some attributed their origin to the ciliary processes. Troncoso (1903)'’^° reported a case in a young girl in whom an oval pigmented semitransparent cyst was seen in the anterior layers of the vitreous. Pigmentation of the surface of a cyst may be a secondary phenomenon and does not justify in itself the assumption that the cyst is of uveal derivation. Recently several cases of Autreous cysts (attached to the posterior lens capsule or freely floating in the anterior vitreous) have been examined biomicroscopically. According to the observations of Lampert and Koby, it appears that freely floating cysts can be derived from the hyaloid artery, even if no evidence of abnormal persistence of the vessel is found (Fig. 488). In one of Koby’s cases, a whitish pearshaped cyst was located at the insertion of the hyaloid artery. The vitreous was normal (Fig. 489 A). In another a pigmented cyst was seen attached to the posterior lens capsule above the insertion of the hyaloid artery, 2 mm. nasal to the posterior pole. The hyaloid vestige hung down behind the capsule undisturbed. Fie considered that the


THE VITREOUS ^399

cyst had detached itself from the vestige. Figure 489 B illustrates another form which I observed deeper in the vitreous.

Practically all the cysts described were monocular. Litinsky




Fig, 490. Cyst of the vitreous, a. Right eye. Cyst of the vitreous cavity. J, B., age 54. Retinitis pigmentosa, b. Left eye. Cyst of the vitreous cavity, in the same patient. Retinitis pigmentosa, c. Ophthalmoscopic view of the above q’sts (Perera).

(1931)^® and Perera (1936)'^®" have described bilateral cysts in retinitis pigmentosa.

In Litinsky’s case there were bilateral slightly mobile spherical formations which, with the biomicroscope, had a reddish reflex. They were suspended by fine filaments which lost themselves toward


1400


BIOMICROSCOPY OF THE EYE


the region of the ora serrata. In Perera’s case, there was a cyst in each eye associated with pigmentary degeneration of the retina (Fig. 490).

Perera states: "Behind the left lens, floating freely in fluid vitreous, was a large 3'^eliowish gr^y globular translucent structure, measuring from 3 to 4 mm. in diameter. Its upper pole was elongated and somewhat indented. The surface of this cyst was smooth, glistening and avascular and contained no pigment. No strands connecting the body with other intra-ocular structures could be identified. On elevation of the eye, the cyst floated up or 'bounced’ into the optical and visual axes, obstructing the fundus reflex viewed through the pupil. When the eye was motionless, the cyst sank to the dependent portion of the vitreous cavity.

"The interior of the right eye revealed a similar but smaller cyst, which was somewhat oval.

"The patient was aware of a momentary blurring of vision when elevating his eye.

"During six months of observation, there was no change in the appearance or size of the cysts.”


32 Biomicroscopy of Vitreous Opacities

General Considerations

In reviewing the older or prebiomlcroscoplc conceptions of vitreous opacities Roemer (1906) divided them into four groups: (i) physiologic muscae volitantes, (2) dustlike elements in the vitreous, (3) filaments and flocculations, and (4) membranes. The latter three may be seen ophthalmoscopically.

Muscae volitantes are those which cannot be perceived with the ophthalmoscope but only b)^ the patient himself. Possibl)’’ they are incorrectly termed "phj^siologic,” since in the light of present knowledge it is felt that they may be associated with pathologic (degenerative or abiotrophic) intra-ocular alterations. The dustlike elements are just visible with the ophthalmoscope especially if a plane mirror and a convex lens is employed (mirror loupe). In this way they can be made to project shadows and with movements of the eyeball to show the characteristic floating or oscillatory motions. The larger filaments, flocculations, and membranes are seen more easil3\ The farther forward the opacities are, the less the}'^ are able to project shadows, and hence they disturb the patient less. Those located deep cast shadows posteriorly upon the retina and consequently are more annoying. This probably accounts for the subjective improvement frequently noted by the patient, i.e., when deeper opacities make their way more anteriorly.

Ophthalmoscopically, it is permissible to assume that the vitreous is altered only when opacities are seen. Against the red glow of the fundus, the vitreous appears optically empty. As the illumination with the ophthalmoscope affords a means of illumination comparable only to transillumination or diaphanoscopy, opacities of suf 1401


1402


BIOMICROSCOPY OF THE EYE


ficient density will appear black or if crystalline, yellowish (Plate LXXX, figs, 6, 7, 8 ) . Accordingly, with this method it is possible to see alterations only when thej'^ become well advanced.

AXfith the focal beam of the biomicroscope the tyndall effect discloses any altered homogeneity or disarrangement of the fibrillae or lamellae forming the vitreous structure. These changes can occur with aging or in myopia. Although these alterations cannot be visualized ophthalmoscopically, from the standpoint of biomicroscopy they must be considered as opacities. The exact degree of density required to cause a biomicroscopically visible alteration to become apparent as an opacity with the ophthalmoscope is not known.

With progressive derangement or degeneration of its framework relatively dark spaces or lacunae form (liquefaction ?)."' (See Fig. 491.) Breakdown, agglutination, or condensation of fibrillae (microfibrillary degeneration) probabl) in the beginning results in the formation of muscae volitantes and eventually, when the formations are large and sufficiently dense, form the so-called floating opacities which can be detected with the ophthalmoscope (Fig. 492). Regarding the membranous types of opacities, it must be remembered that those more or less fixed in the axial regions may be congenital rests, i.e., related to the hyaloid system.

In addition to derangement of the framework and the formation


The existence of liquefaction (synchisis) of the vitreous was assumed originally because of the apparent free movement of visible opacities within it. Ophthalmoscopically it produces no detectable signs. Since freely floating opacities were seen in many conditions (myopia, scnilit}-, trauma, and inflammatory' states) it was held that liquefaction had occurred. As Koby pointed out certain writers on the one hand state that liquefaction is preceded by the formation of opacities and on the other that even a very' liquefied vitreous can remain very transparent; that in the end one can only recognize liquefaction by the presence of highly mobile opacities. At best this leaves us on very' uncertain ground. The physicochemical basis of this change is thought to be one of dehydration of the vitreous micellae, resulting in a condition in which absorbed intra-ocular fluid (water.^) became separated from them. According to Duke-Elder,^^^ "It is due to a conversion of colloidal gel into a sol and is usually associated with development of ophthalmoscopically visible opacities formed by the colloidal micellae which aggregate together in dustlike particles, strands or membranes.” In this case clear spaces (water) should be found between the remaining distorted and agglutinated trabecular structures. Actually with the biomicroscope (arc illumination) no optically clear (dark) spaces - indicating the presence of pockets of fluid are found. Dark spaces are seen with light sources of low intensity' but with the arc lamp (similar to the normal rctrolental space) these spaces become relucent owing to the presence of a trabecular structure. Evidently the physicochemical concept of liquefaction does not exactly coincide with clinical findings. It may be that a relative decrease of viscosity takes place rather than the formation of water-clefts, giving the impression of vitreous liquefaction.


Fig. 492. Senile opacities in the vitreous. Female, age 65. Ophthalmoscopically, floating opacities are seen. Hyaloid vitreous is not sharply differentiated from the definitive vitreous. Some microfibrillary degeneration is seen anteriorly. The whole vitreous is constituted of irregular fibers of variable thickness and lengths. In two places the fibers are condensed so as to form large cottonlike fluffs. Large empty spaces occur near condensations. These condensations are probably muscae volitantes. (After Koby.)


1403


1404


BIOMICROSCOPy OF TPiE EYE


of dark lacunae, biomicroscopically destruction is signalled by a dustlike or flaky cloudiness and frequently by the presence of white, cottony fluffs (Fig. 492). It is interesting to compare the ophthalmoscopic appearance of a vitreous undergoing trabecular degeneration, as indicated by large floating opacities (e.g., in myopia) with what is seen biomicroscopically. The beginner will often be chagrined at his inability to identify a large floater so easily seen with the ophthalmoscope. This results from the difference in illumination employed. In the first place if the opacity is too far back (beyond the anterior one-third) the beam may not be able to reach it. Secondly, even if the opacity is anterior, passage of the beam into the vitreous will reveal a ver)'- nonhomogeneous vitreous with large dark spaces and irregular sinuous and distorted grayish bands (condensed trabecular tissue) and fibrillary degeneration. As one observes this type of tyndall effect, it is usually not possible to identify the exact place or structure which ophthalmoscopically is dense enough to produce a shadow. This brings to mind the difference between the appearances of certain structures in the cornea and lens when viewed by direct focal light and by retro-illumination (a form of diaphanoscopy) (Vol. I). Although we are able to see features within the tyndall phenomenon that are invisible in diffuse or reflected light, unless the differences in index of refraction between the feature and its surroundings are very great, actual contrast within the tyndall beam itself may not be as marked as the contrast obtained by retroillumination (shadow effect) . In lieu of special apparatus designed for this purpose (page 1380) opacities in the deeper parts of the vitreous (even those located near the fundus) may be seen with the plane mirror and loupe (indirect ophthalmoscopy) especially if the light source is intense. These may escape observation with the ordinary electric ophthalmoscope.

Increases in relucency result when a difference occurs in the index of refraction between the fluid of the vitreous and the framework. Normally these indices are practically the same. It should be emphasized that these changes ordinarily are not seen with the ophthalmoscope unless they are pronounced, and that they result from


1405


BIOMICROSCOPY OF VITREOUS OPACITIES

changes endogenous to the vitreous structure, in other words, not from cellular infiltration, e.g., blood cells, fibrin, or uveal pigment. Cellular infiltration (exogenous) in the vitreous forms another class of opacities. When fairly dense, they cause the ophthalmoscopic view of the fundus to be hazy. The deposition of cells may occur without biomicroscopic alteration in the vitreous framework and are capable of absorption. Depending on the gravity of the condition both trabecular destruction and cellular deposition may coexist.

According to biomicroscopic appearances, Koby has listed vitreous changes (opacities) in the order of their seriousness:

1. A diffuse increase in intensity or relucency of the tyndall efiect. This picture is also often produced by trauma and may be ephemeral.

2. Disseminated cellular deposition (tiny dotlike opacities) without any apparent alterations in the framework. They are seen in the uveitides, sympathetic ophthalmia, etc.

3. Alterations of the framework - fibrillary and membranous (lamella) degeneration. This is seen especially in myopia and in senility.

4. Combined forms, where destruction of the framework is associated with cellular deposits of hemorrhagic or inflammatory origin.

The first two can only be observed with the biomicroscope; indications of the second and third may be found ophthalmoscopically

Etiologicall)^ Duke-Elder divides vitreous opacities in tliree classes:

I. Congenital remnants of the hyaloid vascular system

II. Endogenous opacities

A. Protein coagula of the colloid bases of the gel;

B. Crystalline deposits

1. Asteroid bodies

2 . Synchisis scintillans

III. Exogenous opacities

A. Protein coagula - the plasmoid vitreous

B. Exudative cells

C. Blood

D. Tissue cells: epithelial, histocytic, glial

E. Tumor cells

F. Pigment; melanotic and hematogenous

G. Parasites

It should be noted that biomicroscopically, it is not possible to identify or differentiate certain of the opacities listed under exogenous opacities, e.g., tissue cells. In my experience a purely plasmoid vitreous does not occur without exudative cells.


1406


BIOMICROSCOPY OF THE EYE


when they are very marked. The exact appearance of all these alterations, even in conditions of the same etiology, varies from case to case. This is not surprising when one considers the pleomorphic aspects even of the normal vitreous. Individual variations and appearances of opacities will be considered in the chapter on pathologic changes. However, as already indicated in the consideration of cellular deposits in iritis (page 823), caution must be used when judging the color of cells deposited on the vitreous framework.

Senile and Myopic Alterations

The alterations observed in the vitreous biomicroscopically are so similar in senescence and in high degrees of m3mpia that they will be considered together. This similarity was first stressed by Vogt (1924) who pointed out that the vitreous changes in the two conditions, viewed biomicroscopically, often defy differentiation."’ Fundamentally the alterations are of a degenerative nature and are characterized by a disruption of the vitreous framework with resulting production of endogenous opacities (without cellular infiltration). Cellular infiltration results from inflammatory and hemorrhagic processes, and hence its presence or absence is valuable in differential diagnosis.

The concept of liquefaction (based on the presence of floating opacities and “dark” spaces) so often stressed in these forms of degeneration is, as alread}" indicated, of uncertain validity (page 1402) . Even in such cases as synchisis scintillans in which fluidity is regarded as a principal change, the biomicroscope may reveal little if any change in consistency. Hence, although one can conceive of a relative loss in consistency the expression “liquefaction” should be employed with reserve.

In old age and in myopia (depending on the degree and progressiveness) the normal, somewhat regular, arrangement of fibrillae and lamellae is lost (Fig. 491). Condensations in the disrupted vitre ' Vogt struck a parallel between the vitreous alterations in myopia and senility to the degenerative changes occurring in the fundus in these same conditions (circumpapillaryfoveal and peripheral degeneration). In both, the changes may occur abiotrophically in the young (prcsenilc) as well as in older individuals.


Fig. 493. Senile vitreous alterations. “Skein of wool" type of changes. Note twisting of fibrillae and condensations caused by agglutinations of fibers or thickenings at the places where they cross one another.


Fig. 494. Vitreous in myopia. Female, age 34, - 20 D. Ophthalmoscopically the vitreous appears transparent. With the biomicroscope the retrolental space is dark and there is no clear demarcation between the hyaloid and the definitive vitreous. Anterior parts of the vitreous are fibrillar with nodular condensations. Deeper there are structures suggestive of pseudomembranes. The nodular-like white condensations may be the rudiments of microscopic opacities. (After Koby.)


1407


1408


BIOMICROSCOPY OF THE EYE


ous framework account for the vitreous opacities seen ophthalmoscopically (Fig. 492). In the presence of numerous condensations usually seen in the tyndall beam in these conditions, there is not always sufficient difference in density to identify any particular one with the opacity seen ophthalmoscopically. No correlation is found between changes in the vitreous and those in the lens in senility. Marked senile and myopic alterations in the vitreous may occur in the presence of a clear lens. After cataract extraction the changes in the vitreous can be quite minimal.

In the early stages, the vitreous may not exhibit any marked increase in relucency in spite of the disturbance in its architecture. However, with increases in condensation one does get the impression of loss of transparency as evidenced by a more pronounced tyndall effect. Such condensations occur in places where parts of lamellae or fibrillae become twisted or knotted together to form a “skein of wool” or dustlike opacification (Fig. 493).

The so-called “retrolental space” (primary vitreous) may gradually become occupied by distorted scaffolding so that finally larger irregular accumulations approach the posterior surface of the lens. It should be noted that there ma) be differences in behavior between the hyaloid and definitive vitreous and also within the definitive vitreous itself. This gives the impression of ill-defined successive zones within the tyndall beam. For example, in high degrees of myopia even in comparatively young individuals (20 to 40 years of age) one may first see with ordinary illumination that the retrolental space is still relatively dark (Fig. 494). Bordering this there may be a zone occupied by filaments of irregular caliber. Many seem to run in an irregular way but in the main the)'^ tend to hang vertically. Focusing a little deeper one gradually comes to an area occupied by diaphanous veil-like membranes of varying density. These veils seem to be suspended in a darker substrate. But with stronger light sources (arc) it will be observed that this dark substrate in turn becomes more relucent owing to the presence of formations not hitherto seen. In places, an irregular fibrillation may be found on these veils or pseudo-membranes (microfibrillary degeneration). In the depths as far as one can see, the appearance is the same but the veils tend to


BIOMICROSCOPY OF VITREOUS OPACITIES 1409

become more irregukr end wrinkled. With movements of the eyeball all these formations are suddenly set in motion, causing momentary changes in their relations and aspects. In some cases, the


Fig. 495. ^^icrofibrillary clegener.ntion seen in a patient aged 80.


formation of veils may not be so marked in which case one gets the impression of a less distinct tyndall effect. In these cases, large, relatively dark spaces (especiall)'^ in myopia) are enclosed by irregularlycoursing fibrillae. Occasionally as part of them there may be cottony or flakelike opacities - evidently condensation products. Mixed types may occur in which a veil may be seen coursing sinuously between fibrillae. Or the entire vitreous from the posterior surface of the lens may be occupied by veils of marked relucency so that no stratification can be observed. Evidences of microfibrillar)'" degeneration may be seen in the deeper parts, in the form of short irregular lines-’' (Fig. 49)). This type, of fibrillary degeneration may also


In a case of a patient aged 61 years, having senile lens changes, Koby described three zones in the vitreous tyndall effect. In the first, just behind the lens capsule it was just possible to make out oblique striations, especially marked below. The second zone contained filaments going in all directions showing white nodes. The third zone contained fine short, broken filaments, in the form of commas and corkscrews of varying luminosity (microfibrillary degeneration) (Fig. 496).


1410


BIOMICROSCOPY OF THE EYE


occur in the hyaloid vitreous in myopia in which the entire retrolental space is filled with short curved fragments resembling commas or corkscrews (Fig. 497 A) . In order to see such delicate changes a


1 2 3


Fig. 496. Senile vitreous. Female, aged 61. Senile changes in the posterior cortex of the lens. Ophthalmoscopically the vitreous was negative. With the biomicroscope three different zones can be seen in the vitreous: i, area of faintly marked oblique streaks below; 2, dark space containing long filaments, many having fine thickenings; 3, zone of microfibrillary degeneration, with curled fibrils. This last zone appears dusty. (After Koby.)

high degree of illumination and magnification as well as a certain degree of dark adaptation are required.

