Book - Biomicroscopy of the eye 2-26
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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.
|24 Developmental Lens Changes.
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26 Complicated Cataract
In its broadest sense, complicated cataract (Cataracta Compiicata) refers to lens changes incident to the action of certain toxins. These toxins may originate within the eye itself (endogenous) or may be derived from extra-ocular (exogenous) sources. The exact mechanism by which they act is not known but it is conjectured that they diffuse into the lens from the surrounding fluids and cause alteration in its metabolism. Hence they differ from developmental cataracts (congenital, presenile and senile) which in a sense are predestined either by hereditary influences or are expressions of abiotrophy or senility (the appearance of which may also be genetically determined even in isolated tissues or organs).
Although the characteristic picture of this condition is predominantly found in the region of the posterior capsule, anterior subcapsular changes occur as an expression of complicated cataract more frequently than has hitherto been considered. The appearance of cataracta complicata may vary depending on the location of the causal factor. For instance, in certain forms of exogenous complicated cataract (e.g., tetany, myotonia, diabetes, radiational cataracts), we find subcapsular layers of opacities (anteriorly and posteriorly) which may spread out over the entire lens surface. The anterior changes consist of capsular thickenings and opacities while subcapsularly thin layers of vacuoles are seen. These may be flat bands of rosette-like opacities, isolated spots and layered roundish or punctate changes. Although one might like to think that anterior complicated cataracts uniformly are associated with conditions in the anterior segment of the eye, and that posterior complicated cataract strictly follows disease within the posterior segment, actually this is not so. Cases having posterior complicated cataract sooner or later show anterior subcapsular changes. Especially common is the development of nuclear cataract. In this connection it should be pointed out that in high grade myopia and retinal separation a nuclear cataract indistinguishable from the ordinary senile variety, may be the only visible cataractous change present.
One of the great advances afforded by biomicroscopy of the lens is the ability to differentiate between ordinary senile cataracts and cataracta complicata. This is a consequence not only of their morphologic differences but also because we are better able to see changes (Inflammation) in the neighboring tissues, which may be the basis of cataracta complicata.
To the original conception of Becker (1876)- i.e., that complicated cataract follows such diseases as retinal detachment, intra-ocular tumors, cysticercus, absolute glaucoma, cyclitis, iridocyclitis, and the unknown processes, which result in buphthalmos - Fuchs (1910)^^^ added high-grade myopia and violent suppurative diseases of the cornea (ulcus serpens) . In addition, now, are included the exogenous endocrine cataracts (diabetes and tetany, myotonia, mongolian idiocy, and the dermatoses, etc.), radiational cataracts, and cataracts following intoxications (drugs, such as naphthalene, dinitrophenol, paradichlorbenzene, thallium, ergot, etc.) and also certain retained metallic foreign bodies (iron and copper) producing siderosis or chalcosis lentis. However, since many of the last-mentioned varieties have special characteristics, they will be treated under special sections. Although from the standpoint of etiology, all these forms fall under the heading of complicated cataract and seem to have a predisposition for the subcapsular regions, anteriorly as well as posteriorly, those which are secondary to intra-ocular disease (endogenous) start chiefly axially, in the posterior cortex and usually show color display and a porous consistency.
Various suggestions have been offered to explain the reason why complicated cataract, especially following intra-ocular disease, occurs predominantly in the posterior subcapsular regions. Among these is the fact that the thinnest part of the whole lens capsule is the axial portion posteriorly. In addition the absence of protective epithelium posteriorly should be kept in mind. Both these factors might conceivably offer a weaker barrier to the entrance of toxins in this part of the lens. Also to be considered is the point that the posterior portion of the lens lies in closer proximity to the sites from which noxa emanate. However, in my opinion the difference in the chemistry and physiology between the aqueous and the vitreous in this regard should be stressed. On the one hand there is a watery solution, capable of being more or less continuously renewed. On the other hand, there is the torpid vitreous gel. This significance is exemplified in the thoroughness and speed with which the aqueous cleanses itself of toxins and exudates as compared to the vitreous. The suggestion of Vogt that the sutures are places of less resistance and consequently arc sites of predilection as proved b) the frequent rosette-like formations seems to me to be well taken since most complicated cataracts assume a radiating design. The close relationship between retinal pathology and the integrity of the lens has been noted by numerous writers. The frequency of posterior complicated cataract in retinitis pigmentosa, high-grade myopia with chorioretinitic changes, as well as retinal separation bespeaks this relationship.
Biomicroscopic Appearance of Cataracta Complicata
Aiiterwr Forv?. This occurs not uncommonly as a consequence of iridocyclitis. The lens opacity is usually to be found subcapsularly, axially or paracentrally, in which case it tends to lie in the vicinity of iritic adhesions or in the region of maximum iritic involvement (Plate LXXI) . The cataract itself may be localized to one area or may be spread out in the form of thin flat bands to assume a rosettelike figure. In the early stages (cataracta complicata incipiens) the opacity, which can be missed by ophthalmoscopic examination, appears in direct focal light as a faintly grayish haze.
By diffuse or retro-illumination and higher powers of magnification the opacity is seen to be composed of delicate drops or vacuoles (Fig. 413)- In other instances it is composed of whitish or grayish points (Fig. 416 B). At times the opacity may be circular (ring form) with or without delicate radiating branches. Apparently depending on the length of time of action of the influences, these opacities may be stationary for long periods of time or may progress."* With progression they become more prominent and tend to expand in the direction of the sutures and at the same time to extend themselves deeper within the cortex. Eventually the whole cortex may be involved so that it becomes entirely opaque, made up of a vascuolar and milky substance. With hypermaturity, similar to senile cataract, capsular folds and calcareous degeneration occur and finally the entire lens may shrink into a small irregular yellow mass.
Spemann Lewis Stockard and a host of other workers in the field of experimental embryology have shown in lower animals, the dependence of the development of the lens on that of the optic cup. It is conceivable that in mammals, if there was a weakness of genetic origin in the ectodermal epithelium of the optic cup, it might also affect the lens.
Fig. I. Anterior complicated cataract following contusion. Capsular folds. Diffuse illumination.
Fig. 2. Same as case shown in Figure i. Direct focal illumination. Optic section. Fig. 3. Posterior complicated cataract (endogenous). Following iridocyclitis. Diffuse illumination.
Fig. 4. Same as shown in Figure 3. Direct focal illumination.
Fig. 5. Complicated cataract (nonprogressive) several years following a perforating injury. Located at the lens equator.
Fig. 6 . Unusual form (lamella) of anterior and posterior complicated cataract located at the level of the adult nucleii.
Fig, 413. Frontal view by diffuse illumination. Anterior complicated cataract, vacuoles and opacities. Posterior involvement not seen.
Posterior Form. As mentioned before, the characteristic posterior cataracta complicata may follow iridocyclitis as well as degenerations
In one case of healed iridocyclitis Vogt thought that after 9 years three ring-shaped subcapsular opacities with fine radiating stripes were unchanged. In another healed case, ii years later, the opacity had not progressed but was more distinct and was located somewhat deeper in the cortex. Apparently like other localized cortical opacities, it was dislocated backward by the ingrowth of new fibers.
Fig. 414. Anterior and posterior complicated cataract seen in optic section.
Fig 415. Early cataracta complicata (u\eitis). In the region of the bright specular reflex (above) a definite color display (iridescence) was noted. A few pigment deposits were seen on the posterior lens capsule.
(retinitis pigmentosa and retinal detachment) and inflammations of the posterior segment. Any and all types of conditions may occur, e.g., tumors seem to predispose to this form of cataract but not in
Fig. 416. A. Early stage of posterior complicated cataract (uveitis). Optic section. B. Note rounded form of opacities (frontal view), c. Cataracta complicata (posterior) associated with retinitis pigmentosa.
every case since nuclear cataract and posterior saucer opacities are also found with these conditions.
Typically complicated cataract begins as a localized hazy opacity adjacent to the posterior capsule and usually in the polar region (Fig. 415; Plate LXXI) . It may, however, start paraxially or even peripherally. It should be pointed out that although in most cases the cloudy opacification at its inception seems to be connected with the posterior capsule or just in front of it, rarely it may lie separated from the capsule in the posterior cortex (Fig. 417 A; Plate LXXI, fig. 6).
Fig. 417. A. Complicated cataract associated with retinitis pigmentosa located in the anterior part of the posterior cortex, b. Posterior complicated cataract associated with retinitis pigmentosa as observed in optic section.
With higher powers it will be seen that the opacity is composed of coarse granular particles within a hazy media. These particles (probably brought about by the formation of vacuoles) have been described as porQus in character (like pumice or tuff-stone) and by others as resembling bread crumbs or chopped meat. Frequently, larger ringlike opacities have a dark, more or less optically â€œemptyâ€ content (Fig. 416). This can be demonstrated by optic section. These structures represent fluid spaces surrounded by opaque borders and are also often seen in anterior complicated cataract. Unlike water slits or laminary separation they do not follow the direction of any of the lens structures (sutures or fibers) . As a matter of fact this apparent â€œlawlessnessâ€ is also characteristic of expansion of the opacification in all types of cataracta complicata. In cases of retinitis pigmentosa, a typical form of very slowly progressive complicated cataract is found (Fig. 417 A, B; Plate LXXVI, fig. 6) . It frequently is irregularly roundish or has a starlike shape with three or four radiating processes and is composed of crumblike particles or of a small ringlike vacuolar net, the centers of which are less opaque (Figs. 416 B, C) . Complicated cataract of a similar morphology is also found in the higher grades of myopia (myopia degenerativa) , especially in the presence of vitreous and chorioretinal changes (Fig. 418 A, B) . This type of change in degenerative myopia should be differentiated from posterior saucer-like opacities, which are often found in myopes of advanced age and which probably represent a senile change independent of the myopia. The same possibly holds true for the frequent finding of nuclear cataract in older myopes.
Pig. 418. Complicated cataract, a. Diffuse view. b. Direct focal illumination.
