Book - Biomicroscopy of the eye 2-24

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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.

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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.





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Historic Embryology: 1906 Eye Embryology | 1907 Development Atlas | 1912 Eye Development | 1912 Nasolacrimal Duct | 1917 Extraocular Muscle | 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
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24 Developmental Lens Changes

Congenital Anomalies of the Lens

The universally found rests of the vascular tunic thus far discussed have been considered “physiologic” in nature. Other anomalies of the lens (principally ectodermal) grossly deform the lens either in size, shape, or position or by the formation of opacities (cataracts) and interfere with function."


In this discussion only the developmental (congenital and early acquired) lens changes will be considered. The progressive juvenile forms of coronary cataract (cataracta cerulea and viridis) and opacities associated with presenile and senile cataractous changes, which in turn may be considered also as developmental in the sense that they are probably genetically determined, will be considered under a special heading. It should be pointed out that except for their frequency and unless a thorough history and pedigree is obtainable, it may not always be possible to separate developmental cataract from morphologically similar instances of environmental causation. In other words it may well be that morphologically the pattern of lens opacities is governed more by temporal factors than by etiological ones. So that during the various periods of life lens changes, whether of genetic or environmental origin, appear similar. An example of this is seen in zonular cataract (cataracta parathyreopriva) and in diabetic cataract. Cases have been recently reported in Australia where rubella acquired by the mother during early pregnancy results in a congenital cataract in the offspring." In toxoplasmosis also, congenital defects of the lens may result which morphologically may be very similar to developmental cataract of hereditary origin.


  • I should like to quote verbatim the opening paragraphs of Ida Mann's description of developmental cataracts, since it so beautifully summarizes the subject: "It is to be remembered that at no normal stage of development is the lens other than transparent. This property it shares with all other embryonic tissue (except the blood and the pigment cells) in early stages and it retains this property when, owing to more and more complicated differentiation, the other tissues have become opaque. Even in the lens the earliest formed part (the central dark interval) remains the most transparent (optically empty) throughout life, while the later formed secondary lens fibers show zones of increasing relucency and fluorescence until the most superficial fibers formed in extreme old age show opacities so often that these might almost be considered normal. Therefore all congenital lens opacities are pure aberrations and can never be arrests. Any opacit}’’, whether total, or so small that it can only be seen by focal illumination with the slit lamp, is technically a cataract. Cataracts may be present at birth or may form during infanq' or adolescence. In either case they are developmental and this term, rather than congenital, should be used for them, since in the lifelong growth of the lens fibers the moment of birth is only an accident. Even changes of commencing senilitj’ .are not sharply marked off from growth processes.


It is interesting to note that all the above (congenital, juvenile, presenile, and senile) developmental opacities seem to have a special predilection for certain specific zones in the lens. In other words, the different zones of the lens (cortex, adult nucleus, fetal nuclei) react at a certain time during the course of development to influences leading to cataract. However, these cataracts morphologically have different forms. It will be seen that not only do these opacities lie in the above-mentioned zones but in most instances, depending on the stage of lens development, they are found in specific parts of these zones and have individual distinguishing forms biomicroscopically. From this it could be concluded that during certain periods of life not only the main zones but even the subzones show specific changes which are governed by heredity, called "idiokinetic” changes. The same effect may result from the influence of noxious agents. In addition to the location-specificity of these opacities, there also is a relationship between morphology, location, and chronologic development, At the present time less , is known about the chronology of development than the others.


The chronologic factor (time of inception) , as regards the character of the anomaly, is more important whether the underlying causal factors be hereditary (genetic) or environmental (nutritional, toxic or mechanical) . In either case when these forces act early, gross malformation or disturbance results. Later, after the pattern of the lens structure has been established, the resulting defects can only be an aberration, which may be simple, complicated, or may form "lesions resembling the effect of disease.” In environment defects, i.e., those resulting from pressure or toxins, gross deformities of the lens may result if their action is very early because (not unlike the retina) the tissue instead of reacting in the ordinary way tends to undergo changes comparable to necrosis. According to von Szily:'*' "The early stages of idiokinetic malformations (hereditary) of the lens now permits of recognizing divergences from normal development especially in two directions. In one group we have to do with anomalies in the mutual delimitation of the two main sections of which the embryonal lens is composed, i.e., of epithelium and fiber components. The second group which indirectly also sets in a little later, represents disturbances in the formation of the sutures of the lens. Both processes lead to a more or less serious disturbance of the internal structure of the lens, and are mostly secondarily connected with disintegration of the lens sections affected.” In environmental cataract (congenital or acquired) the alteration (e.g., as demonstrated by cataractous opacity) is primary, and any morphologic' deformity occurring in consequence of it is secondary. However, clinically, as mentioned above, in the absence of a satisfactory pedigree recording repeated instances of the anomaly, differentiation of environmental and hereditary lenticular alterations may be uncertain.


  • Most of these were total in character and were associated with microphthalmos. Goar and Potts reported seven cases all of which were accompanied by other defects, "usually congenital heart lesions, poorly developed musculature, and retarded mentality'’ The cataracts are typical in that the embryonal nucleus which develops soon after the fibers are laid down is affected.” There were no indications of fetal iritis (synechiae).


At birth, the embryonal Y-sutures are situated closely behind the capsule. Although during the first years of life there are already indications of those portions of the lens that will later develop into the adult nucleus and cortex, it can be deduced that opacities occupying the central (embryonal and fetal parts) of the lens (e.g., anterior axial cataract, stellate cataract, polar cataract,f and cataracta centralis pulverulenta) are formed during fetal life, and zonular cataract probably develops just before or after birth.^

The congenital opacities above-mentioned or those which develop just after birth are restricted to well-defined zones and do not progress; thus, they appear the same morphologically in age as in youth. We know little concerning the time of onset of the so-called "presenile” opacities (e.g., coronary and cerulean) , which are somewhat progressive, although they seem to start at about the time of puberty. A great deal more detailed study - especially statistical - will be necessary before the time of onset of most of these opacities can be established.


  • The reader is advised to read the monograph published by von Szily in 1938.
  • Polar cataract (subcapsular) becomes separated from the nucleus by the ingrowth of secondar)' lens fibers.
  • The larger size of this form of cataract - 4 to 7 mm. in comparison with the size of the lens during fetal life - speaks for a later development.


Following is a classification of the various congenital anomalies of the lens;

L Congenital lens alterations due to gross changes in size, shape, or position

A. Congenital aphakia

B. Microphakia

C. Lenticonus, anterior and posterior

D. Lentiglobus

E. Coloboma lentis

F. Ectopia lentis and spherophakia

11 . Congenital developmental lens opacifications

A. Polar and capsular cataract (anterior and posterior)

B. Opacities in the vicinity of the fetal Y-sutures

1. Anterior axial embryonal (fetal) cataract (Vogt)

2. Stellate suture cataract (anterior and posterior)

C. Zonular cataract (lamellar)

D. Cataracta centralis pulverulenta (Vogt)

E. Rare forms of congenital axial cataracts

1. Cataracta pisciformis (Vogt)

2. Corralliform cataract

3. Axial fusiform cataract

4. Spear cataract

5. Floriform cataract

It should be pointed out that most of these opacities are located predominantly in the axial regions. Hereditar)' opacities, e.g., coronary, cerulean and the so-called "presenile opacities (sec page 1093) which develop after pubertj' are located more peripherally (equatorial).


F. Rare forms of congenital cataract affecting a greater portion of the lens

1. Disc-shaped or ring form cataract

2 . Congenital morgagnian cataract

Gross Changes in Size Shape, or Position of the Lens

Congenital Primary Aphakia. This very rare condition must be differentiated from congenital secondary aphakia in which partial or complete solution of the lens has occurred after it has already been formed. According to some investigators the former is only found associated with gross malformations, e.g., anophthalmia or severe microphthalmia. Whether or not it can occur in eyes not associated with other severe defects has not been established.