Koby has described an inconstant change, senile "peppering” of the vitreous which when present is characteristic. "It takes the form of minute white irregularities on the broken strands, giving them an appearance of having been sprinkled with fine sugar. They appear to be formed also on the vestigial vessels, which are less easily differentiated from the fibrinous strands than in youth.” Ordinarily the comparatively larger and whiter vascular filaments because of their regularity will not be confused easily with trabecular fibrillae (Fig. 497 B).

DETACHMENT OF THE VITREOUS (SENILE AND MYOPIC)

Since the middle of the last century, there has been considerable dispute as to whether or not posterior detachments of the vitreous


Fig. 497. A. Myopic alterations in the vitreous. Female, aged 51, - 17 D. Ophthalmoscopically the vitreous shows a high degree of heterogeneity with pseudomembranous-like opacity. The hyaloid vitreous shows microfibrillary degeneration with many fine filaments of low luminosity, sprinkled in places with fine dots. Deeper there are pseudomembranes running obliquely, anastomosing and enclosing dark spaces. A fine striation is seen on the pseudomembranes. B. Senile peppering of the vitreous.

1411


1412


BIOMICROSCOPY OF THE EYE


seen in histologic preparations are due to artefacts (postmortem and hxational). Lately, according to the findings of Samuels (1930)^”^ and von Sallniann (193 - the latter using "nonshrinking” fixa tives - it would seem that man^ such detachments are actual. Clinically the ophthalmoscopic finding in myopia and senility of a delicate membrane hovering in the deeper parts of the vitreous and distinguished by a prepapillary hole (corresponding to the optic disk - area of Martegiani) caused several investigators (Briere, 1875; Galezowski, 1877; and especially Weiss, 1885 to suspect that this represented a separation of the posterior limiting layer of the vitreous.'”' The edges of the opening are usually somewhat cloudy so that looking through it the fundus appears clearer, as if it were seen through a window. In several of the earlier reports, the investigators were uncertain whether the^'^ were dealing with fenestrated vitreous membranes, congenital anomalies (rests of Cloquet’s canal) , or with an actual detachment of the posterior limiting layer of the vitreous. Later Kraupa (1914)"^® revived interest in this subject and affirmed Weiss’s contention that, clinically, this picture signified a posterior detachment of the vitreous. It should be emphasized that not all vitreous opacities are derived from holes or tears of the posterior limiting layer. As pointed out previously, most of them are the result of disruption of the intravitreous framework.

More recently, Pillat,"^" Comberg, Vogt, Lindner, Sallmann and Regen, and Kleefeldf showed that sudden detachment of the vitreous, formerly overlooked, is a very common occurrence in myopia and in senility. It may also be a sequelae of pathologic states. Apparently the strength of attachment of the posterior limiting laj'cr of the vitreous in the area about the papilla is even less than that of the vitreous base (ora serrata). Vogt considered detachment of the vitreous and the resultant ring formation as characteristic of degeneration of the posterior parts of the eye in myopia and in

Elschnii;, Snlzmann .ind \V.\qncr have contended that the prepapillary ring substratum consists of glial tissue in part as evidenced by histologic studies. This view is not inconceivable considering the embryonic relationships of Bergmeister's papilla.

t Kleefeld employed modern techniques: binocular ophthalmoscope, biomicroscope with mirror and contact lens, modified Zamenhoff apparatus.


1413


BIOIvIICROSCOPY OF VITREOUS OPACITIES

senility. Thus, it could belong to the group of chnnges commonly seen in these conditions, e.g., circumpapillary atrophy, equatorial and macular degeneration of retina and choroid, etc.

The detachment usually occurs suddenly, the patient experiencing photopsia (flashes, sparks, etc.). This may last only for a few days and, if minimal, may not be reported or be considered alarming by him. It generally is followed by blurring of vision. This, if slight, may also pass unnoticed by the patient. Others frightened by these symptoms will seek advice. Ophthalmologists not conversant with this condition, after finding no evidence of recent changes in the fundus, have erroneously diagnosed it as vitreous hemorrhage in the old or as a circulatory disturbance in myopes. With the simple ophthalmoscope or better with the plane mirror and a lens of plus 6 to plus 9 diopters, the mobile prepapillary ring may be observed clearly.'*' In its most obvious form, the ring is located in front of the disk, its periphery being somewhat opalescent (Plate LXXX, figs. 1-5). The remainder of the detached membrane may not be clearly apparent, its presence being indicated by a veiling of the fundal reflex. Radial projections are often seen extending from the margins of the ring (expression of the radial structure of the posterior limiting membrane ?) . Movements of the ophthalmoscope will alternately cause the ring to become luminous or dark (shadow effect) . With time the appearance and location of the ring changes. As it comes forward, it becomes more mobile and tends to lose its circular character. Also the patient, entoptically, becomes less aware of it. If the ring assumes a sagittal or horizontal position, the lumen may not be apparent and only its edge (appearing as a sinuous line) can be projected. In this case it may become difficult to differentiate the tear from ordinary endogenous intravitreous opacities. In addition to the circumpapillary tear and detachment, holes in other areas of the posterior limiting membranes may occur. These may not be prepapillary and frequently are multiple. This possibly occurs as a


••'Both Kraupa and Vogt recommend the employment of strong sources of illumination with the indirect method of ophthalmoscopy- the arc lamp or red-free illumination (direct current) gives the best results. '


PLATE LXXX


Fig. I. Det.nchment of the posterior limiting surface of the vitreous. Ophthalmoscopic view.

Fig. 2. Same case as in Figure i. Showing several holes and surrounding opacification.

Fig. 3. Detail of the hole in the posterior limiting layer of the vitreous.

Fig. 4. Fenestrated type of detached limiting layer of the vitreous.

Fig. j. Detachment of the posterior limiting surface of the vitreous. Showing details at the edges of the holes.

Figs. 6 , 7 and 8. Various forms of vitreous opacities as seen ophthalmoscopically.


1414



biomicroscopy of vitreous opacities H17

result of more extensive retinal and choroidal changes. Vogt noted it in a case of choroiditis jtixlapapillaiis (Jensen).

For examination of the posterior vitreous, Lindner used a modi


Fig. 498. Detacliment of tlic posterior limiting layer of the vitreous. Observation by means of contact lens showing, left to right, retina, posterior limiting layer of the vitreous, lens and the cornea. (After Vogt.)


fied Koeppe contact lens. Kleefeld modified the Zamenhof ophthalmoscope by inserting a metal ring in its system (page 1383). Lindner,"' Sallmann, Goldmann and Rieger, by means of the contact glass, demonstrated with the optic section preretinal detachments of the vitreous. Only by means of tyndall effect (narrow beam) is it possible accurately to visualize a membrane as delicate as the posterior limiting layer of the vitreous. However, in attempting to illuminate the deeper vitreous by any method, the red reflex from the fundus (diffuse illumination) always causes some interference (Fig. 49S).

In many cases in which detachment of the vitreous is suspected, it is possible even without a contact lens later to demonstrate a superiorly detached posterior limiting membrane. It is preferable to observe the passage of the beam with the unaided eye (macroscopi

Lately Lindner has recommended the Hruby glass (see page 1386).

1418


BIOMICROSCOPY OF THE EYE


cally - the method of fentoscopy). In this way, with the lo-cm. illuminating lens and without an)’- other special aids one can follow the vitreous tyndall effect to a depth corresponding to three or four


a- b O- P


Fig. 499. Detachment of the posterior limiting layer of the vitreous. (After Vogt.)


lens thicknesses. It frequently happens that the detached and anteriorly retracted posterior limiting layer falls within the zone illuminated by the beam (Fig. 499). This membrane will be seen as a mobile structure limiting the contained vitreous structure which, owing to gravity (during moments of rest), assumes a dependent position. Above this, a clear (dark) area indicates that it is free of vitreous framework. With slight movements of the eye the limiting membrane and its contained structures beneath it are set in motion causing a change in the relationship between them and the darker (optically free) area above them. With rest the original picture is resumed. At first, for example, the zone a - h \s small and limited to the dorsal part of the vitreous but with progression the retrolental portion O - P may be reduced to a thickness comparable to that of the lens (Fig. 500). The nature of the contents of the relatively dark area behind or above the detached posterior limiting layer and its contained trabecular structure is not known exactly. One should hke to compare it to the postretinal fluid in retinal detachment which is slightly viscid (not like aqueous) . In any event, there is sufficient difference in index of refraction between the detached frame


1419


BIOMICROSCOPY OF VITREOUS OPACITIES

work -containing part and the dark part to cause a significant lack

o£ n'ndall dispersion in the latter.

Comberg. Koby and others have described the rarer anterior de

O- P


tachment of the vitreous especially in trauma or after inflammatory conditions. Many of the investigators considered that detachment of the vitreous was always associated with or at least was a precursor of spontaneous" retinal separation, and hence was the cause of it. The fact that detachment of the posterior lamella of the vitreous occurs so commonly and that in a few reported instances only was it £oliovs*ed by retinal separation, would indicate that no direct causal relationship exists between them. However, an exception to this may be true when instead of a "clean" separation of the posterior limiting layer of the vitreous, tags or strands of vitreous remain attached to the retina. Traction of such strands to a preexisting degenerated retina (see infra) might conceivably start the formation ot a retin.d hole. Biomicroscopically. in spontaneous detachment ot the retina fixed membranes (inflammator\-) have not been tound in the vitreous. Some authors have held that these strands might by contraction detach the retina. There is considerable evidence today that a retinal tear or hole formation is a sine qua non ot spontaneous retinal detachment. Histologic examination (Hansen-K-umell, Sourdille. and lironfeld) in cases of recent detachment


1420


BIOMICROSCOPY OF THE EYE


(after 7 to 60 days) revealed no indication of any inflammatory process. Peripheral chorioretinitic (cystic) degeneration and atrophy was seen in the neighborhood of the tear. Only fresh cases of retinal detachment, i.e., before secondary pre- and postretinal changes have occurred, can histologically give reliable information. Vogt (1934) confirmed this and in addition found in some of his cases, an "uncapped” cyst. In other words, a peripheral retinal cyst in which its surface (facing the vitreous) was partly unhinged. Vitreous framework was adherent to this partly detached cap. According to Vogt retinal (noninflammatory) cystic and atrophic degeneration forms the basis of hole formation and subsequent retinal separation. Clinically, the detached cap of retinal tissues or fragments thereof have been observed floating in the vitreous or adherent to some of its filaments. Evidences of this have been seen ophthalmoscopically, not necessarily coincident with actual retinal separation in every case. The actual hingelike uncapping (hole formation) is a consequence of the swirling about (jactatio corporis vitreii) of an altered vitreous, attachment of which normally is probably firmer in the region of its base at the ora serrata. Vogt’s hypothesis that spontaneous retinal detachment is primarily dependent on retinal degeneration and only secondarily on vitreous degeneration could also be valid in the nonmyopic cases or senile cases. Myopic lengthening of the globe is not contributory by itself to retinal separation, as has hitherto been thought by many writers; actually, like senile degeneration, it merely contributes to eventual separation. The same principle may obtain in postoperative detachment of the retina following discission or extraction of secondary cataracts (membranes) , which may be due to traction upon a susceptible retina transmitted by adherent vitreous strands. In older persons, detachment of the retina may be accompanied or preceded by a sudden and massive vitreous hemorrhage. This may prevent ophthalmoscopic visualization of the fundus at the time the patient is first seen. After a week or 10 days absorption of the blood permits the detection of a retinal separation. In 3 of my cases recently observed, the retinal separation occurred in the region of the upper temporal quadrant. All had tears. In one


1421


BIOMICROSCOPY OF VITREOUS OPACITIES

case the tear was found directly in the path of a small retinal vein, giving the impression that it had been torn across. All three were

cured by operation.


Fig. 5QI. Asteroid hyalosis.


Fig, 502. Asteroid hyalosis. Note pseudomembranes. Male, age 71, vision 0.5. Ophthalmoscopically, besides brilliant opacities, pseudomembranes appeared like spider webs. With a biomicroscope the whole of the vitreous showed round brilliant opacities which extended nearly up to the posterior lens capsule. There were many filamentous and membranous formations resembling spider webs. These were encrusted with round opacities of varying sizes - all very luminous. The lens shows early signs of posterior cortical cataract. (After Koby.)


Synchysis Scintillans and Asteroid Hyalosis

Considering the crystalline nature of the deposits in synchysis scintillans and the calcium soap composition of those in asteroid "hyalitis,” it would appear that, strictly speaking, their endogenous


1422


BIOMICROSCOPY OF THE EYE


nature is open to question. However, in view of the fact that these changes may appear in the absence of any other clinically demonstrable deteriorations in the eye most authors have preferred to classify them as strictly degenerative changes in the same sense that myopic and senile changes are so classified.

Asteroid Bodies ( [Asteroid "hyalitis” or hyalosis] ; scintillatio albescens [Benson’s Disease] ) : This unusual type of deposition not uncommonly seen in the older age groups, usually in the seventh and eighth decades, presents a very striking biomicroscopic and ophthalmoscopic picture. In a large proportion monocular involvement is the rule. They do not have any significant pathologic portent. Ophthalmoscopically, in the glow of the reflected light from the fundus asteroid bodies appear yellowish-white, shiny "looking like snowballs or stars in the night sky.” Their shape is spheroidal or oval. They are commonly disseminated throughout the vitreous but also may be seen in localized strands or clumps arranged in columns. With the biomicroscope one is struck by a picture of unexcelled beauty. They appear as matt-white disks, spheroids and ovoids which in some instances gleam brilliantly (Fig. 501). There may be very little disturbance in the vitreous framework. However, at times a slight alteration may be noted in the form of poorly luminous filaments or networks arranged like spider webs and covered with a brilliant dust (Fig. 502). With eyeball movements these bodies oscillate only slightly and quickly return to their original position. This point differentiates them from the more mobile crystalline deposits of synchysis scintillans. As the beam traverses the vitreous, those directly in its path and in clear focus shine brilliantly whereas those to one side appear dimmer and larger because of the effect of diffusion circles (Fig. 503).

It is only recently that the differences between asteroid hyalitis and synchysis scintillans have been stressed (see Vol. I) . Synchysis scintillans although rarer tends to occur in younger individuals and is more often bilateral. In contradistinction to asteroid "hyalitis” the particles in synchysis scintillans, which are crystalline and angular rather than rounded, float about with greater rapidity and


Fig. 503. Asteroid hyalosib. Patient aged 60, vision 0.6. The lens is normal. Note that tlie filaments are of low luminosity. They are of irregular length and caliber. Numerous white and very luminous opacities (round to oval) arranged in places like clusters. Those out of focus seem larger and fainter owing to circles of diffusion. (After Koby.)


Fig. 504. A. Synchysis scintillans. b. Synchysis scintillans in an aphakic eye following severe hemorrhage which occurred five days postoperatively.


1423


1424


BIOMICROSCOPY OF THE EYE


gravitate to the bottom of the degenerated vitreous during rest. According to Duke-Elder, they may be likened to "a shower of glittering golden sovereigns or silvery tinsel-like particles.” "Ophthalmoscopically . . . they present a beautiful and quite characteristic picture as they flash by with a gleam as of burnished gold.” "With the biomicroscope the silvery tinsel-like appearance is mostly seen. This picture is reminiscent of the snowstorm effect created in the old-fashioned paper weights (Fig. 504 A, B) . In synchysis scintillans the beam also reveals considerable disruption of the vitreous framework with the formation of relatively dark empty spaces.

Changes in Inflammation

Similar to the lens, the normal vitreous is avascular, but, unlike it, it is acellular. Hence the effect of inflammation can only be passive and brought about by the surrounding tissues (retina and uvea) . Inflammation in these tissues will induce vitreous changes very early. The term “hyalitis” although apt, is not strictly in accord with the ending "itis” as commonly applied. The suggested term "hyalosis” may be preferable. In the early stages of intraocular inflammation the vitreous is permeated by the outpouring of inflammatory products. Some authors have described an immediate haziness of the vitreous due to a "plasmoid” exudate which increases the tyndall effect. Even at this stage, with sufficiently high magnification and light intensity the tyndall beam will reveal white dots (cells) within the haze. The main differentiation between early inflammatory states and the purely degenerative lesions (myopia, senility) lies in the fact that the former is characterized by an immediate cellular infiltration migrating from the neighboring tissues. In the latter (see above) the changes produced are of an endogenous nature resulting from the degradation of the vitreous colloidal structure. However, as inflammatory processes continue, and bearing in mind the physicochemical instability of the vitreous, the initial cellular infiltration will be followed by destruction of the vitreous framework, with the production of endogenous opacities. In the end this can surpass that seen in the degenerative states.


1425


BIOMICROSCOPY OF VITREOUS OPACITIES

A


i


B

Fig. 505. A. Cells in the vitreous (early sympathetic ophthalmia). B. Keratic piecipitates. Flare in the anterior chamber and deposits on the anterior lens capusle and in the vitreous of the same eye as shown in A.

Among tlie variety of vitreous opacities seen are:

I. Opacities due to cellular infiltration

A. Dust: dotlike in nature which can aggregate into

1. Larger plaques

2 . Comet-shaped and filamentary forms

3. Striae - forming linear, striate, or bandlike configurations

B. Pigment particles


1426


BIOMICROSCOPY OF THE EYE


II. Opacities due to endogenous destruction of the vitreous framework

A. Flocculations - appearing as tufted or nodular condensations

B. Fibrillary or microfibrillary degeneration

C. Pseudomembranous formations


Fig. 506 Unusual condensations of exudates in the vitreous in the case of tuberculous uveitis.