An early finding in cataracta complicata is the presence of a brilliant color display (red, yellow, green, and blue) in the affected area, especially as the zones of specular reflection are approached (Plate LXXn, fig. 6 ) . Our attention to this polychromatic display was called first by Vogt who placed much importance on it as a diagnostic feature of catar.acta complicata.'^ This color display or iridescence occurs not only in axially located opacities but also in peripheral ones. He believed that it has its origin in a very thin layer of subcapsular fluid, the thickness of which could not be over 0.2 p.
I have frequently seen a similar color display in cases of posterior saucer cataract.
After progression and thickening of the opacity, evidence of iridescence may be absent. A marked color display was noted by Vogt in cases of recent retinal separation with incipient but rapidly progressive cataracta complicata. With the ophthalmoscope many flat vacuoles were seen. Biomicroscopically they were localized just in front of the posterior capsule. The opacification at first was of little density but later the edges of these fluid spaces developed whitish porous opacities, and the typical rings appeared. The vitreous, as is common in these cases, showed a reddish-brown cellular infiltration and changes of structure. With development, and especially in older persons as is the case in posterior saucer cataract and nuclear cataract, the color of the opacities in this region may become increasingly )ellow.
The porous structure of posterior complicated cataract differentiates it from the changes usually found in cortical cataract - water slits, spokes, etc. (Fig. 419). The opacity tends to advance in two directions, spreading rosette-like to the periphery in the direction of the sutures so that the whole posterior subcapsular area of the lens becomes involved (like saucer cataract) and then spreading sagittally in the direction of the posterior adult nuclear stripe. The latter extension results in a considerable thickening of the opacity, especially in the polar regions. This type of irregular anterior extension into the posterior cortex differentiates complicated cataract from senile posterior saucer cataract whose anterior surface is sharply demarcated, since in this form of cataract progression forward usually does not occur. However, in the early stages, particularly in the absence of degenerative and inflammatory signs in the neighboring parts (which is rare) and based upon morphologic aspects alone, it may be difficult at times to differentiate between them. Posterior traumatic rosette opacities (page 1250) may occasionally present a problem in differential diagnosis. These, like posterior-saucer cataract (which ordinaril) does not assume the rosette form) are sharply demarcated. But traumatic rosette differs from both saucer-cupiliform cataract and complicated cataract in that it tends to be nonprogressive.
With development, the outspoken characteristic of cataracta com plicata becomes so obvious that its identity becomes unquestioned even to the beginner. The axial parts of the posterior cortex become filled with the large whitish crumblike irregular condensations which are especially thick in the polar regions, and from this radiating bands of the same porous nature extend toward the periphery where they become progressively thinner. These white crumblike structures within the opacity are suggestive of calcareous degeneration. The whole figure lies within a hazy medium. At times the opacity may become separated from the posterior capsule and may approach the posterior adult nuclear stripe. Within the central parts Vogt found ring forms and occasionally in the region of the posterior pole two or more ill-defined layers of opacity, one in front of the other, in which the anterior layer was the denser. Anterior subcapsular changes may appear early or late. Even in the early stages of cataracta complicata it is not unusual to find a few round vacuoles of varying sizes beneath the anterior capsule. However, these are often seen in senile cataracts as well. Later, fine flat subcapsular opacities appear; by retro-illumination and higher power these will be found to be composed of the finest vacuoles, the onset of gradually progressive anterior complicated cataract. Likewise, the appearance of nuclear cataract is common in the later stages.
Eventually, if the process advances sufficiently, in which case it is usually associated with progressive deterioration of the eye as a whole, a state of hypermaturity or shrinkage results (not unlike that of senile cataract) . This is particularly so in long-standing chronic iridocyclitis and absolute glaucoma in which the pupil becomes secluded and the iris very atrophic. The capsule becomes whitish and thickened by deposits and filmlike exudative membranes, and tends to develop the characteristic double reflecting folds. These folds may extend across the lens surface in parallel or crossed lines and at times may be outlined by pigment deposits. With extreme shrinkage of the lens, parts of a black pupil may become visible and occasional zonular fibers ma}â€™â€™ be seen stretched across it. Within the hypermature cataracts, calcareous changes and deposits of cholesterol crystals may be found.
Cataracts Associated with Endocrine Disorders
Clinicaliy there is considerable available evidence that endocrine dysfunction may lead to the development of cataract. Considering the present-day lack of information concerning the function and interrelationship of the ductless glands, it is not surprising to find confusion in the literature concerning the so-called "endocrine cataracts.â€ Bellows states: "Only in diabetes and parathyroid tetany is there a very solid foundation of experimental data to support the clinical observations. The cataracts observed in albinism, mongolian idiocy, gonadal insufficiency, myotonic dystrophy, neurodermatitis and scleroderma, although presumably endocrinal in character, have little experimental confirmation.â€ Even from the clinical standpoint, a great deal of statistical data is still needed. These will have to be coordinated with more exact morphologic descriptions of the changes, now possible with the biomicroscope.
At any rate, in these conditions (not dissimilar to complicated cataract in general) the opacities are found predominantly in the subcapsular middle portion of the anterior and posterior cortex, in most cases leaving the zones of disjunction unaffected. The appearance of the component parts of the opacities varies in individual cases but characteristically they are composed of whitish, discrete, fine, powdery, punctate dots, larger angulated spots, irregular flakes and occasionally iridescent opacities and crystals. In any one case, one type may predominate or several different forms of these constituents may be found to coexist in varying proportions. In addition thin flattened subcapsular vacuolar opacities spreading over a considerable area, not unlike those described in anterior complicated cataract (page ii6i) , may occur. It should be emphasized that, despite their characteristic location and appearance, all these types of opacities are not pathognomonic for any specific endocrine disorder. Similar ones may occur in other conditions, e.g., those resulting from the effects of radiant energy, toxins (drugs), and trauma. A point to be stressed is that apparently in most complicated cataracts the youngest
Fig. I. Diabetic cataract showing layers of anterior and posterior punctate opacities. 12-year-old girl. Direct focal illumination. Low power.
Fig. 2. Same case as shown in Figure i. Direct focal illumination. Optic section. High power.
Fig. 3. Diabetic cataract (rosette form). Woman aged 28.
Fig. 4. More advanced opacities in the diabetic cataract. Note dense central subcapsular opacity and cortical water clefts. Diffuse illumination.
Fig. 5. Same case as shown in Figure 4. Direct focal illumination. Optic section. Passing through the edges of the dense central opacity showing its subcapsular location. Cortical water clefts are not shown.
Fig. 6. Posterior subcapsular opacities (diabetic cataract) . Note color display in area of specular reflex and beginning nuclear haze.
subcapsular fibers of the lens seem to be vulnerable. However, one cannot deny the frequent occurrence of nuclear cataract (indistinguishable by itself from the common senile variety) in cases in which cataracta complicata would ordinarily be expected, but this form - with the possible exception of the diabetic cataract in older persons - is not typical for endocrine cataract.
As Duke-Elder has indicated, the striking clinical characteristics of endocrine cataracts in their pure form, although they frequently are complicated by other types, are the early onset, the bilateral incidence, and the zonular (layered) distribution.
At the present time the only type of cataract that justifies the appellation "diabetic cataractâ€ is the rapidly progressive one that is found in younger persons (under 40 years of age) and that at the outset is characterized by the presence of a layer of more or less dense small punctate or flaky opacities involving the anterior and posterior cortex beneath the capsule (Plate LXXII, fig. 2) . There is not sufficient experimental or clinical evidence at hand to evaluate how much of a role diabetes plays in the appearance of cataract (which clinically differs in no way from the ordinary changes of senile cataract) in the older age groups. As has been pointed out, a large percentage of apparently normal persons over 60 years of age show indications of lens changes of one kind or another. Therefore it is not surprising that in the past large numbers of ordinary senile cataracts were classified as "diabeticâ€ just because they were found in older persons having the disease. Also in these cases there seems to be no relationship between the duration or severity of diabetes and the onset or progress of the cataractous changes. However, as suggested by Vogt, it could be supposed that, in instances in which a person is "genetically predisposedâ€ to senile cataract, it could be provoked prematurely by diabetes. This author cites other conditions, e.g., senile corneal lines, arcus senilis, and coronary cataracts, as examples of conditions that may be prematurely provoked by outside influences (inflammations or toxins). Also to be considered is the idea that owing to the physiologic alterations (sclerosis, etc.), the "agedâ€ lens may be incapable of reactions morphologically similar to those occurring in the young. So that the same exogenous influences acting in the young might produce dissimilar pictures in the aged. Hence, in the aged there is perhaps a tendency for even cataracts caused by - exogenous toxins or even trauma to approach in appearance those of the so-called "ordinaryâ€ senile cataracts. Many theories have been advanced concerning the mechanism with which cataract could develop as a consequence of diabetes. Bellows summarizing the experimental evidence states: "Most writers attribute the opacity to osmotic or toxic actions of the excessive glucose and its metabolic products.â€ On the other hand, recently it has been indicated by several workers that many persons (not frankly diabetic ?) with ordinary senile cataracts have an inadequate mechanism for the utilization of sugar, and that "the incidence of hyperglycemia and decreased tolerance for carbohydrates was much greater than could be anticipated from senile changes alone.â€
Only those cases that occur in younger individuals (under 40 years of age) and that in many ways are morphologically similar to those found in other endocrine disturbances can be considered as true diabetic cataracts. Evidently the younger the diabetic person is in whom cataract appears, the more certain it is that we are dealing with diabetic cataract. Two chief features are to be noted in true diabetic cataracts: (i) their rapid development (usually bilateral) and (2) the subcapsular location of the opacities. Cases have been reported in which the opacification appeared within hours or days, and in one instance the lens became entirely opaque within 48 hours. This rapidity of development is similar to what occurs in certain toxic cataracts (page 1199). However, exceptions may be found. In the case of a 14-year-old diabetic girl (referred by Dr. Nemerson) on whom I performed a linear extraction, 4 years elapsed between the onset of the opacification and the time when operation became necessary. Her vision was reduced to 20/200 bilaterally. Forty units of protamine zinc insulin daily kept her sugar-free but apparently did not protect her from the slow development of the cataract. The
Opacities in the beginning resembled the typical anterior subcapsular "snowstormâ€ cataract described by Oâ€™Brien. These consisted of dots and flakes varying in size in one e)^e, the smaller ones seeming to col-" lect just behind the capsule but in this particular case they did not invade the space between it and the anterior stripe of disjunction (Plate LXXII, figs, i, 2). About a year later the opacities extended themselves in a gradual way into the middle and deeper parts of the cortex. Still later, posterior cortical opacities and, finally, a generalized nuclear haze ensued. The earliest changes seen by the writer occurred in a 28-year-old woman (Plate LXXII, fig. 3). They consisted of a single layer of glistening rosette opacities at the level of the anterior and posterior lines of disjunction. They were most marked in the peripheral regions and gradually faded out axialward. The rosettes were composed of shining dots which could only be seen by means of the optic section. They were invisible in strong diffuse illumination. Several months later, no change in their appearance was noted.