According to Vogt's cases congenital aphakia (hypoplasia lentis) occurred in association with microphthalmia, microcornea, nystagmus and central corneal opacities. The possibility of intrauterine infection with corneal ulceration must be considered, as has been shown b} Seef elder. But Vogt questions this etiology in his 3 cases involving 6 eyes because of the symmetrical leukomata and their regular bandlike connection with the axial pupillary region, in that it could hardly be possible that in all 6 cases the lens degenerated in the same way. Anatomically v. Helmholtz showed that congenital aphakia occurs (having demonstrated it in a microphthalmic and hydrophthalmic eye) . Following von Hess, Vogt believed that the disturbances in separation of the primary lens vesicle could be the cause of this anomaly. Early Regeneration and aplasia of the lens could easily hinder the development of the cornea resulting in microcornea. In two of his cases ultraviolet light projected into the pupil gave no lens fluorescence. In one of his cases there was aplasia of the iris (only the mesodermic layers were present) with synechiae extending to the cornea and to the membrane in the pupillary periphery. In this case the lens was substituted by a band, consisting of scar tissue surrounded by a delicate film. After iridectomy the finely pigmented zonule fibers were seen overlying the delicate membrane. Optic section through the membrane revealed a double line, the outer brown (zonule) , and the inner or deeper gray (anterior limiting layer of the vitreous). These eyes are highly amblyopic and because of the nystagmus biomicroscopic examination is difficult.


Secondary aphakia occurs more frequently in otherwise normal eyes but more often it is associated with microcornea and other malformations. It likewise is thought to be due to primary failure of development in surface ectoderm. In these cases some vestige of degenerated lens matter and capsule (which may be wrinkled or shrunken and to which zonule fibers are attached) are always found. Secondary invasion by repair tissue and vascularization may further complicate the picture. Except for the microcornea or other defects, this picture is similar to cases occasionally seen in adults in whom, owing to long-standing disease the lens eventually becomes shrunken, calcareous and vascularized.


Microphakia (spheropha/da, or lens rotunda") . This anomaly is an example of sudden arrest in growth of the lens, which may occur without any apparent defects, except in the zonule."' Whether this anomaly is directly the result of a genetically determined inhibition of the lens anlage, loss of growth energy, or aplasia of the zonule is still unknown. According to Vogt, his biomicroscopic findings of torn and absent zonular fibers and such pathologic changes as pigment deposits indicate that in microphthalmos as well as in ectopia the underlying factor is not abnormally long zonular fibers (a view generally held) but rather the presence of rudimentary weak ones. This inherent weakness in the zonule is conducive to stretching and tearing of the brittle fibers. Since there is not sufficient power to exert tension upon the lens, normal development of the flattened shape is impeded. As a result the lens retains its spheric (embryonic) form. Because of the nature of the zonular changes further consideration of microphakia and congential ectopia from the standpoint of biomicroscopy will be found in the chapter on the zonule (page 1341).


It has been pointed out that in this condition the diameter of the cornea is normal or commonly is slightly enlarged. In cases of microcornea interference with the development of the lens is commonly seen, e.g., congenital cataract. It is still unknown ^vhether genetically or mechanically there is any relationship behv'een the size of the cornea and spherophakia.


Lentiglohus {Len ti conus) . The terms "lentiglobus” and "lenticonus” describe an anomalous localized deformity of the curvature of the anterior or posterior lens surface. It is characterized by the presence of a conical or bullous projection or ectasia. When the protruberance is globular or hemispherical, it is known as "lentiglohus" Actually uncomplicated (true) protrusions are globular in shape while most of the complicated ones are conical.


Since the introduction of the biomicroscope, more of these cases have been brought to our attention, especially the posterior lentigJobus (anterior lentiglohus and lenticonus being more rare). According to von Szily, only those cases in which the protrusion occurs without rupture of the capsule should be considered as pure forms of lenticonus or lentiglohus.

Vosterior Lentiglohus. In most instances globular projections, predominantly uniocular, have been found in the neighborhood of the posterior pole and particularly in the region of the arcuate line. Biomicroscopic descriptions of these cases have been given by many authors (Rydel, Vogt,®"*^ Butler,®^^ Whiting, March, Tyson and Pellathy . In Butler’s case a rosette-like opacity on the posterior surface of the infantile nucleus (future adult nucleus ?) was connected to a smaller posterior disk by a stem resembling in shape a collar button. It was located at the posterior pole. He also reported a case of lenticonus internum or lenticonus perinuclearis posterior, apparently an abortive case in which the posterior capsule was unaffected. There was an unusual backward double bulge of the posterior adolescent nucleus. This appearance was caused by a concave depression in the axial part of the protrusion of nucleus. The area of the bulge was diffusely opaque. In March’s case there was no opacification in the globular protrusion of the posterior capsule. Tyson described a case (unilateral) which was somewhat flattened or saucer-shaped (opaque). The diameter of the protrusion was about one-fifth that of the lens and the corrected vision was 6/30.


The degree of protrusion may be rudimentary or marked. In most cases, some degree of opacification is present, although cases have been described in which a hemispheric protuberance was found to be transparent or clear in an otherwise normal lens. The location and extent of the opacity varies from case to case. An almost constant finding is a sharp and circularly rounded anterior margin of the conus. This results in a vivid ring reflex caused by a reflection from the capsule at the peripheral rim of the cone (Fig. 375 A). It is difficult to see this unless the pupil is dilated. The direction of the capsular curve suddenly becomes convex in a frontal direction before it begins to bulge dorsally. The sharp circular ring (reflex) results from specular reflection at this point and may appear doubled, if observed binocularly, since specularly reflected rays from one given point will fill only one eyepiece at a time. The reflex ring surrounding the protuberant area can at times be seen macroscopicall)’" or with the ophthalmoscope and when the conus is not clouded b)'^ opacities, it has been described as an oil droplet witliin the lens. It will appear reddish in the light reflected from the fimdus. This form of retro -illumination can also be obtained with the biomicroscope if the beam is directed from the temporal side, and the conus can be viewed in the red light reflected from the nasal fundus. In addition Vogt has described scissors reflexes, i.e., two reflexes located behind the lenticonus which come from the opposite sides of the walls. These can be made to cross one another by moving the direction of the beam.


The presence of the ring reflex is diagnostic because it proves that a sudden change in capsular curvature is present. The sudden change in curvature is also directly visible in optic section (Fig. 375 A, B). In this way when the conus is clear or sufficiently translucent, it will be seen that the outer zones of discontinuity follow the abnormal curve. However, the inner fetal nucleus is never involved and will be found intact in its normal location. The opacity itself may outline the bottom of the cone posterior capsule and in some cases it will be seen that it extends laterally. The part outlining the walls of the protrusion may also difier in consistenc} and density, from the central part forming its base. Thus, when the opacity is viewed frontally in diffuse Hglit it may appear as a small central circular area, surrounded concentrically by an opaque band. Also one may find an opaque layer of opacity in optic section within the conus in front of those described above but located more centrally at the level of the anterior adult nuclear stripe (Fig. 375 A, B) . The reduplication of layers reminds us of the structure of polar cataracts. Between these layers of opacity the cortex will show varying degrees of increased relucency. In other cases, a small opacity may lie within the conus without touching or involving the posterior capsule, but it may contact the posterior adult nuclear stripe or, in very young individuals, one of the stripes outside the inner fetal nucleus (which later are thought to fuse forming the adult nuclear stripe) . According to the descriptions of cases in the literature most will fall under the heading of lentiglobus. It may be that lenticonus has a different pathogenesis than lentiglobus. Many suggestions by several writers have been proposed for the explanation of the pathogenesis of this anomaly. The fact that the fetal nucleus remains intact would indicate a late or postnatal development. Added to this is the frequent involvement of the zone of discontinuity which corresponds to the adult nuclear stripe formed just before or after birth. In most cases the site of the bulge is at the pole in the neighborhood of the arcuate line. This is temporal to the insertion of the hyaloid artery and might indicate that the conus does not result from direct traction of the hyaloid vessel on the posterior surface of the lens. In one of his cases, Vogt found the vestige of the hyaloid artery attached just at the nasal edge of the conus. (Normally the hyaloid remains are found within the arcuate line and not at its edge.) He theorized that if the development of the capsule in the region of the arcuate line (which normally according to Drusault shows a development different from the rest of the capsule since it attains its full thickness in the fourth fetal month) was faulty (weak or torn) it might give way to the intralenticular growth pressure and herniate. Bach, basing his conclusion on a histologic demonstration of the attachment of a persistent hyaloid vessel to a posterior lenticonus, believed that the attachment caused a weakness or rupture of the posterior capsule with resulting herniation.


Von Szily (1928) found that detritus collects behind the lens during its development and that this is later removed by the vasa hyaloidea. Failure of absorption of this material might also be a factor in interfering with the normal development of the capsule and hence might induce a herniation. Others have attributed it to an unequal traction of the zonule associated with inflammation or even accommodative effort. The cases studied were complicated and hence probably fall into the group classified as lenticonus rather than lentiglobus.