The early changes in the vitreous brought about by inflammatory reactions consist in the deposition of small white dots (cells) (Fig. 505 A). Each cell is seen as a brilliant dot by virtue of its diffusion or diffraction of light but the morphology is indeterminate, so differentiation between the cells is impossible. With increasing deposition the vitreous framework may be delineated more clearly by attachment of the cells to the fibrillae. The appearance and distribution, similar to the condition in the aqueous, does not permit of a specific etiologic diagnosis, nor does any specific disease evolve a characteristic picture. Early in the course of an inflammation, depending on the severity, only a few scattered dots may be found in the retrolental space. These cells can only be seen biomicroscopically. As the inflammation progresses, the cells tend to ag


BIOMICROSCOPY OF VITREOUS OPACITIES 1427

glomerate into larger clumped forms, thus producing plaques - (stellate or comet-shaped opacities or filamentary forms) - (Figs.


Fig. 507. Comet-likc conden.sation.s of exudates in the vitreous in uveitis.


Fig. 508. Deposits attached to the vitreous framework and arranged in linear and striaform

configurations.

506-508). A yellowish tinge may be imparted to these denser collections. These latter may coexist with the early discrete dots.

Arrangement into linear, striaform or banded configurations of dot opacities is seen, frequently resembling a galactic "milky way” (Fig. 508). Such a distribution may be, in part, governed by the


PLATE LXXXI


Fig. I. Postinflammatory pigmentation of the vitreous (after uveitis).

Fig. 2. Same case as shown in Figure i. Illustrating the pigment deposited on the anterior lens capsule.

Fig. 3. Pigment deposits and vitreous changes in a case of detachment of the retina. Early signs of complicated cataract.

Fig. 4. Pigment deposited in the vitreous (sympathetic ophthalmia).

Fig. 5. Pigmentation of the vitreous in retinitis pigmentosa. Complicated cataract.


1428


1431


BIOMICROSCOPY OF VITREOUS OPACITIES

structural lamination of the vitreous. These latter are found mainly in the chronic types of disease. Frequently the disrupted vitreous framework is so heavily dusted with a coating of imperceptible particles that an appearance of opaque veils or pseudomembranes results (see Figs. 496 and 497).

It is the author’s impression that depending upon the nature and intensity of the disease process uveal pigment granules may be discerned very early in acute fulminating attacks or they may appear also as a late manifestation in the chronic forms (Plate LXXXI, fig. I ) . Although the individual dots as such cannot be recognized ophthalmoscopically, when they are numerous and disseminated a reddish hue is imparted to the nervehead while the usually brightred fundus reflex becomes rosy in tint. This optical phenomenon results from a diffraction of the rays of light causing a shift in the spectrum to the warmer side. However, larger aggregates can be made out ophthalmoscopically as blackish or grayish clumps or strands defined against the reddish fundus background. It is only in synchisis scintillans and asteroid hyalitis that the deposits are sufficiently refractile to gleam yellowish or golden in the former, and whitish in the latter.

It should be noted that the transition of exogenous infiltration to the formation of endogenous opacities (resulting from destruction of the vitreous framework) is not sharply demarcated. Rather the latter formations are indicative of intensity and chronicity of the involvement. The endogenous opacities do not differ in appearance from those seen in myopia and senility (page 1406) except that the concomitant associated cellular infiltrations become more extensive. The condensations and pseudomembranes produced as a consequence of alterations of the vitreous structural framework are more mobile than the earlier punctate precipitates. This results from diminution of the vitreous viscosity. This may be evidenced by the formation of relatively dark spaces or clefts seen between the more relucent formations. As Duke-Elder describes it "the picture may be complicated, an abundance of minute white specks, spangles and threads are mingled with large agglutinations like tangled skeins of wool,


Fig. 509. Vitreous deposits. Cellular deposits in the vitreous with early disruption of the

framework. Iridocyclitis.


Fig. 510. Cellular deposits in the vitreous with more advanced disruption of the framework. Right eye; heterochromia syndrome. The iris is discolored. Numerous keratic precipitates present. Vision 0.9. Posterior cortex of the Jens showed a polychromatic luster (irridescence) owing to beginning of cataracta complicata. Anterior parts of the vitreous were dusted over with fine white opacities. Further back a dark space containing vascular remnants is seen. Still deeper are dust)’ pseudomembranes. {After Koby.)


1432


Fig. 511. Cellular deposits in the vitreous with marked rclucency of the disturbed elements of the vitreous framework. Iridocyclitis. Female, aged 20. Probably tuberculous. The posterior capsule of the lens shows a few striaform deposits. The whole of the vitreous structure is accentuated (more relucent) owing to dust adherent to the fibrous type of framework.


Fig. 512. Chronic iridocyclitis. Very extensive infiltration of cells. The vitreous framework is disrupted and owing to a heavy dusting has become opaque, giving the impression of being formed of veils or membranes. Beginning cataracta complicata. Smudged area above the lens opacity is caused by iridescence, the color display exhibiting green, red, and yellow hues.


1433


1434


BIOMICROSCOPY OF THE EYE


broad sinuous bands, wavy membranes, and extremely dense floating clouds, the whole oscillating slightly and swaying across the pupil with movements of the eyes” (Figs. 509, 510, 511). Finally, after a


Fig. 513. Pseudomembranes in the vitreous in chronic uveitis. Anterior separation of the vitreous. Deposits on the vitreous surface almost gives the impression of a reduplication of the stripe of the posterior lens capsule. The vitreous has been altered so that its structure appears to be formed of very luminous whitish pseudomembranes in a fanlike design. The increased relucency of these structures results from a dusting by fine deposits.


protracted iridocyclitis and consequent to the formation of dense white membranes with marked cellular infiltrates the opacification of the vitreous becomes so great that these structures may be seen ophthalmoscopically (Fig. 512). In these cases, as reported by Comberg (1924), an anterior separation of the vitreous from the lens has been noted. This may be indicated by the fact that the anterior surface of the displaced vitreous becomes encrusted heavily with fine whitish deposits (Fig. 513). According to Koby, no characteristic vitreous changes are found in glaucoma. Whereas in optic neuritis (papillitis), in sympathetic ophthalmitis, and at the beginning of uveitides, the tiny opacities are not too numerous. They are innumerable in the choroididites, the chronic uveitides, and the pigmentary retinitides. Generally, they are not seen in the "circinate” or "albuminuric” types of retinitis, the embolizations or thromboses of the retinal vessels nor in the retrobulbar or toxic neuritides.


1435


BIOMICROSCOPY OF VITREOUS OPACITIES

While an association between the appearance of opacities and the etiology of the underlying condition is not possible, certain special conditions deserve separate consideration.


Fig. 514. The vitreous in licterochromic cyditis. Note the star-shaped opacities in the vitreous and the precipitates in the posterior lens capsule. (After Vogt.)

HETEROCHROMIC CYCLITIS

Since the work of Fuchs (1906) this disease has been recognized as a special type of lesion characterized by an unusual combination of a low intensity process leading to iris color changes, absence of synechia, and the presence of posterior corneal precipitates without visual loss, until late development of complicated cataract. A feature which is found frequently in the vitreous is a disseminated dustcloud of dotlike or star-form opacities or white to yellowish plaques. As Vogt (1921) significantly pointed out, it may occur without alteration of the vitreous structural framework (Fig. 514). Precipitates occur also on the posterior lens capsule. Unilaterality of involvement is most frequent and the sequelae are complicated cataract or secondary glaucoma in many instances. In a case described by Koby occurring in a 3 3 -year-old male with blue irides, the left eye contained some diffuse yellowish pigment. The anterior vitreous was studded with very fine white opacities, a dark space containing embryonal vascular remains occurred next and the deeper vitreous was regularly stratified with white opacities of variable size. On the posterior lens capsule whitish deposits were seen.


1436


BIOMICROSCOPY OF THE EYE


SYMPATHETIC OPHTHALMITIS

The vitreous in sympathetic ophthalmitis was studied biomicroscopically by Vogt ( 1921 ) . He held that "occurrence in the aqueous,


Fig. 515. The vitreous in sympathetic ophthalmitis. A case of a young Negro woman who six weeks previously had had an operation (iridenclesis) for chronic simple glaucoma in the other eye. Note the heavy exudate on the posterior lens capsule.

retrolental space, and the vitreous of free-floating particles (whitish, reddish, or brown) often in large quantity’.’ are invariable early phenomena (Fig. 515). In ephemeral reactions of the sympathizing eye (subsiding in a few weeks) whitish and brown lines and opacities (white dots and pigment) of a transitory nature occur. It has also been noted that the opacities were especially numerous in the lower portions of the vitreous. Minute, repeated accurate biomicroscopic examination of the sympathizing eye is a necessity in all suspected cases. Biomicroscopically, it should be pointed out that there are no clear delineations between sympathetic irritation and sympathetic ophthalmitis per se. (See chapter on iris - Sympathetic Ophthalmitis, page 905.)

The insidious onset and the early absence of all signs, except retrolental opacities of a whitish brilliant nature (which when marked may form a carpeting on the posterior lens capsule) are deceptive, as Molotese (i924)'’ has stressed. Deposits on the posterior lens capsule may be fixed or if they are attached (stringlike) by one end, they may be slightly motile. With aggravation of the sympathetic process this disease presents a picture of marked infiltration and endogenous destruction of the vitreous common to all severe and fulminating intra-ocular inflammations.

OPTIC NEURITIS (PAPILLITIS )

It is only in definite inflammation of the optic papilla that one can expect to find vitreous opacities. They are not seen ordinarily in retrobulbar and toxic affections of the optic nerve. Koby has pointed out that in inflammations of the papilla the opacities may emigrate anteriorly via Cloquet’s canal where they can remain localized. The clinical findings, in the beginning, may include a "cloud of opacities in the posterior vitreous.” In later stages of optic neuritis fine deposits of pigment upon the vitreous fibers may be discerned. Koeppe has suggested that inspection of the posterior vitreous (by means of a contact glass) may aid in the differentiation from papilledema by finding these deposits present in the earliest stages.

It has been observed occasionally that the occurrence of cryptogenic vitreous opacities as clouds of fine dots appearing suddenly (sometimes quite intensely) may be associated with ophthalmoscopically invisible foci of the uvea."'

RETINAL DETACHMENT

The vitreous in spontaneous retinal detachment as a rule displays extensive alteration both of the exogenous and endogenous types. Considering the incidence of concurrent myopia and retinal detachment it is to be expected that endogenous vitreous changes might

Duke-Elder has stated that "such a happening is of common and general occurrence but is seen most typically in women of late middle age. . . . The importance of the syndrome IS that it may well form the prelude to a series of similar attacks each involving the disability of further vitreous opacities, or to more serious and widespread uveal inflammation

of a recalcitrant and chronic nature unless the etiology is discovered and combatted in

many cases a task of no small difficulty,”


Fig. 516. A. The vitreous in detachment of the retina. The detachment followed a discission of a delicate secondary membrane. B. Vitreous in the detachment of the retina. Disruption and thickening of the framework. Note the clumps and the attachment of vitreous strands to the posterior lens capsule, c. Veil-like opacity in the vitreous following detachment of the retina. Seen soon after retinal separation. The vitreous in the retrolental area is iibrillous and of low luminosity. The deeper layers are more relucent. Below is an area of microfibrillary degeneration. Above there is an ill-defined curved opacity (resembling a dense veil with its conve.vity pointed downwards) extending posteriorally into the deeper parts of the vitreous. D. The vitreous in detachment of the retina. High-grade myopia. Deposits on the posterior lens capsule. The vitreous shows presence of translucent cylindrical or pointed tubes or conis of irregular caliber, crisscrossing one another, with brownish and whitish deposits. Between them are numerous large round opacities, (After Koby.)



BIOMICROSCOPY OF VITREOUS OPACITIES 1439

occur. This is demonstrable by condensation of the vitreous framework; thickening of the fibrillae interposed with dark spaces. Progressively suck changes lead to the formation of swirling pseudomembranes intermingled with thready fibrillae associated with more delicate microfibrillary degeneration (Fig. 5 16 A, B, C, D) . In addition to these mobile opacities formed by the aforementioned condensations, whitish-brown and reddish clumps or disks (which may or may not be pigmented) are seen. In older cases these may appear as brilliant gilded platelets. Opacities containing or consisting of pigment are characteristic of cases of retinal detachment sometimes appearing in the form of clusters or as isolated dots (Plate LXXXI, fig. 3 ) . Koby has described a special alteration of the vitreous structure in the form of translucent, elongated cylindroids, the ends of which ma}^ be pointed, scattered and anastomosed irregularly. An impression is gained that they may be constituted by the curling of a fine membrane. On these cylindroids, one may be able to detect a fine whitish strlation or occasional whitish deposits. The complexity of the picture is further added to by the sequelae of acute inflammatory processes (iritis) so common after retinal separation (Fig. 516 D).

RETINITIS PIGMENTOSA (TAPETO-RETINAL DEGENERATION)

As a widespread primary pigmentary retinal degeneration with tapeto-retlnal atrophy, this disease presents a characteristic clinical picture, which inexorably progresses to great loss of visual function. It may well be that the degenerative process tends to elaboration of toxic substances into the vitreous. Such toxins may also play a role in the ultimate development of a posterior polar complicated cataract commonly seen in this condition. The degree of vitreous change varies from case to case and usually is a later manifestation. Vogt described a case of a 39-year-old man in which grayish-white ropelike strands occurred in the lower vitreous with discrete white dots deposited on the vitreous framework. Also white cloudy cottonlike agglutinations of the structure were seen as if the latter was


1440


BIOMICROSCOPY OF THE EYE


filled with a fine white dust. Pigment in the form of dust or dots may be found in the vitreous or on the posterior lens capsule (Plate LXXXI, fig. 5)


Fig. 517 Melanosarcoma protruding into the vitreous just behind the lens. Note vessels overlying tumor mass The vitreous framework is disturbed and shows infiltration with white and pigmented cells.


Tumors Affecting the Vitreous

GLIOMA retinae (RETINOBLASTOMA)

In Vogt’s cases, in the first of which the tumor had extended anteriorly within the vitreous almost to the lens, rounded, coarse, white and brown precipitates could be seen on the surface of the tumor and the posterior lens capsule. In the second instance, the vitreous was filled with freely floating dustlike scintillating deposits. Similar ones were seen adherent to the posterior lens capsule. Vogt attributed the colored scintillation to fine cholesterol crystalline deposits. Considered of great diagnostic importance is the finding of detached clumps of tumor cells in the vitreous. Ophthalmoscopically these may appear as large floating opacities.


BIOMICROSCOPY OF VITREOUS OPACITIES


1441


MHLANOSARCOMA

In certain cases of melanosarcoma, particularly those of the ciliary body, the protrusion of the tumor may be so far forward that the dark brownish surface falls within the scope of the beam (Fig. 517). When this occurs, it is often possible to make out certain details pf the surface of the mass. Sometimes the malignant tumor in the ciliary body may compress the vitreous against the lens. Occasionally in such cases some brownish points may be seen in the area occupied b)’’ the compressed vitreous. It is not possible definitely to state whether these arc metastatic tumor cells. In other cases the tumor may actually indent the lens itself.

In a personal observation a delicate, fuzzy, whitish layer was seen to cover the dark brown pigmented tumor mass. This may have been degenerated retinal tissue. Also in many cases the retinal vessels may be seen coursing over the tumor. Disruption of the vitreous frame with varying amounts of cellular infiltration, both white and pigmented, is common (Fig. 517).

Traumatic Injuries to the Vitreous

From the viewpoint of the biomicroscopist injuries to the eye, whether due to external violence (contusions, or perforations with or without presence of foreign bodies) or operative interference may produce the following changes in the vitreous:

I. Increase in rcluccncy of the tyndall beam

A. Plasmoid vitreous

B. Hemori'hage

1. On posterior lens capsule (retrolental space,

Berger)

2. Intravitreous

a. In Clouquet’s canal

b. Laminated or parallel bands or striae

c. Disseminated

C. Pigment (uveal)

D. White cellular elements

E. Lenticular or capsular debris or residua


1442


BIOMICROSCOPY OF THE EYE


11. Disruptions of the vitreous framework

A. Traction bands

B. External prolapse

C. Internal prolapse or herniation

D. Kerato-vitreous adhesions or synechiae. III. Visible foreign bodies


Fig. 518. Stariike figures in the vitreous following trauma (nonperforating injury). These figures are the result of the deposition of formed elements (white cells) on the fibers of the vitreous framework.

INCREASE IN RELUCENCY OF THE TYNDALL PHENOMENON

One of the most elusive reactions in the vitreous, seen especially after contusion, is an increase in relucency of the focal beam. This is the result of a plasmoid effusion. It may be the only sign following a contusion and is demonstrable only biomicroscopically. However,


Fig. 519. Incrcnstd luccncy (if (he xitrtoiis lyml.ill. Aph.ikin; cyclitis Note flare and cells in the aqueous. Tlie focal lie.iin is scr) reluccnt as it p.isses throujeh the vitreous owing to plasmoid effusion and cells. Tiie sitreous stratification is presersed. (After Koby.)



PLATE LXXXII


Fig. I. Old hemorrhages in the vitreous. Blood cells deposited on the vitreous framework. Posterior complicated cataract.

Fig. 2. Flemorrhage in the vitreous. Fresh blood seen above outlined by the upper border of the hyaloid. Below the older blood cells are yellow in color.

Fig. 3. Pigment deposits in the vitreous and on the posterior lens capsule. Uveitis.

Fig. 4. Hemorrhage in the vitreous observed one year later. Note the lack of color in the cells.

Fig. 5 . Hemorrhage in the vitreous. Fresh blood in the vitreous and on the posterior lens capsule. (After Koby.)