Vogt described the case of a 3 3 -year-old woman in great detail. Ophthalmoscopically an opacity extending over the whole lens surface was seen consisting of small whorls and stripes. Also by decentering the light as it transilluminated the pupil, many small spokes became visible. Biomicroscopically in optic section both lenses appeared thinner than normal in sagittal direction, but in the left lens the cortex seemed to be thicker than normal. The zones of discontinuity were poorly outlined. The mass of opacities was located under the anterior and posterior capsule centrally and peripherally as far as it could be inspected. The opacities anteriorly were gray, cloudy and transparent while posteriorly they were flat, white, and compact, differing in this way from the porous opacities of posterior cataracta complicata. In the left eye the posterior opacity in the region of the pole measured about i mm. vertically and 2 mm. horizontally. While in the right (Fig. 421) the denser posterior ones were from 0.2 to 0.3 mm. in diameter. Elsewhere the subcapsular
â€¢ â€™ 46 ^ ^ observation in that he found that this space is usually
involved. When the space between the capsule and the anterior stripe of disjunction is invaded, granular opacities may project into it and obliterate the stripe. When this occurs fluid (vacuolar) may occupy the area between the capsule and these opacities.
BIOMICROSCOPY OF THE EYE
opacities were mostly dot- or dustlike and invaded the deeper parts of the cortex. Occasionally colored glittering crystal line structures were seen in the neighborhood of the anterior mirror region. Vogt
Fig. 421. Diabetic cataract. A . Right eye. b. Left eye. (After Vogt.)
also noted the appearance of opacities outlining the superficial fiber design. These speak for the involvement of the superficial cortical fibers. In places they were interrupted by lanceolate gaps and in the deeper cortex traces of water slits were seen (Fig. 421.)
As the formation of the fiber design develops, cortical vacuolization and opacification increases so that in the end the subcapsular punctate opacities are replaced by radiating opaque granular masses separated by irregularly dark lancet-like spaces. This picture, which is especially characteristic in the frontal view by diffuse illumination, can also be seen against the reddish glow of the fundal reflex ophthalmoscopically. By the latter method illuminated gaps (water-slits) between irregular darker outlines (radiating opacities) are visible It should be pointed out that subcapsular fiber design can also occur in complicated cataracts from other causes (e.g., tetany, myotonia, trauma, and toxins) . It merely illustrates the fact that in cataracta complicata the youngest fibers are the most vulnerable. Localized, subcapsular star-formed opacities may occur especially in the polar region (Fig. 420; Plate LXXII, fig. 3) . In a recent publication, Rosen considered that the presence of the so-called
"diabetic needleâ€ or "Roman numeral sign.â€ According to Rosen, this sign is not constant but, when present, is specific for diabetes. He states that, "Characteristically when the pupil is dilated and when the red reflex is studied with the indirect ophthalmoscope or retinoscope, a spoke formation is seen in the periphery of the lens, which is a linear black streak no thicker centrally than if is peripherally. This is its most important feature - the spoke is never thicker at the periphery than at its central termination and even in cases where there is adult spoke formation in the lens characteristic of early change in senile cataract, still there may be superimposed upon this cataract formation, the characteristic diabetic needle.â€
In his description and illustrations Rosen does not give any biomicroscopic descriptions of these "needles.â€
In the main, Vogt emphasized that the characteristic picture of diabetic cataract consisted of anterior and posterior subcapsular clouds and dustlike opacities extending over the whole lens surface and tending to condense into greater complexes. In addition it is distinguished by opacities that bring out the superficial fiber design of the fibers, by the formation of small water-slits between the fibers, and by an extended subcapsular vacuolar degeneration.
The appearance of subcapsular fluid vacuoles as an early finding has been stressed by many other authors. It is assumed that the opacities develop from them.
Ephemeral Diabetic Refractive Changes. It is well known that with the onset of diabetes sudden changes in refraction may ensue. Either myopia or hypermetropia may appear suddenly in a person whose refraction formerly was emmetropic, or these changes may be added to an already existing error of refraction. Hence, a sudden unexplained change in refraction (especially myopia) in adults should be looked upon with suspicion. "With treatment, the myopia may or may not disappear. When it does, as is usual, the individual may first pass over into a condition of hyperopia or if previously myopic, to a state of less myopia before returning to
- This term was applied to these opacities because of their resemblance to the employed in designating Roman numerals.
BIOMICROSCOPY OF THE EYE
his original status. If the initial change is one of hyperopia (which statistically is more common), it tends to appear with decrease in glycosuria and in younger individuals is accompanied frequently by systemic weakness. Without dwelling on the theories offered to explain the phenomena of refractive changes in diabetes (e.g., accommodative paresis and changes in refraction in the other ocular media) it should be pointed out that most authorities have attributed these changes to refractive alteration of the lens. Because of this, several writers have studied the lens during the course of a sudden change in refraction to ascertain whether there were any visible alterations biomicroscopically. The results were uncertain. I recently saw three cases, all women, aged 28, 32, and 54 respectively. In the younger two, the changes consisted of the sudden appearance of myopia and in the older one, hyperopia. The refractive change in the 2 8 -year-old woman, who previously was emmetropic, appeared within 2 days and was the first known symptom of her diabetes. During these 2 days a gradually bilateral progressive myopia reaching three diopters developed. Insulin therapy was instituted 3 days later, and within a week the myopia began to recede. Two weeks following the onset of the myopia, the refraction was again normal. She did not pass over into hyperopia. In the second case, the interesting feature was that i diopter of myopia suddenly developed in the right eye and only 14 diopter in the left. Three months previously under cycloplegic refraction, she accepted +0.50 cylinder axis 90 degrees in both eyes. Six months later, with the diabetes controlled by 15 units of protamine zinc insulin daily, these was no diminution in the myopia. In the third case - the eldest of these three persons - the patient suddenly noticed marked blurring in her distant vision as well as being unable any longer to read with her usual presbyopic correction of +2.25 sphere in both eyes. She now required a +3.50 sphere bilaterally for distance and + 5.00 sphere for near vision. Three weeks following stabilization of her diabetes the hyperopia disappeared. About 6 months later she again showed a transitory increase in hyperopia associated with
According to Granstrom^Â® this is rare over 30 years of age.
COMPLICATED CATARACT 1185
a return of a high degree of hyperglycemia. Her insulin dosage was increased markedly and within lo days her hyperopia again abated. During the last year there have been no refractive changes.
I took special pains to examine these cases biomicroscopically at frequent intervals. In the first case, the anterior cortex (using the thickness of the corneal optic section for comparison) appeared thicker during the period of myopia than later. I was unable to convince myself of the presence of any definite blurring of the stripes of discontinuity or any increases of relucency in the cortex or nucleus.'*' In the other two cases I could not observe any biomicroscopic changes in the lenses either during the period of refractive change or afterward. In a case described by Vogt, a 44-year-old man, previously emmetropic, developed 3 to 4 diopters of myopia; a blurring of the bands of discontinuity (adult nuclear and fetal nuclear stripes) was observed. There was no increase of nuclear relucency as is the case in a lens with double focus. The chamber depth remained constant. With lessening of the myopia, the increased visibility of the zones of discontinuity become noticeable. At times Vogt had the impression that the sagittal thickness of the lens was increased. If the myopia results from increased difference of the index of refraction between the nucleus and the cortex, i.e., owing to decrease of cortical index or increase of nuclear index, then the zone of discontinuity should be more refractile. It could be hazarded that with the increase of cortical thickness, its action as a negative meniscus becomes less as compared to the positive action of the enclosed nucleus.
TETANY CATARACT ( CAT AR ACTA PARATHYROPRIVA)
The association of tetany and zonular cataracts has already been mentioned in the chapter on developmental cataract. This type of cataract is by no means pathognomonic when observed in cases of spontaneous tetany (Figs. 383, 384). However, it may well be
Examination of this patient 18 months after the initial episode of the myopia revealed no refractive changes. However, biomicroscopically a single layer of delicate punctate glistening opacities at the level of the anterior and posterior lines of disjunction appeared. These seemed to develop peripherally and gradually faded out axially and evidently represent the first indications of the onset of a diabetic cataract.
that cataract of the zonular type is more characteristic for the cases in which tetany develops prenatally or in the first years of life, while those which occur later (whether they are spontaneous or follow operative damage or removal of the parathyroids) tend to be of the subcapsular type. In two recent cases in young persons called to my attention, the opacifications appeared as the typical complicated subcapsular variety similar to that seen following inadvertent parathyroid damage in thyroidectomy. The fact that cataract in spontaneous tetany may be similar to that in postoperative tetany (tetania strumipriva) was pointed out by Vogt who described the first biomicroscopic picture of tetany cataract in 1921. In the two spontaneous cases just mentioned, one occurred in a 1 2-year-old girl and the other in a 20-year-old woman, 3 months postpartum. In the latter, case, treatment by Dr. Werner with dehydrotachysterol prevented tetanic attacks for the one and a half years of observation but no diminution in opacity of the lens was noted (Fig. 422 A, B, C). The vision remained unchanged at 20/80 in each eye until both lenses were removed by linear extraction. In the former case frequent tetanic attacks started just after the menarche. The vision was 20/50 in the right eye and 20/40 in the left. There were definite signs of previous hypoplasia of the enamel of the teeth and slight indications of past rickets. Therapy with dehydrotachysterol had just been started at the time of writing so that no definite conclusion concerning its effect on the progression of the opacities is as yet possible. It would be interesting to try this therapy in cases at the time of the earliest appearance of the lens opacities, especially in the light of Goldmannâ€™s experiments (discussed later) . However, the difficulty in obtaining early spontaneous cases with lens opacities is great, since the condition of parathyropriva is not always recognized immediately.