Anterior Lenticonus and LentigJobus. Comparatively few cases (about 12) of this anomaly of the anterior face of the lens have been reported in the literature, and only in one or two instances have they been studied with the biomicroscope. Only about half of them were considered to be congenital. In one case cited by Bellows (Zavalia and Oliva®®^) there seemed to be a recessive hereditary transmission; two sons of a consanguinous marriage had anterior lenticonus (bilateral in one) . Knienecker reported a case (also cited by Koby) of a bilateral anterior lentiglobus. The axial protrusions - ^which measure from 3 to 4 mm. in diameter and 2 mm. in height - were clear, and there were no other associated anomalies. The fetal nuclei were intact, and only the cortex was involved in the defect. In the region of the protrusion, retinoscopy revealed high myopia { - 20 . D ) . The peripheral unaffected parts were emmetropic. Feigenbaum also reported a case (unilateral) of anterior lentiglobus in a 1 2-year-old boy in which the fetal nucleus was involved. Many suggestions have been advanced to explain the pathogenesis of anterior lentiglobus. Among them are a faulty separation of the primary lens vesicle, a weakness of the anterior lens capsule with resulting herniation owing to the internal pressure of lens growth, and a lack of adequate or regular zonular tension because of an anomalous insertion or absence of the zonular fibers."' The fact that in some cases the protrusion developed later in life and was progressive was explained, according to Bellows, by Marsh and Feigenbaum as a result of accommodative strain in the presence of a congenitally weak capsule. In addition pathologically Seef elder and Wolf rum (1907) and Rones (1934) found that the anterior bulge of the lens was made up of a lenticular-shaped mass of homogenous-staining material behind a normal capsule and epithelium. This material, separating the latter from the underlying lens fibers, could easily act as deterent to the ingrowing fibers. Pressure of the neighboring growing fibers could then cause a herniation or ectasia. On the basis of what is seen in certain lower forms (fish and primitive toads) in which the lens appears to bulge through the pupil as though the iris were pressing it back peripherally, Mann has hypothecated that "it is possible that some such deforming stress may have occurred in fetal life owing to a too-rigid pupil, and the lens may have been permanently moulded.” Through the courtesy of Dr. Ehrlich, I saw a lo-year-old boy who had a small polar opacity in the left eye (vision 20/30) and who had what appeared to be a progressive anterior lenticonus in the right eye (vision: hand movements). In this completely cataractous eye in the axial region, the base of the anterior cone was outlined by a circular band, which under high power was seen to be formed by small yellowish white dots (Fig. 376 ) . The intenor of the protrusion was composed of fine opaque fibers arranged in irregular layers. Later the top of the globular protrusion spontaneously ruptured and some of these fine white fibers (opaque lens fibers) extended from it with their distal ends floating freely in the anterior chamber.



In the latter case should we not expect to find spherophakia or ectopia lentis?



Fig. 376. Anterior lenticonus. A. Diffuse view. b. Before rupture, c. After rupture of the cone. B and C are optic section views. (After Ehrlich.)


Fig, 377. Colobomas of the lens. Types of defects, a. Notch. B. Triangle, c. Elipse. d. Segment.

E. Spindle. (After Kaempffer.)



Coloboma of the Lens. This by itself is a very rare anomaly and in most of the reported cases was associated with other defects, especially ectopia lentis and spherophakia. Modern interpretation of its pathogenesis, based on clinical as well as experimental evidence, seems to point to secondary defects or absence of the zonular fibers. In practically all cases observed biomicroscopically the zonule or its remains seen in the colobomatous area was pathologic (fragile, torn, or sprinkled with pigmented or whitish deposits) . As previously mentioned the normal flattened axial development of the outer portions of the lens depends in part on the zonular tension. Without this (as seen in spherophakia and ectopia) the lens becomes less flat or spherical. However, it seems in some cases that an added factor of some kind would be necessary to produce an actual coloboma. According to Mann (after Hess and others) persistence of the capsulopupillary vessels could cause a zonular defect and that this, in view of the localized absence of zonular traction, would lead secondarily to a colobomatous defect in the lens. Rones suggests that since the growth rate of the lens is not constant, loss of inherent energy in a particular zone ma} be a factor.

Depending on the extent, colobomas may be small or may involve as much as one-third of the lenticular circumference (Fig. 377)


The smaller ones usually appear as notches while the larger ones may have an elliptical or crescentic shape or a segment defect as if the lens was cut by a chord of the lens circumference."* Coloboma lentis occurs more frequently in the lower part of the lens and when small requires dilatation of the pupil for its detection. In other cases it may be associated with coloboma of the iris and choroid. As in slight subiuxations, small peripheral notches may not disturb vision and, unless the pupil is dilated, may be missed. Larger ones may result in aphakic hypermetropia or (owing to increase in spherical shape of the lens) lenticular myopia. The frequent association with opacities (zonular or lamellar cataract, coronaris, etc.) may further affect vision.

Developmental Cataracts

Capsular And Polar Cataracts

(Anterior And Posterior)

Capsular cataracts or those just limited to the capsule are rare. With the narrow beam it will be seen that they do not invade the cortex deeply, but because of their thickness they alter the curvature of the lens by protruding slightly toward the anterior chamber (Plate LX, Figs. 3, 4, 5, <3). In contradistinction to polar cataracts they may be found outside the polar regions. The strictly hereditary forms must be differentiated from those acquired pre- or postnatally through inflammation or trauma. Capsular cataracts may be white, but frequently they are sprinkled with small pigment granules which may be found on the surrounding capsular areas as well. As in the case of polar cataracts, capsular opacities may have filaments attached to them. Filaments derived from the pupillary margin would strongly suggest inflammatory synechiae; while those from the lesser circle, a developmental aberration. As a rule capsular opacities are small. According to Koby most of these capsular opacities are produced by old synechiae of iritis occurring before or after birth. Vogt described an unusual case in which a capsular cataract developed after a perforating corneal injury in an eye that previously had welldeveloped remains of the pupillary membrane.


According to RaempfFeir the size and shape of the defect depends on the number of the weakened, stretched, or absent zonular fibers. Evidently defects in the more axially inserted fibers (anterior and posterior zonuiar fibers especially the stronger anterior ones) ye liable to cause greater coiobomatous defects than the shorter equatorial ones which insert more peripherally. In the latter case depending on the size of the area involved a small notch or larger elliptical defect will result. When both anterior and posterior fibers are entirely absent in an area then retraction of the elastic lens capsule will cause a larger segment-like coloboma extending more axialward.


PLATE LX


Fig. 1. Anterior polar and capsular cataract with reduplications. Pupillary membranes. '

Fig. 2 . Same as Figure i by direct focal illumination.

Fig. 3. Capsular opacity attached to the iris. Diffuse illumination.

Fig. 4. Same as Figure 3 by direct focal illumination. Ffigh power.

Fig. 5. Capsular opacity. Diffuse illumination.

Fig. 6. Capsular opacity, with small imprint. Direct focal illumination.



An interesting phenomenon, greatly stressed by Vogt (1917), was the presence of a shagreen-free halo surrounding capsular opacities (Vogt's sign) . He found this halo in every type of anterior capsular cataract whether congenital, or acquired through trauma or disease. It is not seen with capsular deposits, e.g., remains of the pupillary membrane. Evidently it is caused by a "level” change (characteristic of capsular opacities, or of polar cataracts involving the capsule) in the shagreen field so that specularly reflected rays at this place do not reach the observer’s eye. However, by altering the direction of illumination and observation, it is possible to obtain a shagreen in the halo (previously nonreflecting) area. With this maneuver Vogt was able to find microscopic anterior polar cataracts in the form of- dots measuring from 0.05 to i mm. Two points prove that these little dots were genuine anterior polar cataracts: (i) they were found in individuals whose siblings had anterior polar cataracts or in whom the fellow eye showed one. (2) these dots showed shagreen-free dark halos.


Polar cataracts are situated subcapsularly and may or may not involve the lens capsule. In either case they tend to extend deeper into the lens but not beyond the adult nucleus. In the literature the distinction between capsular cataracts and polar cataracts is not always clear. For example, capsular cataracts that (in the polar region) project into the anterior chamber in the form of a cone or pyramid are known as pyramidal capsular cataracts even in the presence of an imprint in the cortex. I believe that for the sake of clearness the term capsular cataract should be reserved for opacities involving the capsule only and that the complicated ones in which the capsule and the subcapsular areas are affected (in the polar regions) should be known as polar cataracts.