Fig. 6 . Blood cells outlining prolapsed vitreous into the anterior chamber. Hemorrhage into the anterior chamber occurred four days after an intracapsular cataract extraction.


1444



BIOMICROSCOPy OF VITREOUS OPACITIES


1447


when it is marked, its presence may be suspected ophthalmoscopically by a careful observer, owing to slight blurring of the fundus reflex and details. Depending on its degree, such a change may be ephemeral; but marked increase of formed elements gives rise to residua which may remain for long periods (Fig. 518). As described previously, increase in the lyndall cflect is seen best by observing the passage of the focal beam into the vitreous with the unaided eye (fentoscopy) . This increase in the tyndall effect is produced by a combination of formed and unformed elements, probably fibrin coagulants intermixed with whole or fragmented cells, or the increased light dispersion may be caused wholly by liberated pigmented debris (uveal) (Fig. 519). Very often in contusions the development of a plasmoid aqueous (see Vol. I, page 5 88) maj'^ hinder observation of the vitreous because of a screening effect.

Houorrlm^c

Hemorrhage into the vitreous is probably the commonest finding of all after injury (Fig. j2o). It may be seen adherent to the posterior lens capsule, in the retrolental area or within the definitive vitreous substance (intravitreous) . It should be kept in mind that hemorrhage may be the consequence of pathologic processes posteriorly and from the biomicroscopic appearance alone differentiation may not be possible. In this connection Ascher (1920)'’'” pointed out that in cases of trauma the hemorrhages that come from the ciliary body tend to diffuse into the anterior vitreous and especially upon the posterior lens capsule.

On the posterior lens capsule the hemorrhagic deposits are bright red in color with the focal beam, forming sinuous bands, which may be delineated inferiorly as crescentic curves by the ligamentum hyaloidea-capsulare (Weigert). This color is best seen with the unaided eye. Depending on the amount, distribution and duration, the picture of blood on the posterior lens capsule varies. It may appear also as bright-red plaques, or as pointed out on page 1219, distributed as annular rings, perihyaloidian clumps, within the arcuate line, or disseminated (Koby). (See Plate LXXXII, fig. 5.) According to its


1448


BIOMICROSCOPy OF THE EYE


duration, the blood depositions may change in character and color owing to laking and disintegration. In such instances the color of the deposits on the posterior lens capsule may change from bronze


Fig. 521. Striate deposits on the posterior lens capsule following trauma (contusion). Young man injured one daj' previously by a cut wire which struck the center of the cornea. Posterior surface of the lens shows numerous deposits in the form of irregular striae, giving the appearance of moss. The reiucency (tyndall) of the vitreous is increased. Note rests of the hyaloid artery (corkscrew-like filament) attached to the posterior lens capsule. (After Koby.)


(similar in appearance to Vossius’ ring) to yellow and eventually to a whitish glistening dust. Sometimes overlying the cellular deposit on the posterior lens capsule, white cloudy epicapsular depositions (fibrinous residua of blood) are discerned (Fig. 521). In flat depositions, fixation of the blood elements to the posterior lens capsule occurs (Plate LXXXII, fig. 5). According to its quantity, the deposit bulges posteriorly into the retrolental space like a cap thinner peripherally than centrally, and may appear to move slightly with eye or head movements. Evidences of hemorrhage on the posterior lens capsule and within the retrolental space ma) remain for extensive periods.

hifravifreoiis hemorrhage. Hemorrhages within the vitreous proper present varying appearances according to the individual circumstances concerned. By the time the case is presented for inspection or biomicroscopic examination is feasible, hemorrhage into the vitreous may be an outstanding feature. The blood cells may be


BIOMICROSCOPY OF VITREOUS OPACITIES


1449


diffused and disseminated upon the vitreous framework or it will be found regionalized, occupying certain areas, appearing as irregular localized collections (Fig. 520). In other cases, the deposition may be arranged as tensed bands separated from one another by dark intervals (lamination). After perforations, parallel bands of this nature, consisting partly of blood cells and stretched vitreous framework, may be seen extending rectilinearly toward the wound and also may be marked on the opposite side. In a case noted by the author an adherent band covered with blood cells stretched from the lower part of the posterior lens capsule backward into the disorganized vitreous. The retrolental space was obliterated,

Intravitreous collections apparently confined to or outlining Cloquet’s canal (or distending or sacculating it) are seen often. Histologically there is confirmation of this possibility not only with hemorrhage but also with inflammatory products (Fuchs; Samuels). Koby cites Hoffman (1926) *"“ who reported the case of a lad of 8 years; two months following contusion, the globe revealed a dark tunnel outlined by reddish points (the anterior extremity of Cloquet’s canal) immediately behind the posterior pole of the lens. Behind this the accumulation was so great as to prevent deep penetration of the beam. In pathologic instances, c.g., juvenile retinal and vitreous hemorrhage (Eales’ disease), Vogt described several cases in which similar collections of blood were found in the anterior vitreous behind the lens but separated from it. It may be that Cloquet’s canal provides a conduit by means of which passage of the blood anteriorly is facilitated.

Vogt reported an instance following perforating injury in which retinal hemorrhages were seen around the papilla. In the vitreous most of the blood was concentrated into linear strands in the anterior portion. These strands moved very slightly. After resorption of the blood elements the coarse strands became finer and seemed to converge to the place of perforation and to the opposite side of the base of the vitreous. The remainder of the vitreous was dusted with glistening erythrocytes. After a year, the strands were still present.


1450


BIOMICROSCOPY OF THE EYE


Evidently such strand formation is a characteristic sign in perforating injuries and hence is of diagnostic importance even years after the injury.


Fig. 522. Pathologic vitreous changes following a nonperforating injury. A heavy cellular infiltration is seen throughout. Striate deposits on the posterior lens capsule. Behind the lens there are numerous crossing filaments. Deeper to this area there is a zone of pseudomembranes dusted with opacities. Still deeper there appears to be a traction band.

Pigment

Uveal pigment depositions are seen commonly following traumatism or surgical interference. This is especially true in herniation (see below) . The color of these deposits is reddish-brown. As already indicated (page 823) one must exercise caution in basing a differential diagnosis of vitreous conditions on their color alone. Pigment sometimes ma}'" agglomerate into larger collections or, being precipitated on preexisting vitreous opacities, may cause them to assume a brownish appearance. Factors influencing the judgment of color are intensity of illumination, magnification employed, screening or masking effect by the intervening tissues (e.g., senile yellowing of the deeper parts of the lens, etc.). Masses of unlaked erythrocytes will appear bright red at first. However, thin blood films similar to a microscope slide smear appear brownish to a light yellow. And even cells that appear lemon-yellow become whitish in arc illumination. Eventually, laking of the blood pigment causes loss of


BlOMICROSCOPy OP VITREOUS OPACITIES


i4n


the yellow color, even using llic ordinary nitra beam so that differentiation of red ceil derivatives from inflammatory cells is not always possible.

In the main it may be said that fresh red blood cells in aggregate will appear reddish. When disseminated or laked they will appear lemon-yellow in coloration and eventually white. Uveal pigment, on the other hand, appears reddish-brown and tends to persist so.

Wliifc Cell Elenicii/s

In exudative phenomena white cells may be seen early in the plasmoid vitreous. They lie suspended upon the vitreous framework and differ in no way from those in inflammatory conditions. Deposits in the form of white dots or striae resembling moss may also be seen on the posterior lens capsule (Figs. 521 and 522).

Leniicular Dcbrh

Following perforating injury or surgical procedures in which the lens capsule is ruptured and the lens material is macerated, fragments of cortical lenticular substance and even capsular remnants may be incorporated within or lie upon the vitreous mass. In these cases prolapse into the anterior chamber is common.

They appear as ill-defined intensely white granular fragments or portions of longer lens fibers incorporated within the surrounding disrupted vitreous.

DISRUPTIONS OF THE VITREOUS FRAMEWORK

In addition to the above-mentioned changes, trauma may affect the structure of the vitreous by causing the formation of local alterations within the framework itself, e.g., in perforating injuries It may be possible to discern a track indicating the course of a penetrating foreign body by the localized vitreous disturbance induced or by the outlining resulting from the deposition of cells or of foreign body detritus. In this respect Koby cites the work of Ogawa (i9o 6)'’'’’ who showed in experimental animals that after introduction of a cataract knife into the vitreous, the fibrillae become con


1452


BIOMICROSCOPY OF THE EYE


densed about the channel of penetration. This channel contained only a clear liquid with several migrating cells! which subsequently disappeared. From this it would appear that loosened fibrillae may retract somewhat and in such cases may favor the migration of a foreign body. Non-perforating contusion also may cause great disruption of the vitreous framework. “Liquefaction” with the formation of large dark lacunal and freely motile fibrils and cloudlike membrane may occur. Bands apparently under traction may also appear. (Fig. 522). Ffowever such bands are more common following perforating injuries or operations (needlings) or after extrusion of vitreous from the eye (cataract operations).

Herniation of Vitreom. In this discussion it is not necessary to dwell upon these instances of severe perforating injuries attended by gross extrusions of vitreous from the eye. Our concern is primarily with the intraocular herniations since their frequency and evaluation have been recognized only since the advent of the biomicroscope. The importance of zonular rupture even in minimal injuries was stressed by Frenkel in his conception of the so-called “anterior chamber syndrome” (page 913). In these cases even where subluxation may not be frankly apparent herniation of the vitreous anteriorly may occur. In the more evident lenticular displacements, prolapse of the vitreous into the anterior chamber is very common. In injuries in which iridodialysis results, herniation through the artificial pupillary orifice may be noted as a consequence of zonular rupture.

It is a daily experience with surgeons that herniation of the vitreous is found biomicroscopically after intracapsular cataract extraction procedures and especially following discissions or extractions of secondary cataracts (Fig. 523 A, B). In the latter it is extremely rare not to find some evidence of prolapse.

Ordinarily, on displacement of the lens the vitreous tends to herniate anteriorly in such manner that the anterior surface of the bulge is more or less regular. The biomicroscope will reveal only a minimal indication of the interface between the vitreous and aqueous humors because it reflects so little light. However, by imparting a slow oscillatory movement to the focal beam the tenuous surface of


Fig. 523. A. Herniation of the vitreous into the anterior chamber following discission of a wiicate secondary membrane. Surface of the bulging vitreous is .smooth and well demarcated. Near the pupillary border the faint remains of the secondary membrane are seen. b. Herniation 0 fluid vitreous into the anterior chamber following an intracapsular cataract extraction, mooth surface of prolapsed vitreous is outlined by cells.

1453


1454


BIOMICROSCOPY OF THE EYE


the vitreous can be alwa)"S recognized. Frequently in such cases it will appear as if a hemispherical bulging of vitreous hangs over the pupillary border. Because of the bulging vitreous, the border itself


Fig. 524. Herniation of fluid vitreous into the anterior chamber following trauma. Lens is displaced upwards and backwards. Note tear of iiis border below.


may be displaced somewhat anteriorly from the lens so that a noticeable separation exists at this point between the iris margin and the lens.

It often happens that following cataract extraction, adherence of vitreous to the iris and to the posterior corneal surface may by organization induce peripheral anterior synechiae and consequent secondary glaucoma.

The bulging vitreous may vary in size from a slight bead or be so extensive as to reach the posterior corneal surface. In some cases (fluid vitreous) the prolapse may be irregular and ill-defined so that no regular surface presents (Fig. 524).

The appearance of the vitreous within the herniating portion will var)’' from case to case and is composed of irregularly coarsing trabeculae and fibrillae, frequentljc containing pigment. In other in


BIOMICROSCOPY OF VITREOUS OPACITIES


1455


stances streaks of blood cells may be seen especially in the dependent portions. Depending on the consistency, dark or less reflective spaces may be seen within the mass. It has been noted by several writers that the contained blood within the vitreous has little tendency to resorb. Very commonly the lightly reflecting surface of the prolapsed vitreous is defined and made more visible by the deposition of pigment granules on the surface and this frequently makes its presence more easily recognizable. According to Koby, change in the size of the prolapse may occur especially when it is small. He has noted that diminution of size over a period of several months occurs with the smaller hernias. He suggests that the massaging action of the iris on the prolapsed mass is capable of leading to partial reduction in size.

It is interesting to speculate at this point on the nature of the anterior limiting layer of the vitreous. Vogt in his discussion considers that normally the anterior and most highly reflecting band (the plicated membrane) seen behind the rctrolental space might be considered as the anterior limiting layer of the vitreous. Since the rctrolental space in front of this contains the hyaloid vitreous it would follow in this sense that this part is extraneous to the vitreous proper. If this is the case, docs the hyaloid vitreous escape after every total lenticular extraction? It seems to me that the most anterior or plicated membrane docs not represent the anterior border layer of the vitreous; that it is the hyaloid membrane itself which probably IS in contact with the posterior lens surface, and that only a potential postlenticular capillary space exists. In this case, because of the high degree of reflection of the posterior lens capsule, the anterior limiting layer of the vitreous is not apparent biomicroscopically. Perhaps the only time it is visible is after intracapsular operations and herniations." As to the tenuous surface of demarcation between the aqueous and herniating vitreous, Duke-Elder states: "The apparentl} distinct membrane is probably a mechanical effect of the tension and

Following intracapsular cataract extraction, where herniation of the vitreous is commonly seen, rupture of the "hyaloid” and spilling of vitreous substance into the anterior chamber may occur spontaneously months postoperatively. This phenomenon may be attended by s ig t Cl lary injection. Improvement in visual acuity has been noted following such an episode.


1456


BIOMICROSCOPY OF THE EYE


stress created by the hernia on the micellar structure of the gel, causing a rearrangement, a reorientation and a condensation of its fibrillar elements.”

Would this process be instantaneous? Following a traumatic herniation into the anterior chamber, I have seen within two hours a typically outlined vitreous bulge with a surface such as that described above. Similarly, on the day following a discission of a secondary membrane (where the hyaloid membrane was certainly incised) a smooth bulging and sharply delimited herniation of interior into the anterior chamber was observed. And how shall we explain the cases of vitreous prolapse following discission, trauma or intracapsular cataract extraction in which an irregular extrusion of vitreous occurs and in which no smooth or rounded delimiting surface is seen? Such differences in the appearance of herniated vitreous probably depend on its physical aspects; thus representing in one case a more or less turgid gel-like consistency and in the other a higher degree of fluidity. Practically, this has been well known for a long time to surgeons when witnessing vitreous escape during operative procedures. It will take considerably more experimental investigation before one can give any definite opinion concerning tills problem. Perhaps if some specific method of intravital or histologic selective staining could be devised, light might be shed on these questions.

Larger hernias seem to persist indefinitely. The prolapsed vitreous trembles somewhat upon movement of the globe. In several of Koby’s cases he noticed a sagittal oscillation accompanying pupillary movements. St. Martin describes also a pulsation synchronous with the arterial pulse.

Several authors, St. Martin, Poyales and Moreno (1934)/'’^ their studies of prolapse after total extraction of the lens, found a very high incidence of anterior prolapse of the vitreous. According to these writers it will be seen at times that the “hyaloid” is torn as indicated b}^ irregular borders. In other cases a large hemispherical bulging of the vitreous will be observed; its surface may or may not be marked by deposits. Herniation or prolapse of the vitreous


BIOMICROSCOPY OP VITREOUS OPACITIES


1457


into the anterior chamber during or following extraction of the lens may be a factor in the causation of delayed restoration of the anterior chamber, distortion of the pupil, anterior peripheral synechiae and


A D

Fig. 525. A. Herni.Ttion of formed vitreous into the anterior cliamber following an intracapsular cataract e.xtraction. Observe the sharp outline of the vitreous surface to the left. Deeper veils of disturbed and relucent vitreous arc seen. (After St. Martin.) ii. Diagram of a.


consequent secondary glaucoma. This may result from the organization of vitreous bands (Figs. 525 A, B; 526 A, B).

When loss of vitreous occurs during an intracapsular extraction bands of vitreous may be found drawn up to the corneal wounds. Similar bands are often seen following discissions of secondary membranes. After the extrusion of any considerable amount of vitreous from the eyeball, especially if it is "formed” or nonfluid, opacification of the retained vitreous will occur. This opacification results from cellular infiltration and condensation of the framework.


1458


BIOMICROSCOPY OF THE EYE


Prolapse or loss of vitreous following extracapsular operations mayresult in a mixture of soft lens matter and vitreous. In such cases the intermingling of vitreous material will hinder the absorption of lens cortical substance and may contribute to untoward sequelae.


A B


Fig. 526. A. Herniation of fluid vitreous into the anterior chamber following intracapsular cataract extraction. Note the irregular masses of vitreous protruding into the anterior chamber. No demarking surfaces are seen. B. Diagram of A. (After St. Martin.)

After extracapsular cataract extraction and in the absence of a dense secondary membrane, the posterior capsule can be differentiated easily from the vitreous behind it. With the narrow beam the posterior capsule alwaj'^s appears as a definitive line.

As mentioned above, prolapse of the vitreous always occurs following discission of a secondary cataract. The surface of such a prolapse may or may not be outlined sharply. Sometimes the surface is composed of irregular fluffs and strands and in other instances it is more sharply delineated by the presence of pigment or small whitish


BIOMICROSCOPY OF VITREOUS OPACITIES


1459


precipitates. Dcjcan, (i92 5),‘""‘ St. Martin (1930-1935)5 Koby (1939) "’ believe that the delineation of the prolapsed surface (which some have held is due to a kind of condensation) is due rather to a pathologic change dependent on precipitation.


Fig. 527. Kcr.itovitrccuis syncclii.!. Vitreous aiul sonic c.ipsular remains drawn up into the corneal wound following discission of a secondary cataract. Observe the disturbed vitreous (pseudomembranes and cellular deposits).