The opacities in both cases were similar morphologically to those described in other endocrine cataracts (diabetes, myotonia atrophica). Nuclear cataracts and even total cataracts have been reported in tetany. According to both clinical and experimental evidence, it is known that the basis for tetany (both spontaneous and postoperative) is h^'^pocalcemia. Experimentally in animals the
effects of parathyroidectomy on the prodution of tetany and cataract has been established. Goldmann showed that the tetanic convulsions and the rate of formation and regression of lens opacities (the appear A B
Fig. 422. Tetany cataract (cataracta parathyropriva). a. Right eye, diffuse view. B. Left eye, diffuse view. c. Direct focal illumination (optic section showing location of opacities).
ance of which is dependent on the attacks) could be controlled by the administration of calcium. Goldmann concluded that "cataract resulting from muscular tetany is not a chronic condition but a rapid, acute poisoning of the lens fibers. The toxic action is shortlived so that only the superficial layers are attacked. If the attack
BIOMICROSCOPY OF THE EYE
is not repeated, lens turbidity may regress; if repeated, the fibers may be irreparably damaged and death supervene terminating in a total opacity of the affected area.â€
The typical location of the opacification of cataracta parathyropriva is subcapsular. This is, as described above, also found in juvenile diabetic cataract, cataract of myotonia atrophica, and cataract resulting from the action of exogenous toxins or physical agents. Consequently, the presence of this type of subcapsular opacification does not, of itself, permit an etiologic diagnosis. A thorough survey of the pertinent history and physical findings as well as laboratory studies must be instituted. However, Vogt stresses the point that the conspicuous appearance of the fiber design of the cortical surface (as sometimes occurs also in diabetes) is a typical finding and should cause one to be suspicious of tetany cataract. This would be particularly so in cases in which there is a history of a previous thyroidectomy. In the literature, there seems to be a wide divergence as to the time of onset of lens opacities following the operation, vary^ ing from a few months to ^ears. The majority of cases developed subcapsular cataract, as long as 20 years following thyroidectomy. However, whether this was a result of the thyroidectomy is questionable, since the possibility of the appearance of coincidental presenile or senile cataract formation arises. Especially since it is known that in some cases the latter may begin subcapsularly and may resemble anterior cataracta complicata (e.g., anterior saucershaped or cupuliform cataract). Morphologically the opacities in tetany cataract may start with the presence of subcapsular dustlike dots or flakelike structures, with occasional iridescent crystalline formations. In the vacuolar type the development is similar to that described under the heading of anterior complicated cataract. In the latter type of tetany cataract, the fiber design is common, and the opacity itself is thin and tends to form irregular radiating bands in the direction of the suture system. "With time, progression of the subcapsular opacities may result in complete opacification of the cortex, presenting a white pupil or â€œtotalâ€ cataract.
^ Quoted from Bellows.^'^
Cataract of Myotonia Dystrophia (Myotonia Atrophica)
After Thomsen reported the symptoms of myotonia congenita (myotonia without atrophy) in 1876, Erb (1886) described atypical cases of myotonia with muscular atrophy. However, it was not until 190^, that both Batten and Gibb and Steinert formulated the syndrome of myotonia atrophica as an entity characterized by atrophy of certain muscle groups associated with active or passive myotonia, i.e., a tonic spasm of certain voluntary muscles with slow relaxation. The classic example of myotonia atrophica is the inability to open the closed fist. Atrophy of muscle groups, e.g., facial, masticatory, and flexors of forearms and feet, etc., incapacitates these patients, the result of the first being masklike facies. Symptoms of this disease may become manifest just before or after puberty but in most instances they appear between the ages of 18 and 30 years. The average span of life is short. The condition is unquestionably hereditary, appearing as a dominant character. According to Allen and Barer,'^'* "Although the etiology is unknown, Fleischer has shown dystrophia myotonica to be a heredofamilial degenerative disease exhibiting anticipatory signs through several generations before it develops in its entirety in one generation. These anticipatory signs are: frequent instances of celibacy, many childless marriages, high infant mortality rate, and cataracts. In earlier generations cataracts develop at an earlier age, until in the 'myotonic generationâ€™ they are definitely presenile.â€ Most authors consider that endocrine dysfunction is the basis of its pathogenesis.
In addition there is the tendency to loss of hair, disturbance of the salivary and sweat glands, loss of body weight, atrophy of the gonads, as indicated by early cessation of menses and testicular atrophy and impotence, and finally cataract. The appearance of cataract, first noted in this condition by Greenfield (1911),^â€œ'â€™ may be one of the earliest extramuscular symptoms and is so persistent and significant that its presence is now regarded as an important point in differential diagnosis. Earlier writers ascribed a lower percentage of cataract (10 to 30 per cent) to this condition. Such a low incidence may have resulted from the inclusion of allied neuro
BIOMICROSCOPY OF THE EYE
muscular disorders (e.g., myotonia congenita or amyotonia congenita), all of which do not exhibit cataract formation.
Recently I had the opportunity of examining biomicroscopically the eyes of 72 cases of muscular dystrophies collected by Dr. A. Milhorat from the Medical Service of the New York Hospital. The results are presented in the accompanying table.
APPEARANCE OF CATARACTS IN CERTAIN MUSCULAR DISEASES
Periodic family paralysis
Amyotrophic lateral sclerosis
The tw,â€™o patients without opacities (of these one patient has a brother with no symptoms of myotonia atrophica but with typical lens opacities) had very mild symptoms, and the diagnosis of myotonia atrophica was doubtful. In the one patient with cerulean opacities, the case was unusual in that there was also peripheral neuritis.
COMPLICATED CATARACT 1191
A study of this table shows that the deep subcapsular variety of cataract is not only peculiar to m^'^otonia atrophica but that it was found in practically every proved case. These findings are in accordance with those reported by Vogt (1922) Waring, et al. (1940) Allen and Barer (1940),^'*â€œ Sautter (1941),^'â€™^ and others.Â®'â€™Â®â€™
The earlier descriptions of the lens changes in myotonia atrophica by Fleischer, Hauptman, and von Szily - as well as later by Allen and Barer - stressed the frequent appearance of a rosette in the posterior cortex."' With this they described the presence of senile white punctate opacities in both anterior and posterior cortical layers. Later in association with white punctate, angular or linear spots Vogt added another finding, i.e., smaller red or green iridescent dots, which were present in nearly all of his cases. The fact that in some cases there were well-formed crystals resembling cholesterol in the adult nucleus led to the supposition that the smaller colored dots (admixed with the larger white ones) were of the same substratum. However, an occasional colored dot may be seen in the cortex of normal lenses as well as in those having senile cataract or in tetany cataract. Vogt states that we should think of the possibility of myotonia when these colored dots are found in the anterior or posterior cortex in a greater number, particularly when they are associated with white angulated dots. The presence of all these opacities in the form of a dense layer, usually deep in the cortex, leaving the anterior line of disjunction and superficial cortical regions unaffected, tends to give the deeper parts of the lens a veiled appearance and often obscures the inner zones of discontinuity. In two of our cases there were a few isolated subcapsular vacuoles; the superficial fiber striping or design, so common in the cataracts of tetany and diabetes, is not characteristic of myotonia atrophica
The presence of a rosette or starlike figure in the posterior cortex is by no means a universal finding in this condition. In the six cases which I recently examined, it was not found once, even in cases of long duration. Allen and Barer found that the earliest changes occurred posteriorly and consisted of minute white opacities and iridescent crystals and that they tended to concentrate along the sutures in a stellate manner. According to their findings the lens opacities seemed to progress in direct relationship to the rate of progression of the muscular symptoms. Cases showing rapidly developing muscular symptoms were accompanied by an earlier development of a totalâ€ cataract. In only one of their cases did the opacities first appear in the anterior cortex.
1192 BIOMICROSCOPY OF THE EYE
(Fig. 423). With progression, which is usually slow, water-slits and lamellar separations develop, which in the end lead to maturity of the cataract. The axial concentration of the typical opacities and
Fig. 423. Cataract in myotonia atrophica. Anterior and posterior subcapsular punctate opacities.
iridescent dots should differentiate myotonia cataract from coronary and cerulean cataract, although the later may often be present fortuitously, considering that its incidence has been computed as high as 25 per cent in otherwise normal individuals.