Most of the pyramidal cataracts are of the polar type. Here we see a combination of capsular and subcapsular cataract, in which the capsular part may at times be overdeveloped (Plate LX, figs. 1,2). In some cases depending on the time of origin a pyramidal opacity may develop beneath the capsule, the apex just touching it or the apex of the pyramid may be directed centrally. Whether projecting anteriorly from the capsule or within the lens subcapsularly, these pyramids are generally not solid structures but are formed by terraced layers, starting as a small layer beneath the capsule, each succeeding disk increasing in diameter as the base is approached deeply (Plate LXI, figs, i, 2, 3) . It is easier to explain the formation of these terraces when they occur within the lens (i.e., by the ingrowth of new fibers) than those occurring in the projections that extend pyramidally from the capsular surface into the anterior chamber. One might imagine that owing to a weakness in the capsule, the new fibers beneath the capsule growing in from all sides cause successive layers to herniate because of intralenticular pressure.


PLATE LXI


Fig. I. Anterior subcapsular polar cataract (pyramidal). Diffuse illumination. Fig. 2. Same as Figure i. Direct focal illumination. Ffigh power.

Fig. 3. Anterior polar cataract.

Fig. 4. Posterior polar and capsular cataract with unusual imprint seen in the same eye as shown in Figure 3.


Posterior polar cataracts are not to be confused with the hyaloid corpuscle ("physiologic” rest of the hyaloid artery - cataracta polaris spuria), which as previously mentioned is not located at the posterior pole but is somewhat nasally decentered from it. Like the anterior polar cataracts with which they sometimes coexist, posterior polar cataracts have varying configuration and size (Plate LXI, fig. 4). Some have dense snow-white centers with fainter irregular borders, while others resemble icicles or are porous or vacuolated, not unlike that of cataracta complicata. Their size may also vary greatly from small spots to large disks or saucer-shaped opacities. These disks may be flat, confined to one area, or form pyramids. Reduplication or imprint is common. Just below the capsule they may cause posterior protrusions like a rudimentary posterior lenticonus. As a matter of fact, the latter is frequently marked by polar cataract. Postenor polar cataracts may be complicated by the presence of other types of fetal cataract, e.g., cataracta centralis pulverulenta. Vogt reported a posterior polar cataract in a case of bilateral aniridia (aniridia was found in this family in two out of three siblings and was associated with nystagmus and absence of the macula). The polar cataract consisted of two parts, a small subcapsular portion and a second layer of opacity in the region of the pole of the posterior adult nucleus.


The ingrowth of new lens fibers may separate the opacity partly or completely so as to form an imprint or the so-called reduplication cataract. Partial separation may result in the typical "dumbbell” or "collar stud” shaped opacity, a stalklike process composed of single or multiple strands connecting both ends. The mechanism and time of formation of these opacities is still not exactly understood but many theories including experimental data have been advanced. Depending on its individual characteristics, the period of formation may vary. In certain rare instances the pyramidal shaped opacity may extend forward to be connected with the cornea and according to Mann might indicate an earlier development (at or after the eight mm. stage) , the fault l5dng in an imperfect separation of the primary lens vesicle from the surface ectoderm. However, in most cases (and with more convincing evidence) it is now believed that the development of this anomaly occurs at a later stage. Two chief factors seem to point to this. First the fact that without exception, in cases of polar cataracts the inner fetal nuclei with their Y-sutures are found to be normal. It is hardly conceivable that this part of the lens could remain normal if there was interference with or failure of perfect separation of the lens vesicle from the ectodermal surface. Added to this is the point that polar cataracts never extend to the fetal nuclei, being limited to the central parts of the cortex and adult nucleus.


Secondly the frequent finding of attached pupillary membranes to anterior polar and capsular cataracts.f This could place the development of these opacities at a later time when the pupillary membrane is formed (i.e., after the separation and completion of the primary lens vesicle, 25 to 30-mm. stage - 8 to 9 weeks). The exact role played by the pupillary membrane on the anterior capsule in the genesis of polar cataracts is not known. A suggestive possibility (Vogt) is that there is some interference with the circulation owing Vogt found a case in which an anterior polar cataract occurred in association with punctate fetal nucleus opacities. This is perhaps an accidental or coincidental association.


Both Horner and Terrien reported cases in which threads were seen attached to posterior polar cataracts. In these cases there were no injuries or signs of inflammation.


to faulty anastomosis or too early degeneration of the vessels of the central areas. However, it is also possible that disturbances in these vessels may result from fetal inflammations. The deeper displacements of the opacities and formation of imprints in polar cataracts can be best explained by the ingrowth of new fibers which in itself is physiologic.


Some writers have denied the hereditary determination of capsular and polar cataracts. However, without considering those in which the question of frank trauma or secondary disease (as indicated by corneal opacity or signs of previous iritis) it can be said that they are transmitted as dominant Mendelian characteristics. Vogt postulates that according to pedigrees only certain forms (i.e., macroscopic and microscopic, pyramidal or flat-shaped ones, with or without pupillary membranes or imprints) can be regarded genetically as being of the same order, i.e., variations of hereditary polar cataract.f In view of their usually serious damage to vision and dominant transmission these cases represent a problem for the geneticists. However, as is the case with many severe hereditary ocular defects, persons having them are less likely to propagate and hence the defect in itself acts as an eliminating factor.


Opacities in the Vicinity of the Fetal Sutures

Anterior Axial Embryonal (Fetal) Cataract (Yogt ) . This form of stationary cataract, although it had been noted previously, was not completely understood until 1918 when Vogt, employing the narrow beam, described it as an entity. Because of its axial location, it can be easily seen even with the undilated pupil by means of the optic section, narrow angle, and careful focusing of the microscope in the central area using the dark interval as a guide. It occurs in from 20 to 25 per cent of normal persons but is not necessarily bilateral. The whole figure and the component parts are so slight that it does not ordinarily interfere with normal vision. Its appearance and location is so distinctive that errors in diagnosis are hardly likely. Characterized by great delicacy, it consists of fine intensely white dots, occurring singly or in groups, invariably located within or in the immediate vicinity of the anterior Y-suture (Fig. 378; Plate LXII, figs. I, 2, 3). Only rarely are they located within the central dark interval. With age they may appear slightly yellowish in color. The design of the opacity can be formed by isolated or contiguous small groups of dots, which may be joined to one another by fainter nebulous veils. The opacities may or may not lie in one plane, usually in that of the suture, or if not some of the individual groups may be found slightly anteriorly or posteriorly, the intervening distance generally being minute. The little opaque areas are formed of the finest white dots held together by a delicate veil-like opacity some times no more marked than if they were a misty halo. Occasionally the groups situated at the ends of the arms of the Y will serve to accentuate the suture or, if more extensively developed, may outline it completely (Fig. 378) . The opacities veiled by a surrounding haziness, which outlines the ends of the suture arms, may appear rounded and may glitter like a hanging jewelled pendant supported by a delicate chain (the suture) (Fig. 378). At times* this type of cataract may only be indicated by a few isolated dots, irregularly distributed or in the form of short lines or in a circular disposition (Fig. 378) . Because of its central location, the time of its formation was thought to be in the early period of the form^ition of the primary lens vesicle. Actually it is found to be connected with the anterior Y and not with the central interval. This suture first becomes apparent at the beginning of the third month. During the third month the anterior is completed, but the lens diameter at this time is only about i mm. Since the axial embryonal cataract can occupy a region measuring from I mm. to 2.5 mm., its earliest development (according to Vogt) should be traced to the late part of the third month or early part of the fourth month. Because of its frequency, even in otherwise normal lenses, this type of opacity is commonly found accidentally associated with other types of congenital and acquired Cataract. Vogt observed that in some pedigrees the anterior axial embryonic cataract is a hereditary dominant and suggests that the frequency of this hereditary type can be explained by the fact that opacities that do not affect vision do not have an eliminating value.


As previously discussed on page loio, the lens is built up of concentric layers composed of fibers deposited one on the other in radial rows (Rabl and Vogt) . In this way the apposition of newly formed layers displace, wholly or in part, any opacity located in the anterior parts to a deeper plane This type of displacement has been observed in other forms of cataract, e g , zonular, traumatic and in the subcapsular opacities of glaucoma. The zones of discontinuity seem to have a definite relationship to the displacement and also is a preferred locale for cataractous change In some polar cataracts it may be noticed that the separation or reduplication occurs behi'cen these zones and that the densest part of the opacity IS located on them (This type of vulnerability is also typical foi the sutures ) While in others the cataract may cause a fusion of the anterior zones of discontinuity resulting in a consergence of their direction as they merge with the opacity. This probably results from the fact that the opacity (when very dense) prevents the ingrowth of new fibers in these regions, a condition which interferes with the sagittal development of the lens (tliickncss) as IS often seen in special cases and w'hich in extreme cases could result in a form of central umbilication.

t If the gene for the normal anterior pole is designated as P and that of polar cataract as p then according to Mendel’s formula of 'back crossing” PPXPp=2(Pp+ pp) In other words proiided the number of progeny is sufficient!} numerous half of them will inherit the defect In one family of ten children, four were affected, a status where p is dominant to P.