Not uncommonly after discissions, a tract of vitreous may be drawn up to the corneal wound to which it may become adherent forming a kerato-vltreous synechia. That this occurs very frequently after discission has been brought out by biomicroscopic examination. At the point of corneal adhesion, disturbances of Descemet’s membrane may occur (opacifications, folds, and tears) . It has also been shown by Methy (1924) that such kerato-vitreous synechia may be established following electromagnetic extraction of a foreign body. Apparently in discission the vitreous is drawn up by the knifeblade as it is withdrawn. Adhesions of this nature are permanent (Fig. 527).


FOREIGN BODIES IN THE VITREOUS


All manner a result of a


of foreign bodies may gain ingress to the vitreous as perforating injury. The tract may be evidenced by


1460


BIOMICROSCOPY OF THE EYE


corneal or scleral scars. (See VoL I, page 547 and Vol. II, page 1235.) However, in the case of the scleral perforation it frequently happens that after the absorption of initial conjunctival hemorrhage no evidence of its passage may be found. In the instance of a sterile foreign body its presence may be clearly seen ophthalmoscopically because of the lack of inflammatory reaction provided extensive hemorrhage is not also present. Those lodged in the anterior parts of the vitreous may be seen with the biomicroscope. To facilitate this the pupil should be dilated maximally.

Foreign bodies distant from the ciliary body or retina are less liable to cause foreign-body reactions than those situated close to those two tissues. Depending on the nature of the substance, the foreign body may be well tolerated in the vitreous for long periods of time. This is especially true of many metallic substances excepting the ferrous and cuprous compounds or their alloys, which rapidly dissolve leading to siderotic and chalcotic changes. Since a larger percentage of the intravitreous foreign bodies are of a ferrous nature the importance of early removal is apparent. The "noble” metals are best tolerated in the order of platinum, gold and silver; the less oxidizable substances such as chromium and aluminum or the silicates are also well tolerated. Since modern alloys vary considerably in their composition no general rules concerning reactions in the vitreous can be formulated. For example, in a personal observation, a piece of brass has been seen in the vitreous relatively unchanged and with no ocular damage or effect upon vision over a span of years. With the ophthalmoscope it appears as a freely mobile golden glittering speck.

As a consequence of war wounds, especially due to mines, the incidence of intravitreous nonmagnetic fragments has been increased. Fragments of greenish plastic from German mines, porcelain, clay or glass from both German and Japanese mines, wooden splinters and gunpowder particles have all been seen at one time or another.

It has been reported that globes containing glass fragments or lead

Those lying deeper may be seen biomicroscopically by means of the contact lens (mirror or prism) provided they are not located too far peripherally; in this case they may be seen ophthalmoscopically.


BIOMICROSCOPY OP VITREOUS OPACITIES


1461


granules, after remaining quiescent for a long period of years, may suddenly flare up into activity. In siderosis, Vogt has described whitish opacities of a size varying up to 0.05 mm. Some of the larger ones were pigmented. The remainder of the framework also contained fine brown to reddish opacities.

Of all the common metals, copper is probably the most toxic. In association with chalcosis lentis the biomicroscopic examination of the vitreous may disclose similar (greenish) discoloration of the disrupted framework. Where lead particles have penetrated the vitreous the shiny nature of the globules may be seen for very long periods. Likewise aluminum particles exhibit a shiny appearance.

As a consequence of penetrating wounds, it is obvious that air may be entrapped in the form of single or clusters of bubbles which rapidly absorb. With the ophthalmoscope the appearance of the reflex from them will vary depending upon the direction of light.

It should be recalled that the disruptive influence of foreign bodies causes formation of tracts often outlined by blood cells.

I N •[•R A - O C U L A R P A R A S ITIZ S

Parasites invade the eye rarely. Nonetheless consideration must be given the possibility whenever an unusual vitreous cyst or mass is found. Of all parasites, worms and fly larvae are reported as being most frequently found in the eye. The former or nematelminthes (round worm) is represented by filaria (thread worms), and platyhelminthes (cysticcrcus and echinococcus).

Filarial infestation of the eyes is exceedingly rare insofar as filaria loa, Bancrofti, and medinensis are concerned, but the onchocerca volvulus (microfilaria) invades the eye in most cases and constitutes an important cause of blindness in Africa and the American continents where the organism is endemic.

Infestation by adult forms of filaria have been recorded at times as involving the anterior chamber, lens, vitreous and subretinal space. The motile filaria may be discerned actually lashing about in the aqueous, causing subjective symptoms by the entoptic phenomenon resulting as it whips aci'oss the pupil. An inflammatory


1462


BIOMICROSCOPY OF THE EYE


reaction, iridocyclitis with cloudy aqueous and vitreous opacities are associated with most cases. Worms first seen in the anterior chamber may subsequently migrate to the vitreous and become lost or die and become calcified. In other instances marked inflammation incites secondary glaucoma and loss of the eye following such migration.

Appearance of filaria in the vitreous must be differentiated from filamentary opacities or hyaloid vascular remnants. Reported appearances are vague. The authentic cases include an instance in which a filaria travelled from the anterior chamber to the vitreous, another in which the organism migrated from a subretinal site to the vitreous chamber and thence to the anterior chamber whence it was extracted via a keratome incision. Kuhnt (1892) reported a case in a 3 1 -yearold man. A pinhead white swelling, paramacular, increased in size in two months and a worm protruded into the vitreous five months later, movements were discerned in the swelling and following a scleral incision the parasite was removed. It was proved to be a nematode. Barrada (1934) reported a case in a 15-year-old Egyptian.®'"^ A red circular hole was seen near the macular encompassed by a raised darkish zone radiating from which were innumerable reflexes of folds of the internal limiting membrane. The vitreous was clear. The patient saw a long black string waving about. Later the filaria disappeared leaving the central hole and opaque film over the surrounding area. Leber (1914) attributed retinal hemorrhages and exudative retinitis to blockage of vessels by microfilaria of F. bancrofti.

In onchocerciasis the invasion of the vitreous chamber by microfilaria has been proved to occur. Inflammatory sequelae are the rule. All parts of the eye ma) be affected concomitantly or consecutively. Entoptic phenomena due to the lashing motile microfilaria may be noticed subjectively.

Ridley (1945)'’“ in an account of an investigation in the Gold Coast among Negroes living in an endemic area found extensive ocular microfilarial invasion throughout the eye. Although the vitreous was not involved alone in his series of cases he notes that in this disease "In the absence of iridocyclitis clarity of the vitreous


luoMicKosc'.opv cii- vri RUcu’s ()i’Acrrii-:s


H 63


seems 10 be the rule even wiili inarbcil clioroidoretinal lesions though a lew opacities such as one of very general occurrence were seen.” Silva (59:15) ' Joicrofilaria iti the vitreous using a ]')lanc niiri'or and Gullsii-and ophthalmoscope. 'Korres Ivstiada (i9.}2) I'ccords seeing worms swimnting freely in the vitreous using a slit lamp witli a Koepjw mirror and also hy means of an electric ophthalmoscope with a d- 10 or d .}o lens. *rhiv writer asserts that microfilaria ai'c commoner in the vitietius than in the aqueous. Cases of viti'cous degeneiMtioit of the aster<nd hyaliiis type have been seen, hut while onchoceixiasis of the eye is a highly jsrevalent endeittic cause of blindness it is 5 iot felt that the vitie<nis is the mtjst likely site of infestation with the mici'olilaria. It is to he noteil that in some cases in which hlaria were ilemonstrahle in the anterior chamber, the anterior segment was normal. This has caused some to believe that the entrance of the worms is via the posterior ciliary vessels.

Mowcvei-, today there is little doubt hut that the mici'ofllaria gain entrance into the eye hy iitvading and penetrating the cornea. Reaction in the cornea and within the anterior segment of the eye pi'ohahly depetids on the number of microfilaria j^i’esent and upon the degree of toxicity excited.

The flat worms (Platyhelminihes) are I’epresented hy invasive foi'ms of Taenia solium, the cysticercus cellulosae of which arc carI'icd to the eye hemaiogenously. The commonest site is subi'ecinal. The life of the oi'ganlsm is two to four years and although initially tninutc, later accretion in size may lead to destruction of the eye. Dukc-Llder describes the appearance as a cystic swelling, globular and ti'ansluccnt with its wall studded with fine calcareous granules. Lcech-Iikc or heaving movements have been noted. The occurrence in the viti-cous is common. Extensive I’ctinal separation may result, possibly associated with migration of the pai'asitc within the fundus. Although oi'iginating elsewhei'e, the oi'ganlsm may migrate to the vitreous chamber, its passage thi'ough the retina being attended by a violent reaction with marked formation of vitreous opacities. Airest during the passage may occur and the head become fixed suprachoroidally. If initially in the retina, it escapes readily into the


1464


BIOMICROSCOPY OF THE EYE


vitreous and is easily seen. While in the vitreous it may be well tolerated but an eventual uveitis ensues.

Diagnostic confusion of a parasitic cyst with embryonal rests in

ABC



Fig. 528. Free cysticercus in vitreous body. Two of the four suckers may be seen in the lower right picture. (Courtesy of Dr. J. Lech, Jr.)


the vitreous, especially cystic dilation of the hyaloid artery, or with a site of retinitis proliferans (Coats) or with a neoplasm (such as glioma), should be kept in mind. If a cysticercus is suspected, effort should be made to visualize the head (ophthalmoscopically and/or biomicroscopically) or the neck of the organism. The undulatory or peristaltic movements are characteristic but often absent (Fig. 528) .

While in the vitreous the preretinal site is commonest; the cysticercus may be more central or it may come closer to the lens. Exceptionally, forward migration to the anterior chamber has been noted. Diagnosis is facilitated by noting the globular translucent swelling formed by the head, intracystic heaving movements and undulations. Stimulation of these movements by temporal galvanization or faradization is suggested. A migratory subretinal cyst is always suggestive of cysticercus. Hooked scalices may be visible. The


i5K>Mi('.iu\s( ('»PY (11- vrrKi:(')i’.s (.')i>Ac:rni;s


biomicroscopic stuily «)f a suspcctcil cy.sticcrciis is important in any consideration ol its removal iransclcrally to prevent furiber destruction of liie eye. Oismetiatos and Atiargyros (192^) recommend subconjunctival injection t>f a hypertonic saline s{)lution ti to to per cent to clear the vitreous aiul aho to provoke an eosinophilia.

Upon invadiny the eye raetiia echinococcus larvae yivc rise to a hydatid cyst. Intra-ocular f>ccurrence is rare, rarer than cysiiccrcus. Authenticated instances are imcommon. Ciescheidt (1S33)'"' described a reiroleniicular yellowish opacity. Ctrifhths (1897) reported a glisieniny white opaipie nonvascular opacity in contact with a clear lens. W’erner (1903) Pnjiul a yrayish white mottled opacity behind the lens. A hytlatltl cyst was found on section. Scholl/, reported an ituerestinj; apjsearance in the vitreous of a mass of some 20 small clustered ylohular vesicles which eventually beccune obscured by proyressive vitreous opacification.

Burrowiny within the eye by the larvae of various flies (ophthalmomyiasis interna) has been noted. *rhe inciilence amony youny children is yreater than amony adults, probably because of the softness of the scleral tunic. Miyr.uion to the vitreous evokes considerable reaction, but while in the vitreous less disturbance ensues. DcBoc (1933) reported subsetjuent larval inactivity, and Anderson (^93-}) noted shrivelliny of the larva without ocular damaye. If the larva is seen, diaynosis is eviiicni but if not. it is niyh impossible. Early and frequent biomicroscopic examination of suspected instances Is recommended.


Bibliography for volume 2

',44. Ac.mmon, S. a.. ANii CiAHiNiu. S. l’icc<ict(His CAiaracts and scicrodcnn.i (Rotljjnuturs 'â– -ynclrninc: Werner’s syndrome); Report of c.nc. An/r. O/iA/A,. ;i : 4«_ji-496. J939.

^4j. Ai.l.t N‘. j. 1 1 .. ANt» KaJ'.! k. C'.. (7. C^tt.iraft ol dystrophia inyoionica. ArrA. OhAfh.^ z.i : Sop-SK4. 1940.

',4t). AntNo. A. N. I*\f<i!iatiiin c»t the lens capsule. Arch. Oph/b..

1-4. I9; 7. 347 . Axni KsoK. J. R. I lole in '"po>.terii>r hyaloid-memhrane" oi vicreotis - report o 5 can'. Ihif. f. O/iA/A.. i~ : 460. 1933.

34S. ANDOt.sKV. N. Chit.irae;a siermatoyenes. l-.in Heitray /ur .Aeliologie dor Liiuentriilniny. .M/o;.j/<A/. /. ,\//yc//A,. 3a;S;4-S3i.

OM 349. Aschik. K. \V'. RingjUrmiye iKuiuny in die hiniere Rammer nach

perforierender Lederhatiis erlet/iinj;. RA'?;. .Mo;;.;/'A/. /. A.,

fit ; 377. 19^0.

350. Avi/ONts. P. AnfilclUins: ciner Ktnuiisionskatarala. Z/scAr, /.

Auy^enh., 30 : x i\. 19 ^ 3 .

351. BaI!, Wi kni r, uher Auyenveranilerunyen hei lympltaiischcr

I.cuk.imie. 7 Ju'hr. j. Au^iuh.. 47 ; Z 31 . jpaa,

352. Bach. L. Patholoyiveh-anaiomisclte Stmlien iiher vcrschicdene

Misshildunyen des .'Xuyes. An'h j. Ophth., 43 ; i, 1898.

3 33" Bakkan, O. Divciisvion of Butler, T. H.: Capsular glaucoma. Tr.

Opb/b. Snc. V. Khixiilorii. 38 : pi. 38.S-3.S9, 193.S.

334 - Bakrada, M. A. I'ilaria in mactila. HiilL Opbfb. Sor. Ii}iypfs 27 : ^ 3 "^ 7 * 034 333 - Barkos, j. M. di . Clinical aspects of the ocular involvement in Lepers, Servico de Profilaxia ila Lepra da Hsiado de Sao Paulo - Brasil, 1939.

33C Battiin', P. E,. and Gtnn. M. P. Myotonia Atrophica, Bruin 32 : 187-203, 1909.

337 ‘ Baumgart, B. Considera/.ioni suiPexfoliaiio superficialis capsulac di Vogt. Boll, il’ocni., 12 : 3A0-397, 1933.

33 ^- Baurmann, M. Uehcr die Beziehungen tier ultramikrokopischen Glaskocrpcr.ssiruktur zu den .Spalilampenbefunden. Arch. /. Ophih., 117 ; 304, 1 92 A.

339 * Buckrr, O, Paihologie und Therapie des Linscn.sy.stcms. Handbuch dcr gesamten Augenheilkunde. Leipzig, Engclmann, i : 13A-520, 1874-1880.


}6o. Becker, O. Pathologic und Therapie des Linsensystems. In Graefe, A. and Saemisch, T.: Handbuch der gesamten Augenheilkunde, Leipzig, W, Engelmann, 5 (Chap. 7): 157-520, 1877.

3^1. Bedell, A. J. Studies of vitreous. New York State J. Med., 24 : 712-720, 1924.

3^2. Bedell, A. J. A study of the vitreous with the slit-lamp. Tr.

Ophth. Soc. U. Kingdom, 45 : 6^413-^57, 1925.

3(33. Beetham, 'W. P. Atopic cataracts. Arch. Ophth., 24 : 21-57, 1940.

364. Bellows, John G. Cataract and Anomalies of the Lens. St. Louis,

C. V. Mosby Co., 1944, p. <324.

365. Berger, E. Beitrage zur Anatomic der zonula Zinnii. Arch. f.

Ophth., 28 : pt. 2, 28-(32, 1882.

3(3(3. Berliner, M. L. Cysts of the cornea. Arch. Ophth., 7 : 224, 1932. 367. Berliner, M. L. Cataract following the inhalation of paradichlorbenzene vapor. Arch. Ophth., 22 : 1023-1033, 1939.

3(38. Bleisch. Scheinkatarakt bei Anwesenheit einer Fremdkorpers (Kupfersplitters) im Augeninnern. Berlin, klin. W chnschr., 5^ : 117, 1919.

369. Bouchard and Charrin. La cataracte produite par la naphta line. Compt. rend. Soc. de bioL, 8 : (314-615, 1886.

370. Briere. Note sur un cas de decollement du corps vitre suivi de

guerison. Ann. d'ocuL, 74: 138-145, 1875.

371. Bruckner, A. Ueber Persistenz von Resten der Tunica vasculosa

lends. Arch. f. Angenh., 56 : Supp. pp. 5-49, 1907.

372. Brunsting, L. a. Atopic dermatitis (disseminated neuroderma titis) of young adults; Analysis of precipitating factors in loi cases and report of 10 cases with associated juvenile cataract. Arch. Dermat. Syph., 34 : 935-937, 1936.

373. Bucklers, M. Spektrographische Untersuchungen iiber die Ab sorption des Lichtes durch die menschliche Linse. Ber dtsch. Ophth., 48 : 234-236 and 251-254, 1930.

374. Bucklers, M. Erbleiden des Auges. Leipzig, G. Thieme.

375. Buhl and Rothmund. Uber Cysten der Regenbogenhaut. Klin.

Monatsbl. f. Angenh., 10 : 189-223, 1872.

376. Busacca, a. Formazioni fibrillari tonofibrille mell’ epitilio del

cristallino. Monitore zool. itaJ., ii : 271, 1927.