Cataract Associated with Mongolian Idiocy
The high incidence of cataract in Mongolian idiocy has been recorded by numerous observers. Bellows, compiling the statistical evidence of both Ormond (1911-1^12)^^' and van der Scheer,^â€™â€™Â® points out that cataract occurred 61 times in 102 of their cases (59.8 per cent). They found cataract only once in a person under the age of 8 years. According to Koby who published the first bio ' Although this might suggest that the cataractous changes are acquired rather than of congenital origin, it does not entirely preclude a hereditary tendency, in the same sense as in other opacities appearing during childhood or early youth (cerulean or coronary). However, in the present state of our knowledge dogmatism concerning the etiology of juvenile cataract is not justified. As previously mentioned, the recent reports on the finding of
microscopic description of catnrnct in Mongolian idiocy in a 17year-old girl, lens opacities rarely appear before the fifteenth 5^ear. In his case the bands of discontinuity were fairly clear. There were
Fig. 424. Cataract in Mongolian idioc>'. (After Koby.)
two t5pes of multiple opacities: the flattened type, which were yellow and blue in color, similar to those in cerulean cataract, and the fine crystalline type showing green and blue iridescence not unlike those of cataract parathyropriva and myotonia atrophica. The opacities occupied the deeper cortex and parts of the adult nucleus, leaving the embryonal nuclei unaffected. From the descriptions in the literature, the morphologic appearance of cataract seen in Mongolian idiocy varies from case to case. This variance may depend on the fact that, having progressive tendencies, the appearance and localization of the opacities changes with age. The distribution and the typical punctate to flocculent character of the opacities may be suggestive of endocrine dysfunction as the etioiogic factor (Fig. 424). As a rule, the opacities are denser axially, while in a more scattered fashion they may occasionally extend peripherally around the visible equatorial region. OrmondÂ®Â®'^ published illustrations in which the opacities formed a ring leaving the axial region free. Fre cataract in the newborn whose mothers had German measles during their pregnancy indicates the possibility of exogenous influence. Likewise the effect of endocrine dysfunction, or of nutritional and dietary deficiencies on production of lens opacities, especially in theâ€™ young still requires clarification.
BIOMICROSCOPY OF THE EYE
quently they are more numerous in the posterior cortex than in the anterior, and they assume a radiating disposition. Duke-Elder in describing the opacities stated: "Some are powdery and punctate, some annular and some flaky; while others have a crystalline appearance. The majority are white, while others glitter with red or green light.â€
In addition to these cortical opacities, essentially similar to those found in myotonia dystrophica, van der Scheer has called attention to the finding of suture cataract (fetal [especially the anterior Y] and at times cortical) as an essential part of the lens changes in Mongolian idiocy. This change was not found in most of the cases cited in the literature by other authors. However, the frequency of occurrence of suture cataract in normal individuals should be considered. Hence suture opacification is probably not an essential feature of cataract associated with Mongolian idiocy but, when present, is probably coincidental.
Cataract Associated with Certain Skin Diseases (Cataracta Dermatogenes)
The complication of presenile cataract in certain chronic diseases of the skin has been pointed out by numerous observers since the original observations of Rothmund (1869) Most of the cases described occurred with neurodermatitis. Less frequently they have been reported in scleroderma (as part of Wernerâ€™s syndrome) or in polikiloderma atrophicans vascular (Rothmundâ€™s disease) and eczema. It is not surprising that in certain conditions in which the ectodermal tissues are primarily affected (skin, hair, nails, teeth, etc.) that the lens participates. At the present time there is no unanimity of opinion regarding the etiology of these skin diseases in which cataract may sometimes appear. In all these syndromes, dysfunction of the endocrine glands has been suggested but the evidence is inconclusive. Allerg}â€™- has been advanced as a basis of the pathogenesis especially in the case of neurodermatitis b)'^ Daniel,Â®'â€™^ Brunsting,^'" and Beetham.Â®*^^ Both Wernerâ€™s and Rothmundâ€™s disease have a familial tendency, the latter being transmitted as a recessive char
acteristic. The descriptions of dermatogenous cataract, in the literature, vary considerably. However, while there are certain characteristics that seem to be common to them, they are in a broad sense
common to all the opacities found in endocrine dyscrasias (Fig. 425 ) . These common characteristics are as follows: the opacities in the beginning are subcapsular and frequently follow the radiating design of the sutures; others tend to appear in the form of rosettes. In some cases the development of a central capsular opacity was noted. Vogt described a case occurring in a 2 8 -year-old man, who since early youth had neurodermatitis. He had a milky lens with a denser irregular capsular opacity (resembling a plaque or shield) in the axial region. The plaque measured 3 mm. vertically and 3.5 mm. horizontally, and this practically filled the pupillary area. The edges of this capsular opacity were scalloped in an uneven concave manner and showed shagreen-free areas, demonstrating a change of level in the capsular curvature. In the right eye there was also an incipient anterior complicated cataract in the form of a rosette; the radiating opacities were subcapsular and in places a fiber design was apparent. The posterior cortex in both e^^es at this time seemed unaffected. The vitreous structure was disturbed and contained numerous brown pigment granules. Three months later examina
BIOMICROSCOPY OF THE EYE
tion of the right eye showed an oval capsular opacity not unlike that in the left eye in which gaps in the shagreen reflex were found at the margins. The posterior cortex in this eye now showed a cloud of opacities axially. The change in curvature of the anterior capsule at the border of the capsular opacity can be demonstrated by the narrow beam where an actual depression or concavity results. This type of capsular alteration can occur also in hypermature cataracts both in the senile variety as well as in the complicated form. Both Lowenstein and Andogsky described similar forms of cataract in neurodermatitis. Andogsky described four cases in young persons in whom the cataract began as an anterior subcapsular rosette opacity. Recently I saw and operated on a case of precocious cataract in a young man, aged 28 years, who had marked neurodermatitis of the face and extremities. The lens opacities were bilateral and consisted of dense subcapsular radiating opacities, anterior and posterior. There were numerous subcapsular vacuoles. No axial capsular opacity was found, but there were several small flat ones distributed more peripherally in an uneven way. In the right eye the vision was reduced to 20/100, and this could not be improved. The vision in the left eye was 20/40+ with a â€œ0.75 sphere. He was under observation for three months prior to the time cataract extraction was performed. During this time there was no change in visual acuity. In a case of Wernerâ€™s disease (scleroderma),"' reported by Agatston and Gartner,^^'^ occurring in a 3 8 -year-old man, whom I had observed for six years and on whom I had performed a cataract â€¢ extraction in the left eye in 1937, there were typical findings of dermatogenous cataract. When first seen, this patient had anterior and posterior delicate subcapsular opacities in the axial regions of both lenses, more marked in the left eye (Fig. 426 ). There were numerous subcapsular vacuoles anteriorly. The opacities radiated in a manner suggestive of a rosette. In the periphery of both lenses
At 32 years of age this patient already had the appearance of an old man. Partially bald, his hair was gray and the skin over the face and extremities was inelastic, thickened, and brownish in color. He was slight in build with small hands and feet. His teeth were carious. The configuration of the pubis and the arrangement of the pubic hairs were feminine. The penis and scrotum were small, all indicating a possible endocrine disorder.
COMPLICATED CATARACT 1197
there were scattered coronary opacities. At this time bilateral iridectomies were performed. There was little progression of the opacities or loss of vision during the next five years. In the sixth year the
Fig. 426. Cataracta dermatogenes. Early changes. (Case of Agatston and Gartner.)
vision in the left eye began to fail, becoming reduced from 20/50 to 20/200. With the biomicroscope, the disintegration of the cortex was seen. Water-slits with spokelike opacities formed. In the posterior cortex there was a saucer-like opacity. The lens was extracted extracapsularly. The right eye was unchanged, vision being 20/40 unimproved. About a year later the cataract matured in the right eye and was removed by Dr. S. A. Agatston. According to the report of Agatston and Gartner: "Both eyes had operative colobomas of the iris above. The right eye had a cataract which matured in a few months. When the patient was first seen he had posterior cortical opacities, some subcapsular vacuoles and anterior peripheral cortical opacities.â€
Since the original communication of Bouchard (1886) in which he showed that cataracts could be produced in rabbits by feeding them naphthalene ( i gram per kilogram of body weight) mixed with their daily diet, numerous investigators have corroborated experimentally as well as clinically that opacification of the lens may follow in the wake of toxic effects resulting from the in
BIOMICROSCOPY OF THE EYE
gestion or inhalation of certain poisonous substances. Especially prominent among these poisons are ergot and thallium and benzene and phenol derivatives such as phenol, naphthalene, dinitrophenol, dinitro-orthocresol, and paradichlorbenzene. Also experimentally in rats, lactose and galactose feedings have produced lenticular opacification. Bellows summarized the findings as follows: "The susceptibility to cataract formation following poisoning by these substances shows marked differences in the various species. Poisoning by dinitrophenol or ergot produces cataract in man but has never produced cataract in lower animals; naphthalene poisoning produces cataract in rabbits (Bouchard and Charrin) and in man (Lezenius'â€™â€^; thallium induces cataract in rats but not in man; and thus far galactose cataract has been reported in rats only. Not only do the species differ in their response to these various poisons, but there is a marked individual susceptibility within certain species.â€ I found a similar selectivity in the case of paradichlorbenzene poisoning in which cataract followed the inhalation of the vapor from this substance in humans and not in animals, although in both there were manifestations of toxic hepatitis. In humans, in most cases the appearance of toxic cataract (dinitrophenol, naphthalene - in one case reported b)^ Lezenius, paradichlorbenzene and ergot) was characterized by a rather long latent period, i.e., the lens changes ordinarily do not appear immediately after the poisoning. In most cases the latent period extended over a year. For example, in an epidemic following the ingestion of rye harboring an ergot-containing fungus, Tepkjilaschin noted that cataract did not occur until from 2 to 5 years after the poisoning (27 cases). Likewise in dinitrophenol poisoning Rodin (2 cases) noted that the average latent period was about 15 months. In the two cases of cataract that I described following the inhalation of fumes of paradichlorbenzene, the incidence of the lens changes occurred 12 months
As a result of the work of Bourne, Young and Stekol (cited by Bellows) the mechanism of naphthalene cataract formation may be reconstructed as follows: Naphthalene is detoxified in the body by conjugation with C3â€™steine to form a mercapturic acid derivative. All tissue, including the lens, suffer a reduction in cjâ€™steine proportional to the amount of drug ingested. With the loss of q-steine the respiration of the lens (which is an avascular tissue) must suffer and if sufficiently interrupted, the lens must die with resulting opacification.
COMPLICATED CATARACT 1199
(bilateral) and about 7 months (uniocular) respectively after the patients were removed from the noxious fumes. The prolonged latent period and the rapidity with which the toxic cataracts develop after once having started have not yet been explained.