PLATE LXII


Fig. I. Form of anterior axial (embryonal) cataract.

Fig. 2. Form of anterior axial (embryonal) cataract.

Fig. 3. Form of anterior axial (embryonal) cataract.

Fig. 4. Anterior suture (stellate) opacities.

Fig. 5. Posterior suture (stellate) opacities.

Fig. 6 . Unusual type of suture (stellate) cataract. Diffuse illumination.

Fig. 7. Unusual type of suture (stellate) cataract. Direct focal illumination.



The hereditary character of this opacity was further exemplified in the study of identical twins. In two sets - eight eyes - the type of opacity was identical, differing only slightly in number and distribution. In these identical twins Vogt also noticed the similarity in the rests on the posterior surface of the lens, i.e., the arcuate line and floating hyaloid remains. In his opinion the reabsorbing processes in the region of the posterior pole of the lens (in normal eyes) are governed by heredity. This would add another "idio-variation” to those known to depend on the "normal” mechanisms of hereditary processes, e.g., curvature of the cornea, length of axis of the eyeball, pigmentation of the iris, development of the iris frill, shape of the pupillary pigment seam, shape of the disk, and course of the retinal vessels, etc.


Stellate Cataract {Anterior and Posterior) (Synonyms: Cataracta stellata, triradiate or sutural cataract.) Stellate cataract is a rather striking axial opacity invading the anterior or posterior fetal sutures, either singly or together. It delineates the suture distinctly and when marked may be observed at times even with the unaided eye. Cataracts of this type tend to have a solid appearance, their thickness and width varying from place to place irregularly, becoming especially wide at the places of branching. In some cases the edges of the suture opacit} are scalloped, giving it a festooned appearance. The blanches 01 aims of the suture cataract may measure up to 1.5 mm. in length making the total size of the figure relatively large.


Frequently each individual suture cataract may be composed of a double layer, each layer differing in width, thickness and particularly in color. In some cases these layers appear as if they were fused one on the other but in others it will be seen that one arm or another lies a little in front of the corresponding deeper one. In any case they do not form an exact replica of each other. Often, small dots or disklike opacities will be found in the vicinity of these figures. The deeper figure of each suture cataract (anterior and posterior), i.e., the one closest to or directed toward the dark interval, is more transparent and hence appears bluish or greenish in color (a phenomenon not unlike that seen in cerulean cataracts) (Plate LXV, figs. 4, 5, 6, 7). The intensity of this color display depends upon diffraction and varies with the change in angle between illumination and observation. The blue or anterior part of the posterior suture cataract corresponds in outline to the A and lies in front of it. On the other hand the deeper part of the posterior suture cataract is densely white and is usually wider and longer in extent. The location of the smaller, bluer figure anterior to it corresponds to an older segment and by the time of formation suggests a separate development (Vogt) . Not all stellate cataracts have this double formation. There are instances when the opacity is all blue or greenish, or others where it is completely white. Likewise, its consistency may vary, being mosslike or feathery, approaching that of cataracta dilacerata (page iioi) . It is not unusual for the stellate type of cataract to coexist with other forms of developmental cataract, e.g., zonular, cerulean, and dilacerata, although it may be found in an otherwise normal lens.



Fig 379. Stellate (anterior) cataract. (Resembles anterior axial embryonal cataract.)



When a stellate cataract is confined to the anterior Y-suture only and is poorly developed, it might be confused with anterior axial embryonal cataract (Fig. 379). Differentiating features are (i) the delicacy of the anterior axial embryonal cataract, which is composed of small groups of dotlike opacities, frequently surrounded or enclosed by the characteristic veil, and (2) the fact that it generally is located closer to the dark interval. The not infrequent concomitant presence of a posterior stellate cataract would put one on his guard, although it is conceivable that an anterior axial embryonal cataract might be found coincidently with a posterior stellate cataract. The genesis and time of development of the stellate (suture) cataract, which is essentially stationarj, is not known; owing to its location and size it is generall} believed to form late in fetal life, and evidently later than the anterior axial embryonal cataract. Vogt believes that deflections or branching of the ends of the arms of the suture cataract (corresponding to the normal development of the sutures in man as against the lack of branching in lower animals) represents a sign of later development of the cataract. The branching of the suture ends normally occurs at a later period in the development of the sutures.

CONGENITAL DIFFUSE NUCLEAR CATARACT (VOGT)

Vogt (1931) described what he considered to be a new picture of a hereditary condition affecting in a total way the fetal nuclei. Unlike zonular cataract, which is made up of punctate opacities and booklets, this opacity consists of a diffuse structureless haze not unlike that of the senile nuclear cataract (Fig. 3 80). 'It differs from the latter, however, in that by outlining the shape of the fetal nuclei (inner and outer) its form is more curved and also its color is different. In the past I have seen such opacities in young adults but considered them to be a presenile or early incipient nuclear cataract rather than congenital. But since all the so-called presenile and senile changes may be genetically determined, it is not surprising that this type of cataract should appear congenitally.



Fig. 380. Congenita] diffuse nuclear cataract combined with cerulean opacities.


Vogt described cases of this type of cataract in a 4 14 -year-old girl and in her mother, aged 34 years. In the girl, optic section showed a large round opaque yellow-green nucleus. Peripherally the zone of discontinuity of the cortex was markedly divergent. With the ophthalmoscope, a rounded shadow dislocated slightly upward was seen in the pupil. The vision was 3/20 in each eye. The mother had a similar finding, except for a pointing of the nucleus in the region of the equator, a normal finding in the adult. According to Vogt this may be an effect of zonular tension. Also corresponding to her age, the cortical thickness was greater in the mother, and because of shrinkage, the nucleus was smaller. There was a fainter layer of more grayish or bluish relucenc}'^ in the peripheral cortex. In both there were anterior axial embryonal opacities. With the ophthalmoscope the central shadows in the mother were somewhat denser than that in the child. Vogt found similar opacities in the mother's sister and brother and consequently considered it as a dominant hereditary disease of the lens nucleus.


CONGENITAL, EMBRYONAL OR FETAL NUCLEAR CATARACT (CATARACTA CENTRALIS PULVERULENTA AND DISCIFORM CATARACt)

This form of congenital nonprogressive cataract which is composed of small punctate dots of varying sizes arranged in the shape


Fig. 381. A. Cataracta pulverulenta (congenital fetal nuclear cataract). Diffuse illumination. B. View of above by means of the optic section. Direct focal illumination.


of a disk, lies in the central part of the lens, i.e., in the fetal nucleus. It has been suggested that it is a forme-fruste of the larger zonular cataract, especially since alternating occurrence of the two types have been seen in the same family. It is practically always bilateral but is rarely of sufficient density to greatly interfere with vision. Apparently this type of central cataract was inaccurately localized by many writers in the posterior parts of the lens before the days of biomicroscopy although they realized its hereditary (ideokinetic) and nonprogressive nature. Nettleship and Ogilvie f (1^06) published an extensive report on this type of cataract, occurring in the descendants of a certain John Coppock born in 1774 in Oxfordshire, England. Earlier, Doyne reported several cases in this same family.

Also possibly hereditary forms of tire smaller central zonular (lamellar) cataract; disciform or Cippock cataract (Nettleship and Oliver), Doyne's discoid cataract, family nuclear cataract.

■f Nettleship, E., and Ogilvie, M. F. A Peculiar Form of Hereditary Congenital Cataract,” Tr. Opbth. Soc. U. Kingdom 26:191 (1906).


PLATE LXIII


Fig. I. Central discoid fetal cataract. Right eye. By diffuse illumination.

Fig. 2. Central discoid fetal cataract. Same as Figure i. By direct focal illumination. Unusual form.

Fig. 3. Partial form of the central discoid fetal cataract. Left eye. By diffuse Illumination.

Fig. 4. Same as Figure 3. Direct focal illumination.

Fig. 5. Cataracta centralis pulverulenta associated with anterior lamella opacities. Diffuse illumination.

Fig. 6. Same as Figure 5. Direct focal illumination.

Fig. 7. Central discoid similar to case in Figure i.

Fig. 8. Congenital central punctate opacities. Similar to case shown in Figure 5.