377. Busacca, A. Ueber die Fettinfiltration des Ziliarkorperepithels.

Klin. Monatsbl. f. Angenh., 78 : 529-533, 1927.

378. Busacca, A. Ueber ein neues Spaltlampenbild in der Aequatori alregion der Linse, Anwesenweit einer Linsenkapselfalte entland dem Aequatorrande. Klin. Monatsbl. f. Angenh., 79 : 518-524, 1927.



37p, Busacca, a. Struktur und Bedeutung der Hautclien-niederschlage in der vorderen und hinteren Augenkammer. Arch, f. Opbth., 119 : 135-^6, 1827.

380. Busacca, A. Anatomischc und klinischc Beobachtungen uber die

Zonulalamelle und ihrc Ablosung von der Linse. Kliu. Moncifsbl. f. Aiigcnh., 83 : 737 - 757 . i 9 ^ 9 *

381. Butler, T. H. Lenticonus posticum and allied anomalies at the

posterior pole. Tr. Ophtb. Soc. JJ. Kingdom, 57 : pt. 2, 412-430, 1938.

382. Byers. The ocular manifestations of systemic gonorrhoea. Studies

from the Victoria Hosp., Montreal, 2 : No. 2, 1908.

383. Cattaneo, D. Morbo di Ra3maud c cataratta. Arab, di offal., 38 :

684-702, 1931.

384. Clapp, C. A. Significance of syphilis as an etiologic factor in acute

iritis. Am. J. Opbfb., 4 : 194-196, 1921.

385. Clarke, C. C. Ectopia Icntis, a pathologic and clinical study.

Arcb. Opbib., 21 : 124-153, 1939.

386. Collins, E. T. Developmental deformities of the crystalline lens.

Opbfbalmoscopc, 6 : 377-5^3? 663-676, 1908.

387. CoMBERG, W. Zur Frage der vorderen Glaskorperbegrenzung, 43

Verslg. dtsch. Ophth. Ges. Jena, 1922, p. 259.

388. Cowan, A. Concerning membrane between the vitreous and the

anterior chamber, seen after removal of the crystalline lens and its capsule. Aw. }. Opbfb., 15 : 123, 1932.

389. Cowan, A., and Fry, W. E. Secondary cataract with particular

reference to transparent globular bodies. Arcb. Opbfb., 18 : 12-22,

1937 390- Cowan, A., and McDonald, R. After-cataract. Arcb. Opbfb., 22 : 1074-1078, 1939.

391* Daniel, R. K. Allergy and cataracts. Tr. Seef. Opbfb., A.M.A., ^ 93 C p. 30-59; }-A.M.A., 103:481-483, 1933.

192. Davidson, M, The minor ocular sequelae of eye contusions. Am. J. Opbfb., 19 : 737, 1936.

393 - Davidson, M. The minor ocular sequelae of eye contusions. Am. f.

Opbfb., 19 : 764, 1936.

394 - Davidson, M. Lens lesions in contusions; a medico-legal study.

Am. J. Opbfb., 23 : 232-271, 1940.

39 3 - Davidson, M. Evolution of lens lesions in eye perforations and ruptures; medico-legal study. Am. J. Opbfb., 23 : 1338-1375. 1940.

39 ^- Dejean. Notes sur la forme et la structure du corps vitre a la lampe a fente. Arcb. d’opbf., 46 ; 477-481, 1923.

397 * Dejean, C. Sur I’origine des fibres de la zonule. Compf. rend. Soc. de biol., 92 ; 1031-1052, 1925.


1470


BIOMICROSCOPY OF THE EYE


398. Demicheri, L. Faux lenticone. Amu d’ocuL, 113 : 93-10^, 1895.

399. Dollfus, M. Degenerescence irienne d’un type particulier. Bull.

Soc. d'opht. Paris, 37 : 170-172, 1927.

400. Duke -Elder, W. S. Recent Advances in Ophthalmology. Ed. 3,

Philadelphia, Blakiston, 1934, p. 434*

401. Duke-Elder, W. S. A Text-Book of Ophthalmology. St. Louis,

C. V. Mosby Co., Vol. 2, p. 32^4, 1938.

402. Duke-Elder, 'W. S. Diseases of the uveal tract. In A Text-Book of

Ophthalmology, Vol. 3, p. 2097, 1941.

403. Duke-Elder, W. S. A Text-Book of Ophthalmology, Vol. 3, p.

2231, 1941.

404. Duke-Elder, W. S. Exudative uveitis in chapter 35, Diseases of

the uveal tract. In A Text-Book of Ophthalmology, Vol. 3, p. 2251, 1941.

405. Duke-Elder, W. S. A Text-Book of Ophthalmology, Vol. 3, p.

2253, 1941.

406. Duke-Elder, W. S. A Text-Book of Ophthalmology, Vol. 3, p.

2290, 1941.

407. Duke-Elder, W. S. Diseases of the uveal tract. In A Text-Book

of Ophthalmology, Vol. 3, p. 2291, 1941.

408. Duke-Elder, W. S. A Text-Book of Ophthalmology. St. Louis,

C. V. Mosby Co., 1941, Vol. 3, p. 297C

409. Duke-Elder, W. S. Ibid., Vol. 3, p. 3205.

410. Duke-Elder, W. S. Ibid., Vol. 3, p. 3245.

41 1. Duke-Elder, W. S. Ibid., Vol. 3, p. 3247.

412. Duke-Elder, W. S. Ibid., Vol. 3, p. 3248.

413. Duke-Elder, W. S. Ibid., Vol. 3, p. 32(35.

414. Duke-Elder, 'W. S. Ibid., Vol. 3, p. 327(3.

415. Ebner, V. von. Handbuch der Gewebelehre. Vol. 3, p. 8^2, 1902. 41(3. Ellett, E. C. (a) Leiomyoma and (b) hematoma of the iris.

Arch. Ophth., 21 : 497, 1939.

417. Elschnig, a. Klinisch-anatomischer Beitrag zur Kenntnis des

Nachstares. Klin. Monatsbl. f. Angenh., 49 : pt. i, 444-451, 1911.

418. Elschnig, A. Abldsung der Zonulalamelle bei Glasblasern. Klin.

Monatsbl. f. Angenh., 6^9 : 732-734, 1922.

419. Elschnig, A. Uber die Zonulalamelle. Arch f. A^igenh., loo-ioi :

jGo, 1929.

420. Erb, W. H. Die Thomsen’sche Krankheit (Myotonio congenita).

Leipzig, 188C

421. Erggelet, H. Klinische Befunde bei fokaler Beleuchtung mit der

Gullstrandschen Nernst-Spaltlampe. Klin. Monatsbl. f. Angenh., 53:449,1914.

422. Ertl, F. Fremdkorper (Kupfersplitter) im Glaskorper-Linsenbilder

in Regenbogenfarben. Xentralbl. f. prakt. Angenh., 31 : 322-32C 1907.


BIBLIOGRAPHY


1471


424. Estrada, A. T. Ophthalmoscopic observation of microfilarias in

the vitreous of patients infected with onchocerciasis. Am. }. OpJjfh., 25 : 1445-1448, 1937.

425. Evans, P. J. Atrophy of the optic nerve and naevus flammeus as sociated with hemangioma of the choroid - report of a case. Arch. Ophth., 18 : 193, 1937.

42^. Feigenbaum, a. Origin of Lenticonus anterior. Folia Ophth. Orient., 1 : 103-108, 1932.

427. Fine, M., and Barkan, FI. Essential progressive iris atrophy. Am.

J. Ophth., 20 : 277, 1937.

428. Fisher. Coralloform cataract, Tr. Ophth. Soc. U. Kingdom, 28 :

90, 1905.

429. Fleischer, B. Ueber myotonische Dystrophic mit Katarakt. Arch.

f. Ophth., ^6 : 91-133, 1918.

430. Foster, J. Subepithelial disseminated traumatic cataract of Vogt.

Tr. Ophth. Soc. U. Kingdom, 58 : pt. i, 436-437, 1938.

431. Frenkel, FI. Reflexions sur quelques termes employes en ophtal mologie. Arch, d’opht., 48 : 205-215, 1931.

432. Frost, A. D. Leiomyoma of the iris: Report of a case. Tr. Am.

Ophth. Soc., 34 : 86, 1936.

433. Fuchs. Lehrbuch der Augenheilkunde. Wien, Deuticke, 1910.

434. Fuchs, A. Contribution to the anatomy of congenital ectropium

uveae (flocculi iridis). Am. J. Ophth., 14 : 865-868, 1931.

435. Fuchs, E. Melanoma of iris. Arch. Ophth., 12 : 26, 1883.

436. Fuchs, E. Anatomische Miscellen. Glaucoma inflammatorium, Iritis

syphilitica. Arch. f. Ophth., 30: 123, 1884.

437. Fuchs, E. Naevus pigmentosus und Naevus vasculosus der Iris.

Arch. f. Ophth., 86 : 155, 1913.

439. Fuchs, E. Textbook of Ophthalmology. Ed. 5. Philadelphia, Lip pincott, 1917.

440. Fuchs, E. Zur patholog. Anatomic v. Glaskoerperblutungen.

Arch. f. Ophth., 99 : 202, 1919.

441. Fuchs, E. Der Ciliarkorper bei Luxation der Linse. Arch. f. Ophth.,

122 : 86-95, ^9^9*

442. Gabrielides, a. Contribution a Fetude des cataractes electriques.

Arch, d’opht., 52 : 394, 1935.

443. Gala, A. Iodine content of the aqueous humor of the human

eye following parenteral, oral and external administration of iodides. Opthal. Sbornik, 2 : 229, 1928.

444. Gallati, j. Die relativen Dickenwerte von Rinde und Kern der

menschlichen Linse in verschiedenen Lebensaltern. Xtschr. f. Angenh., 51 : 133-144, 1923.


1472


BIOMICROSCOPY OF THE EYE


445. Garrow, a. Exfoliation of lens capsule in glaucoma. Brit. J. Ophtb., 21 : 214-230, 1938.

446'. Gescheidt. Die Entozoen des Auges. Xfsch'r. f. Ophtb., 3 : 437, 1833.

447. Gifford, S. R. Congenital anomalies of the lens as seen with the

slit lamp. Am. J. Ophtb., 7 : 6 y8-68$, 1924.

448. Gifford, S. R., and Puntenney, I. Coralliform cataract and new

form of congenital cataract with crystals in lens. Arch. Ophtb., 17 : 884-892, 1937.

449. Gifbert, W. Uber intraokulare Tuberkulose. Miincb. vied.

Wchschr., 61 : 3o(i, 1914.

450. Gifbert, W. Die Erkrankungen des Uvealtraktus. Graefe-Saemisch

Handbuch, 2 aufl., 1922.

451. G JESSING, H. G. A. Untersuchung in maximaler Mydriasis von

4768 Augen im Alter von 3 Monaten bis zu 87^2 Jahren mit punktuell abbildendem Licht, und zwar in besonderem Hinblick auf die Vogtsche sog. Coronarkatarakt. Klin. Monatsbl. f. Angenh., 6$ : 233-2^5, 1920.

452. Goldman, H. Genesis of heat cataract. Orch. Ophtb., 9 : 314,

1933.

453. Goldmann, H. Studien iiber den Alterskernstreifen der Linse.

Arch. f. Angenh., no : 405-414, 1937.

. 454. Goldsmith, J. Dynamics of intracapsular cataract extraction. Arch. Ophth., 29 : 380-434, 1943.

455. Goldzieher, "W. Ueber den Fall eines seit 10 Jahren in der

Netzhaut verweilenden Kupfersplitters, nebst Bermerkungen iiber Impi'egnation der Netzhaut mit Kupfer (Chalkosis retinae). ZentralbJ. f. prakt. Angenh., 19 : 1-6, 1895.

456. Goulden, C. Some unusual forms of acquired cataract. Tr. Ophth.

Soc. U. Kingdom, 48 : 97-ioC 1928.

457. Gradle, H. S., and Sugar, H. S. Concerning chamber angle; ex foliation of zonular lamella and glaucoma capsulare. Am. J. Ophth., 23 : 982-997, 1940.

458. Granston, K. O. Refraktionsveranderungen bei Diabetes mellitus.

Acta Ophth., ii : 3-1^0, 1933.

459. Graves, B. The response of the lens capsules in the act of accom modation. Tr. Am. Ophth. Soc., 23 : 184-198, 1925.

460. Greenfield, J. G. Notes on a family of “myotonia atrophica”

and early cataract, with a report of an additional case of “myotonia atrophica.” Rev. Nenrol. Psycbiat., 9 : i<39-i8i, 1911.

4^1. Groenouw, a. Syphilis des Auges. Graefe-Saemisch Handbuch, II, xi(L):737, 1904.

462. Grzedzielski, j. Ueber die Linsenkapselhautchen bei Glaukom


BIBLIOGRAPHY


1473


(Glaucoma capsulare Vogt). Arch. f. Ophth., 12^:40^-423, 1931.

4^3. Gullstrand, a. Die Nernstspaltlampe in der ophthalmologischen Praxis, 4. Jverslg. schwed. Augenarztl, ver. Stockholm. Klin. Monatsbl. f. Angenh., 50 : 483, 1911,

464. Gullstrand, A. Einfuhrung in die Methoden der Dioptrik des Auges des Menschen, 1911, p. 91; Hdbch. d. physiol, optik. Ed. 3, Hamburg, i : 22(^-376^, 1909-1911.

4^5. Gunn, R. M. Peculiar coralliform cataract with crystals (?) of cholesterine in the lens. Tr. Ophth. Soc. U. Kingdom, 15 : 119, 1895.

466. Guttmann, E. Doppelte Refraction auf einem Auge in Folge von Kernsclerose. Xentralbl. /. prakt. Angenh., 22 : 193-198, 1898. 4^7. Haab, O. Augenspiegel-Studien. Arch. f. Angenh., 85 : 113, 1919. 4<j8. Halben, R. Scheinkatarakt. Arch. /. Ophth., 57 : 277-341, 1904. 4^9. Haldimann, C. Beitrag zur traumatischen Spatrosette der Linse. Ophthcihnologica, 103 : 302-307, 1942.

470. Herrenschwand, F. V. fiber das Heterochromieglaukom und

andere Formen von Uveitis mit voriibergehender Drucksteigerung. Arch. f. Angenh., 95 : 103, 1924.

471. Hess, C. Zur Pathologie and pathologischen Anatomic verschiede ner Staarformen. Arch. f. Ophth., 39 : pt, i, 183-220, 1893.

472. Hess, C. Pathologie und Therapie der Linsensystems. In Graefe, A.

and Saemisch, T.: Handbuch der gesamten Augenheilkunde. Ed. 3. Leipzig, "W. Engelmann, 1911, pt. 2, Chapter 9.

473. Hillemanns Bemerkenswerther Fall von Zundhiitchenverletzung.

Arch. f. Angenh. 32 .*202, 1896.

474. Hirschberg. Einfuhrung in die Augenheilkunde. Leipzig, G.

Theime, 1901, p. 139.

475. Hirschler, J. Zum Rothsehen der Aphakischen. Wien med.

Wchnschr., 33 : 89; 125; 149, 1883.

476^. Hoffmann. Zur Frage der intravitalen Existenz des Glaskoerperkanals beim Menschen. Klin. Monatsbl. f. Angenh., 77 : ^41, 192^. 477. Holloway, T. B. Asteroid hyalitis. Tr. Am. Ophth. Soc., ij : 15-3, 1917.

47^* Holloway, T. B., and Fry, W. E. Microchemical and histological findings in a case of asteroid hyalitis. Tr. Am. Ophth. Soc., 27 : 165, 1929.

479. Holloway, T. B., and Cowan, A. Concerning lamellar mem branes of anterior surface of lens. Am. J. Ophth., 14: 189-1^5,

480. Horlacher, j. Das Verhalten der menschlichen Linse in Bezug auf die Form von Alterstriibungen bei 1^6 Personen im Alter von 51-81 Jahren. Xtschr. f. Angenh., 40 : 33, 1918.


481. Horner, F. Zur Casuistik der Memb. pupilli perseverens (Drei

Falle). Klin. MoncitsbJ. f. Angenh., 4 : 259-2^1, 1S66.

482. Horven, E. Exfoliation of the superficial layer of the lens capsule

(Vogt) and its relation to glaucoma simplex. Brit. J. Ophth., 21 : (325-^37, 1937.

483. Igersheimer, J. Syphilis u. Auge. Berlin. J. Springer 1918, 2 ed. 1928.

484. Irvine, R. Exfoliation of the lens capsule (glaucoma capsularis). Arch. Ophth., 23 : 138-1(30, 1940.

485. Irvine, R. Exfoliation of the lens capsule (glaucoma capsulare). Arch. Ophth., 25 : 992-1001, 1941.

486. Itoi, M. Ueber das "Wesen der Verrostung des Eisens im| Augeninnern. Acta Soc. Ophth. Jap., 41 : Suppl., 66^-6yo, 1937; Abstract in XentralhJ. f. d. ges. Ophth., 40 : 584, 1937-38.

487. IwANOFF, A., AND ARNOLD, J. Mikroscopische Anatomic des Uvealtractus und der Linse. Graefe, A. and Saemisch, T.: Handbuch der gesammten Augenheilkunde. Leipzig, W. Engelmann, Vol. i (chapter 3), pp. 2(35-320, 1874-1880.

488. Jess, A. Das histologische Bild der Kupfertriibung der Linse, ein

Beitrag zur Frage der Linsenernahrung. Klin. Monatsbl. f. Angenh., 6S : 433-443, 1922.

489. Jess, A. Verkupferung der Zonulafasern und der teilweise abge losten Zonulalamelle bei luxiertem Kupferstar. Klin. Monatsbl. f. Angenh., j6 : 4^5-469, 192^.