In the case of dinitrophenol poisoning there is some available evidence that w vitro the increase in metabolic rate and consequent depletion of the available oxygen may be a factor in the production of this form of toxic cataract. Because of the hepatic damage associated with toxic cataract, Berliner, following Onfray and Dreyfus, suggested several ways in which hepatic damage might be related to cataract formation. However, conclusive evidence of this relationship is still lacking.
The lens opacities in toxic cataract tend to start subcapsularly in forms not unlike those seen in endocrine cataract, viz., with punctate and vacuolar changes either descrete or in the form of rosettes and also with iridescent crystals. However, unlike the slower development ordinarily seen in complicated cataract, in most cases the process in toxic cataract is characterized by a more rapid progression. This is evidenced by quick cortical swelling and disintegration. Large water-slits and laminary separations are soon followed by complete opacification or maturity of the cataract. In one of the cases of paradichlorbenzene poisoning, mentioned above, within a week the vision failed from 20/10 to the perception of fingers at 3 feet. The anterior chamber became shallow, and intraocular pressure increased so that extraction became urgently necessary. When first seen, 3 or 4 days following the onset of sudden visual blurring, the vision in the right eye was reduced to 20/70. At this time there already was considerable swelling of the cortex. There was a subcapsular layer of fine punctate opacities and vacuoles. Beneath this in the anterior cortex, which was hazy, there were many large water-clefts, and in the periphery, areas of laminary separation. The nucleus was faintly relucent. Through the haze a slightly yellowish granular opacification, which in specular reflection revealed several glossy iridescent dots, could be just made out subcapsularly in the posterior cortex, reminiscent of posterior complicated cata
BIOMICROSCOPY OF THE EYE
ract. Within a few days no further details could be discerned in the nucleus or posterior parts of the lens owing to the total disintegration of the anterior cortex (Fig. 403 A, B) . The condition in the left eye followed the same rapid course. In a case of ergot poisoning, Cattaneo reported the findings of anterior and posterior subcapsular rosette-like formations. Whalman,Â®'Â® who tabulated the findings in 27 cases of dinitrophenol cataract, stressed this rapid development and bilaterality and summarized their clinical appearance as follows : "Study of these cataracts with the biomicroscope revealed certain characteristic changes wliich appeared in all instances. There is no abnormality in the cornea. The aqueous humor shows an increased flare. The anterior capsule of the lens is at first spotty, dry and lusterless, and later somewhat pebbly, while beneath the capsule fine gray cloudy opacities appear. Still later irregular pearl-gray opacities appear in the deeper layers of the cortex. Concurrent with the early changes in the anterior portion of the lens, a polychromatic luster can be seen in the zone of specular reflection in the posterior cortex. These alterations are followed by a marked swelling of the lens, and the embryonic suture lines seem to be completely shattered by dark spaces resembling water clefts. If the condition is seen later than this there is almost complete disorganization of the lens and nucleus.â€ In one case - that of a 48 -year-old woman - I found bilateral nuclear cataracts with incipient cortical changes. The blurring of vision began 6 months subsequent to a course of "reducingâ€ therapy in which thyroid extract was alternated with the administration of dinitrophenol. During a period of 6 weeks in which she lost about 22 lbs. of body weight she took approximately 15 gm. of desiccated thyroid and about 20 gm. of dinitrophenol. Disregarding this medication and sudden onset of the lens opacification, morphologically this cataract could easily have been mistaken for an ordinary senile cataract.
In an analysis of the reported cases, the amount of the dinitrophenol or the length of time which it was administered seemed to bear no definite relationship to the onset or progression of the cataracts. In one of Whalmanâ€™s cases cataracts appears 3 months
COMPLICATED CATARACT 1201
following the daily ingestion of 300 mgm. during one month only. Three weeks after their onset they became mature.
Cataract Associated with Glaucoma
The association of cataract with glaucoma has been known for a long time, particularly the form that occurs in absolute glaucoma (in blind e5es where, owing to iris degeneration, the pupil is wide) and it is characterized by a distinctive porcelain white, yellow, or greenish hue."'â€™ In 1879 Priestley Smith described this type of cataracta glaucomatosa, which usually starts with nuclear opacification and is frequently accompanied or followed by posterior saucer opacities and cataracta complicata. Gradually the cataract becomes total, eventually passing over to the hypermature state in which shrinkage occurs (as evidenced by capsular folding, and deepening of the anterior chamber) . At times following zonular stretching or rupture, dislocation results. Secondary chalky and crystalline degenerative changes are often manifested. In some cases, especially when the lesion is extensive, iridic adhesions are present, disintegration and absorption of lens material may lead finally to a condition in which only a folded membrane is seen in the pupillary area.
Besides this form, biomicroscopic examination of the lens in glaucoma, especially in chronic cases in which surgery has been resorted to, will almost invariably reveal lens changes. These may vary from small capsular and subcapsular opacities, frequently localized to the segment corresponding to the operative procedure (iridectomy, iridocleisis, cyclodialysis, or trephine) to more extensive cortical or nuclear cataract. The rapidity with which these opacities follow surgery would suggest that they are in all probability directly or indirectly related to it. As in traumatic cataract, localized subcapsular opacities may form; and when rapid swelling of the cortex ensues, a mature total cataract results. In the latter instance rupture of the lens capsule may occur either as a result
Before glaucoma was known as an entity a distinction was made between gray and green cataract. The latter was deemed inoperable.
BIOMICROSCOPY OF THE EYE
of instrumentation (particular!}'- when the anterior chamber is shallow) or spontaneously (the posterior capsule being especially vulnerable) following sudden decrease in intra-ocular pressure
Fig. 427. Disseminated cataract after glaucoma. A layer of opacities seen three months following iridectomy (not present before operation). Cortex wider than normal. Beginning nuclear opacification.
on opening of the anterior chamber. A variety of other causes could account for the appearance of a rapid cortical swelling and disintegration, even if it were possible to rule out actual rupture of the capsule, e.g., increased capsular permeability, or the action of toxins or other factors initiated within the lens itself (Fig. 427).
Under the designation cataracta dissemiiiata subepitheJidis comatom acntdâ€™ or ^^white gJaucovia spots of the lens,â€™â€™ Vogt (1930)Â®â„¢ described the sudden appearance of multiple sharpl};" circumscribed white subcapsular opacities seen only after an attack of acute glaucoma. At first he thought that these opacities were conditioned by the operative procedure (following the sudden reduction in intra-ocular pressure) , since they were seen after iridectomy.
But later, he found the same type of spots in unoperated cases of acute glaucoma that were controlled by miotics. In optic section the thickness of the opacities is uniform and, being thin, they tend to lie
Fig. 428. Disseminated subepithelial cortical cataract of acute glaucoma, a. Diffuse illumination. B. Optic section. (After Vogt.)
in one plane parallel to the surface. They vary in size (from 0.3 to 0.02 mm. or less) and in shape are principally roundish or angular. Predominantly these spots are found in the axial region, where they string out in the direction of the suture lines (Fig. 428 A, B). According to Vogt their surface has a smoothness, reminding one of polished ivory. Characteristically the spots, which appear within days or weeks following an attack of acute glaucoma, are subcapsular, the shagreen of the capsule over them not being interrupted. This together with the radial direction of their extension (in one plane following the direction of the cortical sutures) suggests that they are
BIOMICROSCOPY OF THE EYE
not related to the anterior capsule in the sense of deposited exudative spots or to the denudation of the underlying epithelium. Within short periods of time (weeks to months) the narrow beam will disclose that these spots tend to be displaced deeper into the cortex. As in polar cataract and in certain types of traumatic opacities,"' the ingrowth of new lens fibers subcapsularly serves to push these opacities back so that with time a lucid interval of increasing width is observed between them and the anterior line of disjunction. In one case the subepithelial opacities, which were noted immediately following an acute attack of glaucoma, after five years were seen to be located in the neighborhood of the adult nuclear surface. The opacities do not seem to enlarge with time but in the main either remain stationary or in some instance fade or become smaller. In another case described by Vogt, typical subcapsular opacities were seen in a case of acute glaucoma one week post-operatively. The following day it was observed that they were already smaller in size. This might indicate that they are capable of being absorbed when fresh and when located in their original subcapsular location. Later the possibility of partial absorption seems to be less, especially after the opacities have pushed into the depth of the cortex by the ingrowth of newly formed healthy fibers. In all instances, the posterior cortex never showed any similar foci or other characteristic findings. The fact that these spots have not been noted more frequently in cases of acute glaucoma that were treated by miotics might be explained by the suggestion that once the attack is over and the pressure is controlled it is rare for a physician to hazard dilatation of the pupil for diagnostic purposes only.
Considering the uniformity of the picture in which small intensel}'" white subcapsular flat opacities are seen following attacks of acute glaucoma Vogt considers cataracta disseminata subepithelialis anterioris to be a distinct and separate entity. In view of the acute onset of these opacities - viz., following an attack of acute
Similar opacities have been noted following severe contusions. In these cases an increase in intra-occular pressure (although of shorter duration) may be a factor in the genesis of the opacities.
COMPLICATED CATARACT 1205
glaucoma - one might not be incorrect in calling this entity an example of '^acute cataract.
Fjg. 429 Deformation of the lens by a tumor.