Other cases, not related to the Coppock family, were mentioned by Parsons and Harman. Vogt,'"' in 1921, unaware of the English reports, described a similar form as a new variety of congenital cataract, which he termed cataracta centralis pulverulenta. Later, Gifford f (1927) pointed out that cataracta centralis pulverulenta was probably identical with Coppock and Doyne’s cataract.


Ordinarily, it is shaped like an elipse and is made up of fine points (Plate LXIII, fig. (3) . These points vary slightly in size and are usually most condensed in the central part of the opacity where they may obscure the Y sutures. In others a concentric ring form may be seen in which the central part is composed of more irregular, larger spots, making them whiter in appearance. This is surrounded by one or more rings of finer dots. Vogt has illustrated several variations of this lesion; among them is a case in which white points were found in front of the central interval, or the place where the anterior axial embryonal cataract is localized. There were no opacities in or behind the dark interval. Some of the spots were surrounded by a small halo. In the periphery of the area occupied by them they were arranged in lines forming a figure suggestive of an irregular star. In another case, there was a lens-shaped opacity, the equatorial diameter of which measured 0.5 mm., located with the narrow beam a little in front of the center of the dark interval, filling the anterior region of the dark interval and that of the anterior Y-suture, which could not be seen. The posterior A behind was visible and uninvolved. In the periphery the dots, in contrast to the above-described case, were not linear but gradually faded into the surrounding unaffected areas. There were no concentric layers but the equator of the opacity was rounded or circular. By strong magnification the dots appeared as brilliant white platelets of varying size. The largest were 0.05 mm. and the smallest were like dust. The thickness of the entire opacity was estimated at about a little more than half the equatorial diameter. In the zone of discontinuity corresponding to the adult nucleus a second but less conspicuous zone of opacity was seen. About

- Vogt, A., Hand, der Spaltlat/ipe Mkroscopie, 1921.

t Gifford, S., "Zum Kongenitalen Star des Embyronalkerns,” Klin. Monatsbl. f. Augenh. 28; 191 (1927).


1 5 hooklike opacities or riders were distributed on the circumference of the nucleus. Bellows also reported such a finding in a 3 6-yearold man with normal vision, in whom a central area, measuring 2.5 mm. was surrounded by an outer ring of hooklike radial opacities measuring 4.5 mm. in diameter. Because of this not too infrequent combination, i.e., cataracta centralis pulverulenta and booklets of the adult nuclear zone, it is possible that this type of cataract may represent a transitional or earlier (hereditary) form of zonular cataract. In a third form he noted a ring of fine dots forming a concentric layer around the anterior Y-suture behind which was a small dehcate opacity (disklike) that glistened somewhat and measured about i mm. in vertical diameter. The outer ring measured 2.7 mm. These variations are all similar to the typical opacity of cataracta centralis pulverulenta in that they involve the central interval, they measure no more than i to 3 mm. in diameter, and they are all composed of fine dots and dustlike opacities, which are not dense enough to interfere with normal visual acuity. I recently have observed an unusual type in which the anterior Y itself was heavily infiltrated not unlike the stellate cataract. Vogt reasoned that since the lens vesicle has an equatorial diameter of about 0.5 mm. in the third month and from 0.9 to 1.4 mm. in the fourth month, the opaque part of the lens ordinarily would correspond to the size of the latter at the third month. This corresponds to the time of beginning development of the pupillary membrane and of a consequent change in the manner of the lens nutrition. An interference with lens nourishment might conceivably result in this type of cataract.


Vogt found forms of cataracta centralis pulverulenta three times in two generations, indicating a dominant transmission. In Russo’s cases two brothers were affected. Following a consanguinous marriage of one of the brothers, the three sons had these cataracts. The children of the nonconsanguinous marriage of the second brother were free of this defect. According to this, the pulverulent opacities in these cases would be of a recessive type. However, A. Rados (Archives of Ophthalmology, July 1947^ Vol. 3 P, pp. 57 - 77 ) in an excellent study of central pulverulent cataract and its hereditary transmission, questions the validity of Russo’s assertion that in his family there was an apparently Mendelian recessive inheritance. From a detailed study of pedigrees Rados showed fairly conclusively that "In the hereditary form of central pulverulent cataract, the dominant mode of inheritance is to be expected in accordance with the knowledge of inheritance of various forms of hereditary cataract.”


On several occasions I have seen another discoid type located in the same area of lens which instead of being composed of dots was characterized by more solid and opaque lamellar-like leaves (Plate LXIII, figs. I, 2, 3) surrounding the fetal nucleus. The disk may be complete or only partially formed (Plate LXIII) .

ZONULAR (lamellar) CATARACT

The zonular, or lamellar, cataract in its common form appears as a central discoid opacity. Ordinarily it occupies the outer fetal nucleus or areas just outside it and consists of fine white points and peripheral riders. One might compare it to the kernel of a nut, the outer shell representing the adult nuclear stripe. There are many exceptions both in regard to composition and location. These will be dealt with later. As compared to other forms of cataract in the young, its frequency is high. In the past some writers went so far as to state that it is the most common type of lens opacity in youth. This is understandable since in most cases zonular opacities are comparatively large; they occupy a greater portion of the central area of the lens and, consequently, affect vision seriously. In addition they are easily recognizable (Fig. 382). With the dilated pupil, they can be diagnosed macroscopically. But since the advent of biomicroscopy, the focal beam has revealed a higher incidence of the more delicate congenital opacities, such as anterior axial embryonal cataracts and cataracta centralis pulverulenta. These do not affect vision and unless they are unusually dense, they cannot be seen with the ophthalmoscope or by diffuse illumination.

Zonular cataracts may be congenital or acquired. They are generally bilateral; only about 5 per cent of cases are uniocular. They may arise pre- or postnatally. The congenital ones are either hereditary or are caused by exogenous influences which may correspond to those known to cause zonular cataract after birth (e.g., hypocalcemia [tetany cataract]). Congenital zonular cataracts may also be found secondary to fetal inflammation or in association with other malformations, e.g., microphthalmos, pupillary rests, iris colobomas, etc. Probably, a considerable number of the zonular cataracts arising prenatally in the first few years of life are associated with infantile tetany (see chapter on endocrine cataracts). A similar relationship has also been found in cases of zonular cataract occurring in older individuals (Meesmann) . Apparently they may arise in cases of spontaneous latent tetany as well as in those following inadvertent damage or removal of the parathyroids in operative procedures on the thyroid (see endocrine cataracts, page 1185). In addition, especially in the young, a type of zonular cataract may develop after trauma (page 1257).



Fig. 382. Zonular cataract.


The optic section permits localization of the involved areas and visualization of the internal structure (inner fetal nucleus and dark interval may or may not be involved - Fig. 3^3)5 many of the variable details found in this type of opacity may also be recognized. As already mentioned the common variety is localized principally in the outer fetal nuclei and the deeper layers of the so-called “adult nucleus” and is usually composed of fine white dots, although at times larger flattened spots may be seen. A thin veil-like envelope may surround the main central opacity. In front view, this envelope may be represented by one or two thin concentric lines separated from the central opaque disk by a narrow clear area (Plate LXIV). At times the envelope is thicker and may be made up of fine white points. Extending at right angles to the envelope and often contained in it are the characteristic “booklets” or riders. In only rare cases are they absent. Sometimes larger riders extending some distance from the equator alternate with smaller ones that are closer to it. Isolated ones are found around the equator of the opacity but are also separated from it. The location of the riders frequently corresponds to that of the suture system but may in addition be situated in between them. These riders often have pointed ends and are very white in color. They may be formed from individual fibers or bundles of fibers that have become isolated from the main opacity. Vogt has described several different pictures. He has reported that


  • Perhaps even these are genetically determined only in the indirect sense that they follow a hereditary defect in other organs (hormonal) which in turn could result in toxins or interference with lens metabolism.



Fig. 383. Zonular cataract.


PLATE LXIV


Fig. I. Zonular cataract. Illustrating central punctate opacities. Surrounded by a delicate envelope and booklets. Diffuse illumination.

Fig. 2. Same as Figure i. Direct focal illumination. Optic section.

Fig. 3. Zonular cataract. More solid type.

Fig. 4. Variety of lamella (zonular cataract). Right eye. Diffuse illumination. Fig. 5. Optic section of case in Figure 4.

Fig. 6. Left eye of case shown in Figure 4. Diffuse illumination.

Fig. 7. Linear type (incomplete) of zonular cataract. Diffuse illumination. (Courtesy of Dr. Webster.)