490. Jess, A. Das Verschwinden der Verkupferungserscheinungen des

Auges. Klin. Monatsbl. f. Angenh., 6^ : 59-73, 1929.

491. Kaempffer, R. Coloboma lends congenitum. Arch. f. Ophth.,

48 : 558-^37, 1899.

492. Kirby, D. B. A study of standards for judging of the progress or

arrest of cataract. Tr. Am. Acad. Ophth., 32 : 203-230, 1927.

493. Kirby, D. B. Exfoliation of the most superficial lamella of the

anterior capsule of the crystalline lens. Arch. Ophth., 4 : 93-953 1930.

494. Kirby, D. B. Diseases of the crystalline lens. In Berens, C.: The

Eye and Its Diseases. Philadelphia, Saunders, 1936^, pp. 5^5-599 495. Klainguti. Cited by Vogt, reference 66z.

496^. Kleefeld, B. Methode de localisation exacte des opacites du corps vitre utilisant le focalisateur de Zamenhof et le rHractometre parallactique de Zeiss. Bull. Soc. beige d’opht.. No. 73 : 7^-85, 193(3; Opacites annulaires du corps vitre. Btdl. Soc. beige d’opht.. No. 74 : 21; 11(3, 1937.

497. Knienecker, R. Ueber einen Fall von doppelseitigen sog. Lentigobus anterior. Klin. Monatsbl. f. Angenh., 82 : 55-^4, 1929


498. Knies, M. Ueber den Spindelstaar und die Accommodation beidemselben. Arch. f. Ophfh., 23 : pt. i, 211-228, 1877.

499. Koby, F. E. Cataracte familiale d’un type particulier, se transmet tant apparement suivant le mode dominant. Arch, d’opht., 40 : 492-503, 1923.

500. Koby, F. E. Slit-Lamp Microscopy of the Living Eye, Philadelphia,

1925 501. Koby, F. E. Slit Lamp Microscopy of the Living Eye. Translated by Goulden and Flarris. London, J. & A. Churchill, 1930.

502. Koby, F. E. Biomicroscopie du corps vitre. Paris, 1932.

503. Koby, F. E. Maladies du corps vitrA Trarie d’Opht., 6 : 48, 1939.

504. Koeppe, L. Klinische Beobachtungen mit der Nernstspaltlampe und dem Hornhautmikroskop. II. Mitt. Ueber Iritis tuberculosa nebst Bemerkungen iiber therapeutische Erfolge durch Bestrahlung mit der Lampe. Arch. f. Ophth., 92 : 115-144, 1917.

505. Koeppe, L. Klinische Beobachtungen mit der Nernstspaltlampe und dem Hornhautmikroskop. III. Arch. f. Ophth., 92 : 341420, 1917.

506. Koeppe, L. Die normale Histologie des lebenden menschlichen Glaskorpers, seiner angeborenen und vom Alter abhangigen Veranderungen im Bilde der Gullstrandschen Nernstspaltlampe. i. Mittelung. Arch, f. Ophfh., 9(3 : 232, 1918; Klinische Beobachtungen mit der Nernstspaltlampe. Arch. f. Ophth., ^6 : 249; 97 ; 232, 1918.

507. Koeppe, L. Ueber Spaltlampenbeobachtungen bei Cataracta elec trica. Klin. Monatsbl. f. Angenh., G6 : 387, 1921.

508. Kolliker, a. von. Manual of human histology. London, Syden ham Society, 2 : 383, 1854.

509. Komai, T. Beitrage zur feineren Struktur der Zonulalaraelle der Linsenkapsel. Acta Soc. Ophth. Jap., 42 ; ^^6-^66, 1938; Abstract in ZentraJbJ. f. d. ges. Ophth., 42 : 570, 1939.

510. Kraupa, E, Ueber circumscripte grubenformige Ektasie am Au gengrunde. 2 ,tschr. f. Angenh., 31 : 149, 1914; Zur Kenntnis der ringformigen hinteren Glaskorperabhebung. “Zenfralbl. f. Angenh., 38 : 129-131, 1914.

511. Kraupa, E. Das Heterochromieglaukom. Klin. Monatsbl. f. Angenh., 71 ; 200, 1923.

512. Kraupa, E. Cited by Vogt, 1930-31.

513. Krause, A. C. The Biochemistry of the Eye. Baltimore, Johns Hopkins Press, 1934.

514. Krenger, O. Untersuchung von Haufigkeit und Lokalisation von Linsentrlihungen bei 401 Personen von 7-21 Jahren. Ein Beitrag zur Kenntnis des Kataraktbeginns. Klin. Monatsbl. f. Angenh., 60 : 229, 1918.

515. Kronfeld, P. C. Separation of the zonular lamella from the ec topic lens; Proceedings of the Chicago Ophthalmological Society. Am. J. Ophfh., 24 : 694, 1941.

516. Kruckmann, E. Die Erkrankungen des Uvealtraktus, Graefe Saemisch, Hdbch. d. g. A., 2 Aufl., 1907.

517. Kuhnt, H. Extraktion eines neuen Entozoon aus dem Glaskor per des Menschen. Arch. f. Angenb., 24 : 205, 1892.

518. Law, F. W. Uniocular zonular cataract. 'Brit. J. Ophfh., 16 : 385 406, 1932.

519. Lemoine, a. N., and McLeod, J. Bilateral metastatic carcinoma of the choroid. Successful roentgen treatment of one eye. Arch. Ophfh., 16 : 804, 1936.

520. Lewis, 'W. H. Experimental studies on the development of the eye in amphibia. 1 . On the origin of the lens. Rana palustris. Am. J. Avaf., 3 : 505-536, 1904.

521. Lezenius, a. Ein Fall von Naphthalincataract am Menschen. Klin. Monatsbl. f. Angenh., 40 : pt. i, 129-140, 1902.

522. Lindberg, j. G. Kliniska und undersokingar over depigmenter ingen av pupillarranden och genomlysbarheten av iris. Helsingfors, 1917.

523. Lindner, K. Zum Aufbau des Glaskorpers. Ber. ii. d. Yersamml. d. dentsch. Ophfh. GeseJhch., 50 : 86-96, 1934.

524. Lindner, K. Zur Klinik des Glaskorpers; die Zusammenziehung des Glaskorpers. Arch. f. Ophfh., 135: 332, 1936.

525. Lister, W. T. Detachment of the vitreous, in International Con gress of Ophthalmology. Am. J. Ophfh., 5 : 488, 1922.

526. Litinsky, G. a. Fine bilaterale runde symmetrische Bildung im Glaskdrper. Klin. lAonatsbl. f. Angenh., 87 : 205-208, 1931.

527. Lowenstein, a. Iritis herpetica. Klin. Monatsbl. f. Angenh., 71 : 313-322, 1923.

528. Lowenstein, A. Katarakt bein Neurodermitis. Klin. Monatsbl. f. Angenh., 72 : 1924.

529. Lussi, U. Das Relief der menschlichen Linsenkernvorderflache. Klin. Monatsbl. f. Angenh., 59 : 1-18, 1917.

530. AfAGiTOT AND Mawas. Etude sur le developpement du corps vitre et de la zonule chez I’homme. Ann. d’ocnl., 148 : 179, 1912.

531. Malting, B. Untersuchung iiber das A^erhaltnis zwischen Irido cyklitis und Glaukom. Acta Ophfh., i : 97-130, 1923.

532. Mann, I. C. Congenital absence of the lens, with special reference to an aphakic human embryo. Brit. J. Ophfh., 5 : 301-307, 1921.

533. AIann, I. C. The Development of the Human Eye. Cambridge, The University Press, 1928.

534. AIann, I. C. Development defects of the lens and their embryology. Glasgow M. /., 6 : 49-65, 1935.

535. Mann, I. C. Developmental Anomalies of the Eye. Cambridge, The University Press, 1937.

536. Marsh, E. J. Lenticonus posterior: Further study. Arch. Ophth., 8 : 804-820, 1932.

537. Mawas, j. Recherches sur I’anatomie et la physiologic de la region ciliaire de la retine. Secretion de Thumeur aqueuse. These de Lyon, 1910.

538. Mayou, M. S. The pathological anatomy of the plaques in epithelial xerosis. Ophth. Rev., 1903, p. 360.

539. McKeown, H. S. Essential progressive atrophy of iris. Arch. Ophth., 18 : 347, 1937.

540. Meesmann, a. Ueber das Bild der Subluxation und Ektopie der Linse an der Spaltlampe, nebst Bermerkungen iiber die Zonulalamelle. Arch. f. Avgenh., 91 : 261-zjy, x^zz.

541. Meesmann, A. Ueber das Verhalten der Bonulalamelle bei Lux ationen der Linse. Bcr. d. dentsch. ophth. Gesellsch., Heidelberg, 43 : 8-10, 1922.

542. Meesmann, A. Die Mikroskopie des lebenden Auges an der Gull strandschen Spaltlampe mit Atlas typhischer Befunde, Berlin, Urban & Schwarzenberg, 1927.

543. Meyer, H. Linsenmyopie durch kongenitale Mikrophakie. Klin. Moncifsbl. f. Angeiih., 84 : 525-531, 1930.

544. Michel, J. v. Ueber Iris und Iritis, Arch. f. Ophth., 27 : 17 1,

1881; Ueber die normalen histologischen Verhaltnisse und die pathologisch anatomisclien Veriinderungen des Irisgewebes, Ber. ii. d. XUI. Versainml. d. Ophth. Gesellsch., 1881, p. 106.

545. Michel, G. Beitrag zur Kenntnis der Retinitis septica, Inaug Diss. Tubingen, 1902.

546. Moore, J. E. Syphilitic iritis. Am. }. Ophth., 14 : no, 1931.

547. Motolese, Francesco La diagnosi precoce dell’oftalmia simpatica mediante la microscopia con la lampada di Gullstrand. Boll, d’ocid., 3 : 1029-1035, 1924.

548. Muller, L. Hat der Lenticonus seinen Grund in einer Anomalie der hinteren Linsenflache. Klin. Monatsbl. f. A7tgenh., 32 : 178, 1894.

549. Muller, O. Ueber Haufigkeit und Form der vorderen axialen Nahtpunktierung und der vorderen axialen Embryonalkatarakt. Arch. f. Ophth., 124 : 444-454, 1930.

530. Nettleship, E, On some hereditary diseases of the eye. Tr. Ophth. Sor. TJ . Kingdom, 29 : 57, 1909.

531. Nettleship, E., and Ogilivie, F. M. A peculiar form of hereditaiy congenital cataract. Tr. Ophth. Soc. U. Kingdom, z6 : 19120 ( 3 , 190(3.

552. Nordmann, J. Deformation acquise du cristallin par tumeur. Ophfh. Paris, No. 3 : 157- 1(30, 1930.

553. Nordmann, J. A propos de certaines formes de cataracte en rosace. Arch, d’opht., 48 : 392-402, 1931.

554. Oblath, O. Ein Fall von isolierter Nuklearmuskellahmung. Beitr. z. Anzeuh., 37 : 27, 1899.

555. Ogawa. Experimentelle Untersuckungen iiber "Wunden des Glas kdrpers. Arch. f. Atigenh., 45 : 91, 1906^.

556. Onfray, R., and Dreyfus, F. Cataracte par les phenols dinitres. Bull, et lueiu. Soc. frang. d’ophf., 50 : 118-121, 1938.

557. Ormond, A. W. Notes on the ophthalmic condition of forty-two Mongolian imbeciles. Tr. Oph'th. Soc. U. Kingdom, 32 : 6^-y6, 1911-12.

558. Parsons, J. H. Pathology of the eye, G. P. Putnam’s Sons, Vol. i, 1904; Vol. 2, 1905; Vol. 3, 190(3; Vol. 4, 1908.

559. Pellathy, a. V., AND Pellathy, S. V. Kalziumgehalt-Unter suchingen im Blutserum bei Altersstar und die Ursachen der Cataracta senilis. Klin. Monafsbl. f. Augenh., 79 ; 198-203, 1927.

560. Perera, C. a. Bilateral cyst of vitreous; report of case. Arch. Ophth., 16 : roij, 193C

561. Peter, L. Studien zur experimentellen Rontgen- und Radiumkatarakt. Arch. f. Ophth., 125 : 428-4(32, 1930.

562. Pfeiffer, C. E. Untersuchungen iiber die Haufigkeit und Lokalisation von 'Wasserspaltenbildungen seniler Linsen, nach Spaltlampenmikroskopie von 219 Augen gesunder Personen. Arch. f. Ophth., 106 : 71-91, 1921.

563. Pill AT, A. Zur Kenntnis der ringformig abgerissenen hinteren Glaskorperabhebung im lebenden Auge. Klin. Monatsbl. f. Augenh., 49 : 429, 1922.

564. PoYALEs, F., AND MoRENO, S. Hialoscopia. Arch, de oftal. hispanoamer., 34 : 47^-481, 1934.

56'j. PuRTSCHER, O. Zur Kenntnis der Vossiusschen ringformigen Triibung der vorderen Linsenflache. Centralbl. f. prakt. Augenh., 37 : 282, 1913.

5(3C Purtscher, O. Bemerkungen zur Frage der Linsen-triibung und Regenbogen-farben der Linsen-bilder bei Anwesenheit von Kupfer im Auge. Centralbl. f. prakt. Augenh., 42 : 172-175, 1918. 56^7. Rabl, Carl. Ueber den Bau und die Entwicklung der Linse. Pt.

I. Xtschr. f. -u/issensch. Zoo/., 6^3 : 49^-572, 1898.

568. Rabl, Carl. Ueber den Bau und die Entwicklung der Linse. Pt.

II. Die Linse der Reptilien und Vogel. Xtschr. f. -u/issensch. Xool.^ (35 : 257-3(37, 1899.


RabLj Carl. Ueber den Bau und die Entwicklung der Linse. Pt. III. Die Linse der Saugetbiere. Ruckblick und Schluss. XtscJjv. f. wisseiisch. Zoo/., 6y : 1-138, 1900.

570. Redslob, E. Le corps vitre, son developpement, sa structure, ses proprietes pbysico-cliimiques. Paris, Masson & cie, 1932.

J71. Reese, A. B. Melanosis oculi. A case with microscopic findings. Ain. J. Ophfh., 8 : 8^5, 1925.

572. Reese, A. B. Personal communication to the Institute of the Pres byterian Hospital in the City of New York, 1938. Cited in Clarke, C. C.: Ectopia Lentis; a Pathology and clinical study. Arch. Ophfh., 21 : 124-153, 1939.

573. Reese, A. B. Pigment freckles of iris (benign melanomas) ; their

significance in relation to malignant melanoma of uvea. Am. J. Ophfh., 27 : 2i7-22(j, 1944

574. Rehsteiner, K. Beitrag zur Kenntnis des Linsenkapselhautchen glaukom (Glaucoma capsulo-cuticulare) . Klin. Monafsbl. f. Aitgeiih., 82 : 21-3(3, 1929.

575. Retzius, G. Biologische Untersuchungen. Stockholm, Samson &

Wallin, 1893, Vol. 5.

57^. Riad Bey, M. Congenital familial cataract with cholesterin deposits. Brif. J. Ophfh., 22 : 745-749, 1938.

577. Ridley, H. Ocular onchocerciasis: including an investigation in

the Gold Coast. Brif. J. Ophfh., Monograph supplement X, 1945, PP- 57*

578. Rieger, H. Bericht fiber die von Anfang 1929 bis Ende 1931 and

der II. Universitats-Augenklinik in Wien nach Gonin oder nach Guist operierten und also ungeheilt entlassenen Falle von Ablatio retinae. Arch. f. Ophfh., 131:410, 1933; Beitrage zur Kenntnis seltener Missbildungen der Iris; Membrane iridopupillaris persistens. Arch. f. Ophfh., 13 1 : 523, 1934; Ueber die Bedeutung der Aderhautveranderungen ffir die Entstehung der Glaskorperabhebung. Arch. f. Ophfh., 13(3 : 119, 1937.

579- Rodin, F. H. Cataracts following use of dinitrophenol: Summary of 32 cases. California Wesf. Med., 44 : zy6-2j^,

580. Roemer, P. Lehrbuch der Augenheilkunde. Berlin & Wien, Urban & Schwarzenberg, 1919.

j8r. Rollet and Bussy. La cataracte noire. Arch, d’opht., 38 : ^5-8 2, 1921.

582. Rones, B. Anterior lenticonus. J.A.M.A., 103 : 327-330, 1934;

The genesis of a typical coloboma. Am. J. Ophfh., 17 : 883-889, 1934 583. Rones, B. Essential atrophy of the iris with pathological report.

Am. J. Ophfh., 23 : 1^3, 1940.

584. Rosen, E. Diabetic needles. Brif. J. Ophfh., 29 : (345, 1945.

585. Rothmund, A. Ueber Cataracten in Verbindung niit einer eigenthumlichen Hautdegeneration. Arch. f. Ophth., 14 : 159-182,

i8^8.

58^. Rumbaur, W. Ueber sternformige Reste der Pupillarmembran auf der vorderen Linsenkapsel. Kliii. Monatsbl. f. Angenh., 66 :

742, 1921.

587. Russo, A. Contributo alle cataratte congenite, ereditarie e familiari

sulla "cataracta centralia pulverulenta.” Ami. di otfal. din. ocnl., 6} : 10^-126, 1935.

588. Rydel, L. Ueber Schichtstar. Wiener Medizhial-HalJe, 4:7, 18(34.

589. Saeger, F. Hochgradige M)’'opie durch angeborene kleine Kufel linse (Mikrophakie) ohne Dislokation. Klin. Monatsbl. f. Angenh., 80 : 177-180, 1928.