Deformations of the Lens by Local Pressure from Tumors
OF THE Ciliary Body
Tumors (especially melanosarcomas or leukosarcomas) of the ciliary body extending in the direction of the lens may by local pressure cause deformation and indentation of the lens at the point of contact. Such an indentation may result in a compression of the outer softer cortical substance so that the distance between the outer bands of discontinuity (lines of disjunction and adult nuclear band) may be narrowed (Fig. 429 ) . In spite of the deformity no opacification in the compressed area may result. In one case of this type Vogt found a large water slit surrounded by vacuolar masses in the region of the lens between the posterior capsule and the posterior line of disjunction. Here, the local pressure resulted in a concave distortion of curvature within the lens so that the posterior band of disjunction was pushed toward the surface of the adult nucleus.^â€œ
BIOMICROSCOPY OF THE EYE
Spontaneous Dislocation of the Lens
Generally, spontaneous or nontraumatic dislocation of the lens follows some pre-existing ocular disease. Weakening (stretching)
Fig. 430. Dislocated lens (Marfans syndrome), a. Right eye. b. Left eye. (After Vogt.)
or disintegration of the zonule results in either a partial (subluxation) or complete (luxation) displacement of the lens. In the latter case (like a free balloon) it becomes completely detached from all its zonular and vitreous attachments and no longer occupies the fossa. In this case owing to the effects of gravity, it tends to sink. Depending on the fluidity of the vitreous and other local factors, the luxated lens may be confined to the vitreous, at times floating freely within it or depending on the size, width of the pupil, length of the zonular fibers, restraint of the vitreous and position of the head, it may wander back and forth from the vitreous to the anterior chamber. A sudden strain - from sneezing, coughing, or bending - may precipitate such displacement. Traction by inflammatory membranes may also lead to luxation of the lens. With tumors, and in cases of absolute glaucoma where the pupil is wide, a progressive subluxation of the lens may lead to complete luxation. Following luxation into the anterior chamber, the lens may at first remain clear, appearing like an â€œoil drop,â€ but as a rule it soon becomes opaque. Opacification of the cornea (edema, folds, etc.)
COMPLICATED CATARACT 1207
usually ensues. Cases have been I'eported in which ulceration of the cornea and extrusion of the lens occurred.
However, with subluxation in which the separation is incomplete, the unaffected parts of the zonule tend to pull the lens in a direction opposite to location of the torn or stretched zonular fibers. As a consequence of the eccentric position of the lens aphakia may result, provided the lens is sufficiently displaced from the pupillary area (Fig. 430). This may lead to a monocular diplopia where the vision in the affected e^^e occurs partly through the phakic portion of the pupil and partly through the aphakic portion. In subluxation the lens may be tilted forward, backward, or laterally and consequently may cause variation in depth of the anterior chamber, an effect that is easily recognizable with the biomicroscope. In rriost instances the free edge tilts toward the vitreous.
Disregarding the hereditary and congenital forms of lens displacement (e.g., ectopia lentis simplex - uncomplicated by other deformities - or complicated by other defects, especially Marfanâ€™s syndrome) spontaneous displacements are found, chiefly in high myopia, hydrophthalmia, hypermature cataract, and uveitis. *â€¢ In all of these the necessary requisites, i.e., zonular and vitreous degeneration, for freeing of the lens are present (Plate LXXVIII) . In hydrophthalmos, owing to distention of the globe, a breakdown or disintegration of the zonule may result in eventual luxation of the lens. In certain instances a breakdown of the capsule may occur and the contents of the lens may be extruded, the capsule remaining in situ, Jess saw such a case in the hydrophthalmic eye of a cat.
In contradistinction to the hereditary forms in which the subluxation is usually stationary, deterioration in the zonule and vitreous in cases caused by disease tends to be progressive so that ultimately total luxation of the lens may ensue.
From the standpoint of biomicroscopy, displacement of the lens pioduces a striking picture. As the focused beam passes through a subluxated lens in the vicinity of the displaced side (dilated pupil) ,
- Since the hereditary forms of dislocation of the lens are associated with defects in the zonule, they be considered in the chapter dealing with the zonule.
internal scattering of the light produces a bright reflex that outlines the equatorial rim of the lens (Fig. 459 A, p. 1344). In contrast to the bluish-gray relucency of the lens, the aphakic portion of the pupil appears jet black. In this aphakic area the focal beam revals the zonular fibers which may either be stretched or partially missing, but it is rare not to find some evidence of them. Frequently broken fragments of the zonule will be seen hanging from the capsule near the lens equator (Plate LXXVIII) . At times such fibers may be connected to a completely detached zonular lamella, which appears like a veil separated from the capsule. Several authors have reported cases in which the lens was luxated out of the enveloping zonular lamella (Jess,'^Â®Â® Meesmann and Stein . The tendency to opacification is greater in the luxated lens than in one that is only subluxated. But in either case an accompanying inflammation or increase in intra-ocular pressure will predispose to lenticular opacification, which is manifested as posterior complicated cataract, or subcapsular vacuolization commonly. In addition a form of zonular opacity that, like cataracta coronaris, outlines (in optic section) the curve of the adult nucleus at its equator may be found. The tendency for the opacification to become total is not unusual. In subluxation in spite of the apparent deficiency of zonular tension the biomicroscope will usually show the normal peripheral divergence of the anterior line of disjunction. This perhaps might indicate that the tension of the zonule only plays a part in the production of the phenomenon and that, as mentioned before, the major part of it results directly from the relative thinning and widening of the fibers axially where they abut the branching sutures.
Certain Pathologic Alterations of the Lens Capsule
Considering the importance of the lens capsule, very little is known concerning its origin, morphology, physical and chemical
The fact that the hyaline or cuticular capsule (probably formed as a secretion of the lens epithelium) was composed of numerous lamellae was established by earlier writers, such as Kolliker,Â®Â°Â® Ivanow and Arnold,^Â®â€™^ BergerÂ®Â°Â® and SchirmerÂ®Â®Â° and others. By maceration, Vogt found ten layers; the superficial (oldest) being the thickest. The deeper (towards the epithelium) gradually becoming thinner.
functions oiâ€˜ its exact role in the mechanism of accommodation. Likewise little is known about its physical properties, e.g., variations in elasticity during life. From histologic preparations it is known that the capsule thickens with age. This also is seen in cataract (especially in the hypermature and complicated forms) .
Lately our attention has been called to the importance of the capsule in the regulation and maintenance of lens metabolism. Considerable experimental work has been done on capsular permeability, in an effort to explain the exact role of this function in health and in disease. As it now stands we are confronted by a mass of controversial physical and chemical evidence that must await future clarification. Further, our interest in the capsulo-zonular diaphragm has increased with the modern trend toward intracapsular cataract surgery.
Clinically with the aid of the biomicroscope, the finding of certain other capsular changes (e.g., folds and exfoliation of the superficial lamellae) has substantiated many of the histologic observations. According to Vogt, four important clinical facts have been ascertained biomicroscopically: (i) Folding of the capsule - the formation of capsular folds is an early indication of shrinkage of the lens. This is seen in hypermature cataract and as a symptom of lens injury or traction by scars. The normal capsule produces fine delicate folds, those of the thickened capsule are coarse and sausage-like. (2) The normal capsule is always smooth, there being no such condition as a physiologic depression. An exception to this occurs in the presence of total sclerosis where localized irregular unevennesses in the capsule may occasionally be found. (3) The discovery of the detachment of the superficial layer of the capsule in glassblowers or those exposed to the action of heat (infrared cataract) . (4) The so-called "senileâ€ exfoliation of the superficial capsular lamellae, which may be attended by glaucoma (glaucoma capsulare) .
Under this heading are included anterior and posterior capsular changes, principally associated with inflammation and charac
BIOMICROSCOPY OF THE EYE
terized by tlie deposition of exudates and pigment and by the presence of vessels and linear structures (pleats). Genuine capsular folds are discussed on page 1140. It goes without saying that the above-mentioned capsular changes are also found secondary to inflammation induced by injury or operation. For the proper study of these capsular alterations dilatation of the pupil is usually necessary. In diffuse illumination, subcapsular changes, e.g., anterior complicated cataract (page iidi), might conceivably be confused with purely capsular alterations. With the focal beam, especially the optic section, the capsule stripe will become visible as a line and the above error can be avoided easily. Changes peculiar to the hyaline capsule will cause a change in direction (elevation or depression) of the first line of discontinuity (the capsule stripe) .
Other capsular alterations, such as the special changes (capsular and subcapsular) peculiar to the action of heat (infra-red), to contusions and perforating injuries (e.g., capsule ruptures, Vossiusâ€™ rings, siderosis and chalcosis, etc.) are considered elsewhere (Chapters 27 and 28) . The so-called â€œsenileâ€ exfoliation of the anterior lens capsule is also included in the chapter on pathologic changes of the capsule, rather than under the heading of a senile lens change. In spite of the fact that it rarely occurs before the sixth or seventh decade, its relationship to glaucoma and cataract would seem to warrant that it be considered as a pathologic entity rather than a purely senile physiologic change.
INFLAMMATORY DEPOSITS ON THE ANTERIOR LENS CAPSULE
Biomicroscopically, during or in the wake of intra-ocular inflammation, depositions on the anterior capsule in the form of exudates or pigment are a commonly observed occurrence (Fig. 431). In some instances, e.g., pigment stars and gray threads, it may at times be difficult from the standpoint of their morphology alone to distinguish between those resulting from inflammation and the physiologic rests of the tunica vasculosa lentis. As a rule in doubtful cases, careful consideration of the history and minute examination of the
BIOMICROSCOPY OF THE EYE
cornea, iris, and vitreous of both eyes for evidences of inflammation assist in making a differential diagnosis. However, it must be admitted that in cases of mild or ephemeral iritis, especially in the
Fig. 432. Inflammatory deposits on the anterior lens capsule.
absence of signs of synechiae, such a differentiation may be exceedingly diflScult.
Following iritis, the well-known deposits of irregular reddishbrown pigment occur on the capsule in the isolated form or in clumps or as a broken segmented ring outlining the place of contact of the pupillary edge and capsule; these become more evident on dilatation. When large they may be seen with the unaided eye. There may be fine pigment dust only, or large clumps may be surrounded b}'^ pigment dust. In addition to large clumps and amorphous grains, smaller circles of pigment may be found rarely occurring in cases of quiet iritis. With high power the surface of the larger pigment clumps will be observed frequently to have a finely granulated appearance. Also the deposits may be surrounded in places by a delicate grayish exudate, which possibly acts like a cement substance. At the site of a s^mechia such pigment masses may become stretched out, owing to pupillary action (see chapter on iritis). (Plate LXXIII.)