Fig. 8. Direct focal (optic section) view of case shown in Figure 7.


the sagittal thickness of lenses having zonular cataracts is less than normal, indicating lag in development in lenses having this type of cataract. In some cases radial slits or clefts are seen in the peripheral parts of the opacity, some of which extend to the equator of the opacity where they appear like wedge-shaped defects. The sutures themselves may not be visible. The bases of the wedge are directed toward the periphery (the equator) , A radially directed rider may occur in the clear part of the wedge-shaped crevice, its curved part extending out from the crevices in the region of the envelope. At times these crevices may be closer to the axial parts of the lens, but even these will be found to contain a linear streaklike opacity (rider) whose direction corresponds to that of the wedge. In one case of this kind polar cataracts occurred which connected the capsule to the central part of the opaque nucleus. In another case a dense central zone, made up of dots, was surrounded by one of lesser density occupying the adult nuclear zone (envelope), composed of concentric and radiating opaque lines and larger flat opacities. Within the inner disk was an irregular layer of crystals. The inner disk measured j.a mm. and the total diameter of the outer one was 8 mm. The great size of such a lens opacity would indicate postnatal development, since it is much larger than the normal fetal nucleus. In some in stances zonular cataracts are marked by the presence of a welldeveloped suture system. This form distinguishes itself by a sharp equatorial margin (without an envelope) , by punctate opacities with a clear center (inner fetal nucleus), and by densely opaque white suture lines at the surface of the opacity. This is the "suture” type (suturata) to be distinguished from the aforementioned "cleft" type.



Fig. 384. Oitaracta pulverulenta with stellate or suture cataract of the anterior Y suture.

Note its small size as compared to zonular cataract.



The inner fetal nucleus may also be involved, presenting a central punctate opacity within the outer one. They may or may not be separated from one another by a clear interval. The central dark interval (embryonal nucleus) may be free of opacities, leaving a dark slitlike area between the affected coffee bean-like nuclei. In other instances, the dark interval contains punctate opacities, and the inner fetal nucleus is clear. When this is the case, there will be a greater distance (dark) between it and the outer affected nuclei. Another interesting variety is that in which the surface shows neither sutures nor punctate opacities but is made up of an irregular concealing layer of opacities containing radiating lanceolate lens fiber clefts. Vogt states that this type resembles the subcapsular layer forms seen in tetany cataract.


The combination of zonular cataract and presenile (coronaria) and senile cataract is not unexpected. The combination of polar cataract and zonular cataract seems to justify the opinion that certain zonular opacities are hereditary. Vogt writes that he has seen a case of total cataract in early youth develop into a zonular opacity through the apposition of new fibers. In addition to the well-developed zonular cataracts, there are certain forms of opacities which, because of their location (outer fetal nucleus) and lamellar character, are to be considered as abortive (formes fruste) - or at least related to - zonular cataracts (e.g., congenital nuclear cataract) . These may be seen as small, localized layer opacities only partially outlining the outer fetal nucleus (Plate LXIV). Some are axially located and others, outline the equator of the fetal nucleus. An especially interesting case of this type in an exaggerated form was recently called to my attention. It occurred in a 34-year-old man whose sister had tetany cataract (referred to on page ii86). In both of his eyes there were flattened leaflike opacities located just outside the fetal nucleus. The flattened leaflike structure extended around the equatorial border of the nucleus (similar to zonular cataract), the anterior ends curling like the petals of a flower in the process of opening. The opacity itself was white, shiny, and lardaceous, showing no punctate structures.


OTHER RARER FORMS OF CONGENITAL AXIAL CATARACTS

Certain of the rarer axial congenital cataracts were described before the discovery of tlie biomicroscope (e.g., coralliform, and axial fusiform cataracts) , while others like the spear cataract, cataracta pisciformis, and the floriform cataract were described and named afterward. In prebiomicroscopic days there was no possibility of exact localization, as we now understand it. The suture system and zones of discontinuity (as seen in optic section) and their significance as regards the normal embryological and postnatal development of the lens were unknown. Consequently, using more or less diffuse illumination or transillumination (ophthalmoscopically) only surface or frontal views of lens changes were obtained. This naturally resulted in a morphologic classification based on frontal appearance alone. With the advent of the biomicroscope, two added features in diagnosis became possible: (i) the ability to see through opacities and other changes sagittally and ( 2 ) exact localization of the lesions or, better, correlation of their position with the zones of discontinuity or growth rings of the lens. Today we are better able to approximate the time of formation of defects in relation to the ontogeny of the lens. There is still much confusion in the literature concerning these rare forms of congenital axial cataract as is seen by the overlapping descriptions and by the different names that have been given to apparent variations of the same forms. These opacities may or may not be confined to any single zone or zones of discontinuity. Some are localized in the outer fetal nucleus or in the adult nucleus; some extend outward from the fetal nucleus and pass into the adult nucleus or even into the cortex to the neighborhood of the capsule (coralliform, fusiform, and pisciformis, etc.). Although these opacities differ one from the other in structure, extent and location they have two important common characteristics: (i) they are of a hereditary nature and (2) they are predominantly axially located. Like so many developmental congenital cataracts, no adequate explanation for the mechanism of formation of these types of axial cataracts has been found, especially for those which do not follow the orderly arrangements of the lens structure. Following Knies (1877) and later Hess (1893) and Collins (1908),^^® Mann suggested that abnormal adhesion of the embryonic nucleus (primary lens fibers) occurs to the capsule at the anterior pole or to the posterior pole, or (as in the case of fusiform axial cataract) to both. Hence, as the lens continues to develop these centrally attached fibers will stretch, become opaque, and prevent the secondary fibers (growing from the equator) from separating the capsule at this point. This they must do in order to meet and to form a normal suture. Failure of separation of the primary fibers from the anterior capsule might result in a coralliform cataract, while failure of separation from both anterior and posterior capsule would lead to an axial fusiform cataract. One might further h)pothecate that some of the other rarer forms of axial cataract (spear cataract) might result from modifications of this type of defect, depending on the time of growth of the epithelial cells genetically affected. It is difficult to explain the pathogenesis of che opacities situated outside of the fetal nucleus in an otherwise normal lens except by virtue of their proximity to the capsule in fetal life.


The rarer forms of congenital axial cataracts to be discussed in this section are:

1. Cataracta pisciformis and associated types (Vogt)

2. Coralliform cataract

The observations of Hess (1893) confirm this idea. He described a chick embryo in which there was a failure in separation of the lens vesicle from the surface ectoderm as a result of which the primary lens fibers grew through an opening in the cornea. Had this closed and had growth been resumed, one might surmise that an axial cataract would have formed.


3. Axial fusiform cataract

4. Spear cataract

5. Floriform cataract

Cataracta Visciformh. Under the caption "hereditary fish- to finlike juvenile band cataract” (cataracta pisciformis) Vogt described several types of predominantly axial cataracts (Plate LXV figs. 1-6). First, the pisciformis, which are axially located, thin, white spotted opacities limited to either the posterior adult nuclear zone or in the juvenile form to the region of the posterior outer fetal nucleus. The ends of the opacity are somewhat curved, giving them the shape of a fin (Vogt). In one case they were associated with a few irregular dots on the adult nucleus and in the cortex anteriorly and posteriorly.

Second, a rare ring of hooklike or zigzag opacities localized to the periphery of the anterior outer embryonal (fetal) nucleus plane. These were found bilaterally in one patient, a young man of 28 years. The zigzag line of opacity was only seen frontally. In section the opacity did not involve the equatorial curvature of the nucleus (as do the hooks in zonular cataracts) but lay like a line on one plane.

Third, ringlike flattened opacities, having a dark central hole (Rosskiimmelahnliche) and arranged in radial groups. They are found grouped in the axial region of the adult nucleus and extend peripherally in a radial direction diminishing in size; this radial formation suggests a relationship to the suture system. As Vogt has intimated the appearance of both cataracta pisciformis and Koby’s later described floriform cataract are similar.

Fourth, spotted cataracts (white or blue) of the anterior and posterior outer embryonal (fetal) nuclear zone. These are groups of axially located small flat spots whose color varies from white to blue, depending on their thickness. Some are irregularly distributed while others assume a radiating form. In a few of these cases there were peripheral cerulean opacities.

Fifth, a blue-green anterior rosette cataract with a layer of white spotted opacities in the anterior and posterior fetal nucleus. In the deep part of the adult nucleus there was a bright blue-green rosette composed of dense longish and round radially arranged spots which merged into one layer. The anterior Y-suture stood out densely white. In addition there was a white spotted layer of opacity in the anterior and posterior fetal nucleus. The posterior one was more prominent.


PLATE LXV


Fig. I. Cataracta pisciformis (floriformis) . Right eye. Diffuse illumination. Fig. 2. Left eye of case shown in Figure i. Note anterior suture cataract. Diffuse illumination.