590. Sallman, L, Zur Anatomie der binteren Glaskorperabhebung.

Arch. f. Ophth., 135 : 593, 193^.

591. Salzmann, M. The Anatomy and Histology of the Human Eye ball. Translated by E. V. L. Brown. Chicago, University of Chicago Press, 1912.

592. Samuels, B. Congenital Ectropium Uveae. Xtschr. f. Angenh.,

31 : 333, 1914.

593. Samuels, B. Necrosis of iris. Tr. Ophth. Soc. U. Kingdom, 49 :

421-43G 1929.

594. Samuels, B. Opacities of the vitreous. Arch. Ophth,, 4: 838-857,

1930 595. Samuels, B. Pathologic changes in the lens associated with non traumatic iritis. Arch. Ophth., 31 : 8-17, 1944.

59C Sanders, T. E. Metastatic carcinoma of the iris. Am. J. Ophth., 21 : 646, 1938.

597. Sautters, H. Myotonie und Cataracta myotonica. Arch. f. Ophth.,

143 : 1-26, 1941.

598. ScHEER, W. M. VAN DER. Cataracta lends bei mongoloider Idiotic.

Klin. Monatsbl. f. Angenh., 62 : 15 5-170, 1919.

599. ScHiLD, H. Untersuchungen iiber die Haufigkeit der lamellaren

Zerkluftung, ihre Lage und Verlaufsrichtung in der vorderen und hinteren Linsenrinde an 218 Augen sonst gesunder Personen. Arch. f. Ophth., 107 : 49-^0, 1921.

^00. ScHiRMER, O. Histologische und histochemische Untersuchungen iiber Kapselnarbe und Kapselkatarakt nebst Bemerkungen iiber das physiologische Wachsthum und die Struktur der vorderen Linsenkapsel. Arch. f. Ophth., 35 : pt. i, 220-2^8, 1889.

601. ScHLAPFER, H. Neue Beobachtungen iiber Glasmacherkatarakt.

Klin. Monatsbl. f. Angenh., 85 : 285-286', 1930.

602. Schmitt, A. Klinisch-statisticher Beitrag zur Lehre der unkompli zierten Stare. Arch. f. Ophth., 108 : 401, 1922.

603. ScHNYDER, W. F. Untersuchungen iiber die Morphologic der Strahlenkatarakt und Mitteilung iiber das Vorkommen von glasbeaserarartigen Linsentriibungen bei Eisenarbeitern, Arch. f. Ophth,, 11^:471,1925.

604. ScHOLTZ, K. Ein Fall von Echinococcus mtraoculans. Arch. f. Angcnh.^ 54 : 170, 1906'.

(305. Seefelder, R. Zur EntstehungsW'^eise der angeborenen Hornhaitsta* phylome. Wic//. kliu. Wchnschr., 37 : 996, 1924.

606. Seefelder, R. Anatomischer Refund in einem Falle von Angeborener Ektopie der Pupille mit Linsenluxation. Xtschr. f. Augenh., 25 : 353-3(31, 1911.

(307. Seefelder and Wolfrum. Ueher eine eigenartige Linsenanomalie (Lentiglobus anterior) bein einem viermonatlichen menschlichen Ebtns.. Arch, f. Ophth., ^5 : 3,20, 1907.

^o8. Silva. Zur Histologie der Irisperlen. Klin. Monatsbl. f. Augenh., 43 : 450, 1905.

(309. Silva, R. Technique de I’extraction chirurgicale des cysticerques du corp vitre. Arch, d^opht., 42 : 355-3^4, 1925.

^10. Skydsgaard, H, Cataracta electrica following electric shock, Acta Ophth,, 17 '.460-46$, 1939.

611. Smith, Priestley. Glaucoma. London, Churchill, 1879,

(3 12. SoBHY Bey, M. A contribution to the study of exfoliation of the lens capsule or glaucoma capsulo-cuticulare with anatomical preparations. Brit. J. Ophth., x6 : (^5-82, 1932.

61^. SoEMMERRiNG, D. W. Beobachtungen iiber die organischen Veranderungen in Auge nach Scani'operationen. Frankfurt/a /M., Wesche, 1828.

^14, SoRSBY, A. In; Modern trends in Ophthalmology, Edited by Ridley, F., and Sorsby A., London & New York, Hoeber, 1940, p. 147,

615, Spemann, Hans. Ueber Correlationen in der Entwickelung des Auges. Verhandl. d. aimt. Geselhch., 1901, pp. (31-79.

<3i^. Stanka, R. Akkommodative Lageveranderung von Linsentriibungen. Klin. Monatsbl. f. Augenh., (39 : 7^1-717, 1923.

617. Stein, R, Nachweis der Zonulalamelle bei spontaner Linsenluxation. Klin. Monatsbl. f. Augenh., 76 ; 75-82, 1926.

6^18. Steiner, L. Ringfdrmige Triibung der vorderen Linsenflache nach Schussverletzung der Orbita. Klin. Monatsbl. f. Augenh., 48 :484, 1910.

(3 19. Steinert, H. Myopathologische Beitrage. I. Ueber das klini&che und anatomische Bild des Muskelschwunds der Myotoniken. ^Deutsche Xtschr. f. Nervenh., 37 : 58-104, 1909.

<3 20, Stockard, C. R. The embryonic history of the lens in Bdellostoma Stouti in relation to recent experiments. A?;/. /. Anat., 6 : 5115I5 j 1906^-1907.

621. Straeten, van der and von Dyse, D. Kyste sereux epithelial sous-conjonctival du repli semi-Iunaire. Arch, d’opht., 41 : 257, 1524.

(3 22, Streiff, J. Zum myopischen und senilen Glaskorperzerfall. Klw. MonatsbL f. Augevh.^ 73 : 703-708, 1^24.; Beobachtungen und Gedanken zum Heterochromieproblem. Klin. MonatsbL f. Angenh., 62 : 352, 1919.

6^23. Streiff, J. Ueber eine untere Irismulde und uber Iristypen und Uebergange zu Anomalien. Klin. MonatsbL f. Angenh., 54 : 33-48,

(324. SwATiKOWA, A. G. Die papulose Iritis bei der Untersuchung mit der Spaltlampe, Klin. MonatsbL f. Angenh., 78 : 6^88, 1927.

(325. SziLY, A. VON. Die Linse mit zweifachem Brennpunkt, Klin. MonatsbL f. Angenh., 41 : pt. 2, 4i-(35, 1903,

6^26'. SziLY, A. VON. Uber angeborene, familiare “Ringstarlinse” nebst Hinweisen auf ihre Entstehung. Klin. MonatsbL f. Angenh., 81 : 145-1^3, 1928.

^27. SziLY, A. VON. The contribution of pathological examinations to the elucidation of the problem of cataract. Tr. Ophth. Soc. U. Kingdom, 58(2) : ^9^-660, 1938.

^28. Tepkjilaschin, a. Ueber die Star infolge chronischer Vergiftung mit Mutterkorn. Med. Oborzenje, 31 : 525, 1889.

^29. Terrien, F. Recherches sur la structure de la retine ciliare et I’origine des fibres de la zonule de Zinn. Arch, d^opht., 18 : 353, 1898.

^30. Terrien, F. Mode d’insertion des fibres zonulaires sur le cristallin et rapport de’ ces fibres entre elles. Arch, d’opht., 19 : 230-237, 1899.

6'3i, Terrien, F. Cataractes congenitales et vestiges de la membrane pupillaire. Arch, d’opht., 34 : 230-233, 1914-1913.

^32. Terry, T. L. Fibroblastic overgrowth of persistent tunica vasculosa lentis in infants born prematurely; studies in development and regression of hyaloid artery and tunica vasculosa lentis. Am. J. Ophth., 23 : 1409, 1942.

(333. Terry, T. L. Retrolental fibroplasia in premature infants, further studies on fibroplastic overgrowth of persistent tunica vasculosa lentis. Arch. Ophth., 33 : 203, 1943; also Tr. Am. Ophth. Soc., 42 : 383, 1944.

6^34. Terry, T. L. Ocular maldevelopment in extremely premature infants; retrolental fibroplasia: general consideration. J.A.M.A., 128 : 382-384, 1943.

(333. Teulieres, M., and Beauvieux, j. Tumeurs de I’iris. In Traite d’ophtalmologie, 3 : 66, 1939.

6 }6. Thiel, R. Ein Beitrag zur Spaltlampenmikroskopie des Auges im ultra violetten Licht. Xtschr. f. Angenh., 38 : 8^-91, 192^.

(337. Thompsen, j. Topische Krampfe in willkurlich beweglichen Muskeln in F’olge von ererbter psychischer Disposition, Arch. f. PsychiaL, 6 : 702-7183 1876.

(>38. ToulanTj P- Un cas de carcinome metastatique de I'iris. Arch, d’ophf., 3 : 443 19 1

^39. Trantas. Pesions seniles de la capsule anterieure du cristallin et du bord pupillaire. Arch, d’ophf., 46 : 482-491, 1929,

^40. Troncoso. Vesicule flottante du vitre. Ann. d’ocni., 130 : 341,

1903- . , t

<341. Troncoso, M. U. Microanatomy of eye with slit-lamp microscope;

comparative anatomy of ciliary body, zonula and related structures in mammalia. Ant. J. Ophth., 25 : 1-3 1, 1942.

^42. Tscherning, M. H. Physiologic optics. Ed. 4. Philadelphia, Keystone Publishing Co., 1924.

^43. Tyson, H. H. Lenticonus posterior. Arch. Ophth., 57:38-40, 1928.

^44. Uhthoff, W. [Discussion of Bleisch’s case] Berlin. kJin. Wchnschr. 5<> : 117, 1919 645. Vogt, A. Analytische Untersuchungen iiber die Fluoreszenz der

menschlichen Linse und der Linse des Rindes. Klin. Monafsbl. f. Angenh., 51 : pt. i, 129-156, 1913.

646. Vogt, A. Klinischer und anatomischer Beitrag zur Kenntnis der

Cataracta senilis, insbesondere zur Frage des subkapsulaten Beginnes derselben. Arch, f. Ophth., 88 : 329-369, 1914.

647. Vogt, A. Ueber Farbenschillern des vorderen Rindenbildes der

menschlichen Linse. Klin. Monatsbl. f. Augenh., 59 : 518-526, 1917.

648. Vogt, A. Der Altersstar, seine Hereditat und seine Stellung zu

exogener Krankheit und Senium. Xtschr. f. Angenh., 40 : 123137, 1918.

649. Vogt, A. Beobachtungen an der Spaltlampe iiber eine normaler weise den Hyaloidearest der Hinterkapsel umziehende weisse Bogenlinse, Arch. f. Ophth., 100: 349-356, 1919.

650. Vogt, A. Lehrbuch und Atlas der Spaltlampenmikroskopie des

lebenden Auges. Berlin, J. Springer, 1921.

651. Vogt, A. Weitere Ergebnisse der Spaltlampenmikroskopie des vor deren Bulbusabschnittes, III. Angeborne und friih erworbene Linsenveranderungen. Arch. f. Opth., 107 : 196-240, 1922.

652. Vogt, A. Weitere Ergebnisse der Spaltlampenmikroskopie des vor deren Bulbusabschnittes, VIII. Abschnitt iiber die pathologisch veranderte Iris. Arch. f. Ophth,, 11 1 : 91-127, 1923.

^ 53 - Vogt, A. Weitere Ergebnisse der Spaltlampenmikroskope des vorderen Bulbusabschnittes, VIII. Abschnitt iiber die pathologisch veranderte Iris. Arch, f .Ophth., 112 : 89-132, 1923.

6^4. Vogt, A. Neue Beobachtungen iiber menschliche Krystallinsen mit doppeltem Brennpunkt. Xtschr. f. AngenJj., 50 : 145-152, 1923. (355, Vogt, A. "Wahrscheinlichkeitsbeweis fiir den Helmholtzschen Akkommodationsmechanismus. Klin. MonatsbL f. Aiigenh., 72 : 412413, 1924.

6^6. Vogt, A. Ein neues Spaltlampenbild des pupillengebietes Hellblauer Pupillensaumfilz mit Hautschenbildung auf der Linsenvorderkapsel. Klin. MonatsbL f. Augenh., 75 : 1-12, 1925.

(357. Vogt, A. Ein neues Spaltlampenbild: Abschilferung der Linsenvorderkapsel als wahrscheinliche Ursache von senilem chronischem Glaukom. XtscJor. f. Angenb., 58 : 379-381, 192(3.

(358. Vogt, A. Der histologische Befund bei Kapselhautchenabschilferung und Kapselhautchenglaukom (Glaucoma capsulocuticulare) . Xfschr, f. Angenb.^ 66 : 105-10^, 1928.

(359. Vogt, A. Neue Falle von Linsenkapselglaukom (Glaukom capsulaire. Klin. MonatsbL f. Angenb., 84 : 1-2, 1930.

660. Vogt, A. Cataracta disseminata subcapsularis glaukomatosa. Klin.

MonatsbL f. Angenb., 85 : 586'-587, 1930.

661. Vogt, A. Aplasia und Hypoplasia lentis (Aphakia congenita).

Klin. MonatsbL f. Angenb., 87 : 257-258, 1931.

661. Vogt, A. Lehrbuch und Atlas der Spaltlampenmikroskopie des lebenden Auges. Berlin, J. Springer, 1930- 1931, 2 vol.

661. Vogt, A. Lehrbuch und Atlas der Spaltlampenmikroskopie des lebenden Auges. Berlin, J. Springer, Vol. 2, p. 348, 1931.

664. Vogt, A. Ueber zystoide Retinadegeneration und die begleitenden Liniennetze, und iiber die optischen Bedingungen der Sichtbarkeit der Zysten. Klin MonatsbL f. Angenb., 92 : 743-747, 1943.

66y Vogt, A., and Lussi, L Weitere Untersuchungen iiber das Relief der menschlichen Lensenvorderfache in Alter. Arcb. f. Opbtb., 100 : 157-1^7, 1919.

666 . Vossius, A. Ring-shaped opacities on the anterior surface of the

lens after contusions of the eye. Arcb. Opbtb., 35 : 56^(3-5(37, 1906.

667. Wagenmann, a. Verletzungen des Auges mit Berucksichtigung

der Unfallversicherung. In Graefe, A., and Saemisch, T.: Handbuch der gesamten Augenheilkunde. Ed. 3. Leipzig, W. Engelmann, Vol. 2, p. 370, 1915.

668 . 'Walls, G. L. 1931. Cited in "Walls and Judd, 1933.

669. Walls, G. L. The pigment of the vertebrate lens. Science, 91 : 172,

1940.

670. Walls, G. L., and Judd, H. D. Intra-ocular colour-filters of

vertebrates. Brit. J. Opbtb., 17 : 641-675, 1933.

671. Walter, F. Ueber traumatischen Schichtstar. Inaug. Dissert Ros tock, 1917, p. 23.

672. Waring, J. J., Ravin, A., and Walker, C. E. Studies in dystrophic myotonica; Clinical features and treatment. Arch. Int. Med., 65 : 7^3-799> ^ 940 ^73. Weiss, L. Ueber den an der Innenseite der Papille sichtbaren Reflexbogenstreif und seine Beziehung zur beginnenden Kurzsichtigkeit. Arch. f. Ophth., 31 -.239, 1885.

674. Weissenbach, Karl. Untersuchungen iiber Haufigkeit und Lokalisation von Linsentriibungen bei 41 1 mannlichen Personen im Alter von i6-z6 Jabren. Kim. Monatsbl. f. Angenh., 59 : 327537> 1917 ^75. Werner, L. Coloboma of optic nerve. Ophth. Rev., 22 : 80, 1903. 6j6. Whalman, H. F. Dinitrophenol cataract. Am. J. Ophth., 19 : 885-888, 1936.

6'77. Whitehead, A. L. Ocular tuberculosis. Brit. J. Ophth., 6 : 529537, 1922.

678. WiLMER, W. H. Cyst of the uveal layer of the iris at the pupillary

margin in a case of posterior synechiae with secondary glaucoma. Am. J. Ophth., I : i<32-i^7, 1929.

679. WiNTERSTEiNER, H. Ueber traumatische Iriscysten, Ber. iiber 28.

vers. d. ophth. Gesellsch. Heidelberg, 1900, p. 4.

^8o. Wolff, E. A Pathology of the Eye. Philadelphia, Blakiston, 1935. 6% I. WoLFRUM, M. Zur Entwicklung und normalen Struktur des Glaskorpers. Arch. f. Ophth., 65 : 220, 1907.

682. WoLFRUM, M. Ueber Ursprung und Arnsatz der Zonulafasern im

menschlichen Auge. Arch. f. Ophth., 6j : 307, 1908.

683. Zavalia, a. U., and Oliva, R. O. Two cases of anterior lenti globus. Arch, oftal. de Buenos Aires, 14 : 848, 1939.

684. Zeeman, W. P. C. Diseases of the iris, ciliary body, and posterior

aqueous chamber. Cited in The Eye and Its Diseases. Edited by Conrad Berens, Philadelphia, Saunders, 193C P* 603-6^73.

^85. Zentmayer, W. Primary sarcoma of the iris. Arch. Ophth., 5 ; 219, 1931.

686. ZiNN, J. G. Descriptio anatoraica oculi humani, iconibus illustrata, Gottingen, A. Vandenhoeck, 1755.




Cite this page: Hill, M.A. (2019, September 24) Embryology Book - Biomicroscopy of the eye 2. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_Biomicroscopy_of_the_eye_2

What Links Here?
© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G