Fig. 3. Ffigh-power view of the opacities seen in Figure 2. Diffuse illumination. Fig. 4. Direct focal illumination of the anterior part of case as shown in Figure i.

Fig. 5. The opacities in the deeper (posterior part) of case shown in Figure 2. Diffuse illumination.

Fig. 6. Same as case in Figure 5. Direct focal illumination.

Fig. 7. Unusual form of cataracta pisciformis (floriformis). Diffuse illumination.



Sixth, a rosette-like branched opacity at the posterior adult nucleus with a central zone of round button-shaped opacities (nodiformis) ; myopia and coloboma of the macula. Chiefly on the posterior surface of the adult nucleus in the axial region there was a cloudy vacuolar opacity with whitish bands radiating to the periphery. Partly in the center, partly on the radiating strands of opacities there were about a dozen white condensations resembling buttons. Some were found on the posterior capsule. V ogt also found similar structures in spear cataract. These seem to resemble spheroliths.

CoraUiforvi Cataract, Except for the cases reported by Riad and Gifford and Puntenney,"*^® most of the cases of this form of hereditary axial cataract in the past were described without benefit of the biomicroscope. According to the original description by Gunn^^® in 1895 in a young man, 22 years of age, it was characterized by rounded or elongated opacities, the ends of which were often ampulliform. There were small crystals seen in the unaffected parts. Nettleship described similar cases and established its hereditary nature. According to him, coralliform cataracts were made up of gray or white opacities arising from the deeper axial region and coming forward often to reach the anterior capsule. He said that each branching process expands into a trumpet-shaped opening like the "mouth of a coral” (Fig. 385). Knies (1877)^®® compared the anterior projection to the vanes of a windmill. In 1906 Stephenson wrote of a case (a 30-year-old man) who had an optical iridectomy. The coralliform cataract consisted of "little pipes” in an opaque mass; some of them originated from the equator and others from the anterior surface, "the whole similar to a piece of coral.” H. Fisher believed that this case represented a special form of zonular cataract.


In some instances (Riad) the opacities were elongated and resembled radiating tubes with open circular ends anteriorly. Except for some glistening crystals in the neighboring clear parts, the lens


Fig. 385. Coralliform cataract.


showed no other opacities. In a case described by Gifford and Puntenney, the axial opacity was irregularly stellate or floriform and extended to the anterior capsule frontally, connected to it and facing posteriorly was a larger replica of the anterior one. In other words, in this unusual form the opacity extended through all the layers of the axial region. In these reproductions the main central lesion was surrounded by numerous white dotlike spots. These authors also reported a rare form of crystalline cataract in which the crystals were found in a compact circular mass involving successive layers of the cortex. Vogt in his discussion of spear cataract (see below) raises the point whether the so-called coralliform cataracts are related to them.

According to Gunn's picture and description this relationship is not certain. Fisher also described a coralliform cataract in which the opacity in the cortex resembled iridescent coral. An axial spindle connected the anterior and posterior cortical opacities.


Axial Fusiform Cataract. In this extremely rare anomaly the opacity extends axially through the lens thickness (Fig. 3^^)' Fless cites two cases reported by Knies (in brothers, in one of whom it


was bilateral) in which apparent anterior and posterior polar cataracts were connected by a thin opacity. A possible explanation of its pathogenesis was offered by Knies and Collins (see page 1080)

Spear Cataract. This is a peculiar form of hereditary cataract, characterized by the presence of an opaque mass located in the central portions of the lens; it consists of needle-like or vermiform structures. The direction and course of these formations do not follow the normal architectural structure of the lens. The needles were frequently arranged in long bundles, a grouping often seen with tyrosine crystals. In other cases they diverged in various directions rarely crossing one another (Fig. 387). This structure, according to Vogt, differs from that of the rhomboid cholesterin crystals, which he saw in total traumatic cataract; in the latter the needles were grouped to form plates. In spear cataract it was his impression that the needles might be a product of crystallization within a shapeless mass. Flis first cases (1921-1922) were found in both eyes of a 9 "â– I could find no other cases reported in the literature.

t Speisskatarakt (Vogt) .


year-old boy whose vision was 6/24, and his mother aged 32 years. In the case of the mother there were several round button-like opacities 0.02 to 0.08 in diameter (spheroliths ?) in the central parts


Fig. 387. Spear cataract.


just in front of the posterior capsule in the right eye. The needles had spokelike projections, some of which glittered with a color display. The length of the spears varied from 0.5 to 2 mm. in length. Later examination of 42 relatives of this family revealed 10 cases of spear cataract. In some of these the opacities resembled a spinous cactus plant in that central processes had branching and crystallike brilliant spears whose extent and direction disregarded the anatomic structure of the lens. An axial cataract was described by Gifford (1924)^^^ in which there were fine branching needles arranged in a manner that reminded him of two fir trees, base to base in the center with their apices approaching the anterior and posterior capsule. This could have been a form of Vogt's spear cataract.

Floriform Cataract. According to Koby, this type of rare congenital cataract, predominantly axial, seems to be an intermediate form lying between cataracta stellata and coronary cataract. Gaellemaerts, who also described a case of this kind, confirmed this conception. Other cases were reported by Veterbi and Meesmann. Koby stated, "the cataract is composed of a certain number of opacities, 30 to 100. Each opacity is itself formed of elements of a round annular form. By grouping several elements, 2 to 20, there arises a series of cerulean opacities, arranged like a flower, the apparent size of which varies from 0.5 to 0.75 mm. on an average.


Fig. 388. Oitaracta floriformis. (After Koby.)


The opacities are flattened occasionally like a mulberry, but sagittally have no connection among themselves. The cloudiness is more dense at the periphery than at the center and the opacities, examined by transillumination, appear diaphanous. Their color is whitish or bluish in oblique light, yellowish in reflected light. They are sometimes lustrous” (Fig. 388). These opacities are found axially in the close vicinity of the fetal Y-sutures and at times take this shape. Because of the fact that he found this cataract in one family (mother and four children, three of whom showed camptodactylia), Koby considers that the anomaly seems to behave as a dominant mendelian character. Vogt has intimated that Koby’s floriform cataract resembles the ring form of cataracta pisciformis.

RARE FORMS OF CONGENITAL CATARACT AFFECTING A GREATER PORTION OF THE LENS

The cataracts referred to in this category are the diskshaped or ring form cataract and the congenital morgagnian cataract. These are rare forms of total cataract and as such have been of less interest to biomicroscopists. As a matter of fact, of the half dozen or so reports on total cataract only in one or two recent cases have they been examined with the biomicroscope.


Disk-shaped or Ring-form Cataract. This form of total cataract is rare as a congenital manifestation. A similar or corresponding form is more frequently seen as a secondary cataract following discission of congenital cataracts, extracapsular operations, shrunken lens and after perforating injuries (Soemmerring’s ring) . According to the descriptions in the literature, the congenital form appears as a thin, dense whitish opacity filling the pupil. The central part may be calcareous. In several cases it was associated with corneal opacities (leukoma adherens and staphyloma) and in one with a persistent pupillary membrane. Histologically^' the center of the disk is very thin and scar-like while the periphery is clubbed and composed of degenerated lens fibers, the whole formation reminding one of a umbilicated red blood cell. Ida Mann states: "The most apt embryological explanation is that the nucleus has failed to develop, has shrunk and calcified and remained adherent to the capsule so that the outer fibers could not grow around it but merely plaster themselves to the equatorial region.” The reason for the failure of development of the lens nucleus is not known but it has been hazarded that the cause may lie in the failure of the epithelium lining the posterior wall of the primary vesicle to elongate to form fibers.


Congenital Morgagnian Cataract. This type of cataract is rare and is of doubtful origin. No biomicroscopic descriptions of it are available. Apparently the fault lies either in a failure of development or in a secondary degeneration of the outermost zones, since the central nucleus remains more or less intact. As a result, similar to the hypermature senile morgagnian cataract, the nucleus lies freely suspended in a fluid-like substance contained within the baglike capsule. Based on the histologic examination of such a case by Hess, Mann states: “There is not a primary failure of the outer zones but a secondary degeneration. This is shown by the fact that the lens capsule is of normal size and is filled with a milky semitransparent fluid in which the fetal nucleus floats. The outer lens fibers must have been present at some time and consequently have deliquesced.”



Cite this page: Hill, M.A. (2024, March 19) Embryology Book - Biomicroscopy of the eye 2-24. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_Biomicroscopy_of_the_eye_2-24

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