Exudate on the anterior lens capsule may assume various shapes and forms, the appearance of which frequently changes with time. When early and near the pupillary margin, it may resemble little dots, balls (efflorescences), or flat veils (Fig. 432). These can give rise to twisted threads which, when crossing one another, resemble loosely meshed nets or starHke figures. Upon these nets starlike
figures may be distributed. In some cases the pigmentation may be heavier and thus may hide the delicate grayish threads, so that only a layer of branching pigmented stars is seen. Pigment stars and threads may be arranged in irregular whorls or may extend themselves like a wreath (similar to Vossiusâ€™ ring) concentrically to the curve of the pupillary margin. Vogt noticed in certain cases that the direction of the threads tended to change as they approached the region of the the zonular attachment (equatorial areas). Here they lost their whorl-like aspect and radiated outward in a linear fashion. The nets and starlike figures may often surround an isolated larger pigment clump. Closely packed and condensed, the whole net may resemble moss. Unpigmented grayish delicate maplike designs may result which interrupt the shagreen of the capsule and display a faint color or iridescence. They are usually located peripherally, and maximum pupillary dilatation is essential. Occasionally more intensely white deposits are seen in the form of irregular rounded flat spots with crenated edges, separated from each other by clear areas. Peripheral radiating pigment lines, not unlike the retro-iridal lines described on page 1023, may be found. Larger more ephemeral radial streaks of pigment sparing the axial region are seen in acute or subacute iritis after pupillary dilatation. They are composed of fine pigment grains and have been known to become partially absorbed after a month or so. Like retro-iridal lines they may be derived from the pigmented ridges on the posterior surface of the iris, which possibly come in contact with the anterior lens capsule when the iris is swollen (Plate LXXIII, fig. i ) .
Another rare finding, described by Elschnig, is the presence of pleatlike formations on the capsule, visible only in the shagreen field. He considered them to be folds of the superficial lamellae of the lens capsule. Since true folds of the capsule can be seen outside of the shagreen fields, Vogt believes the pleats are formed by the separation and folding (?) of delicate extracapsular exudative membranes. (Fig. 431 C.)
Rarely, in association with synechiae, large ropelike or veil-like
Fig. I. Radiating pigment lines (resembling retro-iridal lines) and dots following inflammation (iridocyclitis) . Early anterior and posterior complicated cortical opacities. Diffuse illumination.
Fig. 2. Same case as shown in Figure i. Direct focal illumination. Optic section.
Fig. 3. Pigment stars and capsular exudate in iridocyclitis. Note elongated and stretched adhesion extending from capsular exudate to the pupillary border. Diffuse illumination.
Fig. 4. Same case as shown in Figure 3. Direct focal ilumination. Fligh power.
Fig. 5. Pigmented stars and exudate on the anterior lens capsule following inflammation.
Fig. 6. Fine netlike exudates and pigment on the anterior lens capsule after iritis.
COMPLICATED CATARACT 1217
membranes may occur; these tend to run concentric to the pupil. (Plate XLIX, fig. 4.) They may be connected to the lens capsule or to the pupillary edge. In the beginning such membranes may have been attached to the anterior lens capsule and later are partly or completely detached by the action of the pupil so that one end may remain attached to the pupillary edge of the iris while the other may float freely. In other cases one side or edge of the membrane may remain permanently attached to the capsule and the other to the iris margin. With pupillary contraction such membranes tend to fold, while with dilatation they stretch out.
Exudative membranes in the pupil, especially those attached to the lens capsule and adherent to the iris (e.g., after severe recurrent attacks of iritis or chronic iritis) , are frequently subject to vascularization. (Plate L, fig. 8.) Since the vessels do not meet severe resistance they arborize and loop freely in a manner not unlike the conjuncival or superficial corneal loops (in contrast to deep vascularization of the corneal stroma, where they are stubby and run in a direction parallel to one another). As in the cornea fine capillaries are best seen by retro-illumination. With this form of illumination their vascular anastomosing and looplike character is unmistakable. In the light reflected from the deeper parts of the lens, they appear faintly yellow. In direct focal illumination, reflexes arise, causing the appearance of an irregular maplike design on the capsule, which could easily be mistaken for surface irregularities in the membrane containing them. This is especially so when viewed in the shagreen fields. Larger vessels extending from the iris (in seclusion of the pupil) over an exudative pupillary membrane appear bright red by all forms of illumination and offer no diagnostic difficulties (Plate XLIX, fig. 7 and Plate L, fig. 8.)
INFLAMMATORY DEPOSITS ON THE POSTERIOR CAPSULE
In inflammatory states not only of the anterior ocular segment but also of the posterior segment as well, it is not uncommon to find precipitates (deposits, exudates and pigment) on the posterior capsule.
BIOMICROSCOPY OF THE EYE
Likewise such deposits are generally seen in "oldâ€ cases of retinal separation and occasionally in higher grades of myopia. Vogt found pigment deposits on the posterior lens capsule in a case of retinitis pigmentosa. Before the days of biomicroscopy the detection of such small deposits was not possible.
Precipitates on the posterior lens capsule correspond to the keratic precipitates found on the posterior corneal surface. It may be well here to emphasize that ordinarily the type of precipitates found on the posterior corneal surface and on the posterior surface of the lens are not seen on the surface of the iris or on the anterior capsule. However it has been pointed out that precipitates in the pupillary region of the anterior lens capsule may occur in sympathetic ophthalmia (Koeppe, Vogt and Meesmann) . It is claimed that in inflammation, deposits on the posterior capsule are not as frequent as those on the posterior corneal surface. This assumption, I believe, is due to the fact that during the acute phases, owing to corneal and anterior chamber haziness, this part of the lens is not so easily seen. Later, because of their ephemeral character they are sparser than those we are accustomed to find on the posterior corneal surface, but at the same time it is rare not to find some evidence of them. Another factor is that even in the beginning of an attack of iritis or cyclitis or during the quiet phases precipitates may be overlooked easily unless the posterior capsule is sharply focused with the narrow beam and higher powers of magnification employed. This is not always feasible. Needless to say, extensive opacification of the lens, e.g., cataracta complicata or nuclear cataract, may prevent or interfere with accurate observation of minute deposits on the posterior lens capsule. But in spite of such obstacles it is surprising at times how often it may be possible to visualize the posterior capsule with the sharpl)'^ focused beam. Despite the convex direction of curvature of the posterior lenticular surface, deposits are found predominantly in the lower parts of the capsule. The role played by convection currents in the anterior chamber in the distribution of keratic precipitates would of course have no bearing on the deposition of exu
COMPLICATED CATARACT 1219
dates on the posterior capsule. Here, one could only surmise that their location could be governed by eye movements and gravity. This does not mean that deposits are only found in the middle or
Fig. 433. Types of deposits on the posterior lens capsule, a. Disseminated, b. Perihyaloid.
c Annular, d. Inferior. (After Koby.)
lower parts of the capsule, for occasionally they may be seen in the upper regions as well (Fig. 415).
With the method of exact localization by means of optic section, deposits on the posterior lens capsule, although commonly associated with vitreous opacities, can be differentiated from them by the fact that the former are stationary, while the latter move with oscillations of the vitreous. Deposits on the posterior lens capsule may appear as small angular dots, delicate lines, larger flat disks, or as a fine whitish dust (Fig. 433) . Pigment is also seen as dustlike deposit either disseminated or in circular groups, or as clumps or bands 'Stretching over a considerable area. The pigment varies in color from yellow to reddish brown. Similar to the vitreous in late stages, it may not alwa^'^s be possible to differentiate uveal pigment from
BIOMICROSCOPY OF THE EYE
blood pigment (page 1450) . As in the case of deposits in the anterior chamber and vitreous, general rules cannot be laid down concerning the types of inflammation in which pigment deposits will predominate over white exudates or vice versa. They may of course be found coexistent, one or the other predominating. Probably, pigment dispersal is more likely to occur when the involvement is of such a nature as to cause swelling and breakdown of the cells containing it."' Pigment on the posterior capsule seems to occur with greater regularity when the iris is markedly involved and after retinal separation. It probably depends on the acuteness, intensity, and localization of the changes. Generally pigment deposits will be found after acute attacks of glaucoma, especially in those cases in which there has been surgical intervention, and in consequence the posterior capsule of the lens can be inspected more easily via the coloboma. In the so-called "quietâ€ cases of tuberculous iridocyclitis, it is not unusual to find whitish exudations on the posterior lens capsule and in the vitreous. Such small whitish spots, dust, or lines are not always ephemeral in character and rarely may be found even in the absence of corneal precipitates at the outset of the process as well as later. The importance of careful examination of the posterior lens capsule and anterior vitreous biomicroscopically in these cases is self-evident. In cases in which the deposit is large and disklike it is not rare to find bands of vitreous attached to it. Vogt described a case in which there was a large massive exudate with fine radiating white linear extensions in the region of the lental insertion of the hyaloid artery. The whitish exudate had vessels extending posteriorly to the disk. Nasally there were large pigmented belts on the posterior lens capsule extending from the periphery to the white exudate. An area of complicated cataract was adjacent to the white mass. Vogt attributed this to fetal inflammation in the region of the insertion of the hyaloid artery to the lens.
Kob)â€™" has pointed out that the topography of the deposit on the posterior lens capsule is determined by Cloquetâ€™s canal, the liga
Recently I saw a case of Retinitis Pigmentosa in which a complicated cataract was present at the posterior pole. There were numerous pigment deposits on the posterior lens capsule (see Plate LXXXI, fig. 5).
COMPLICATED CATARACT 1221
ment hyaloideo-capsulare of W^ieger,'* and at times by the insertions of the zonular fibers (zonular lamellae) . Accordingly, several types of distribution deposits on the posterior lens capsule can be differentiated: (i) disseminated or scattered form; ( 2 ) striaform; ( 3 ) grouped: (a) perihyaloid, i.e., about the hyaloid insertion, (b) inferior - localized in the lower regions, (c) circular - usually in the form of a peripheral arc (Fig. 433 ).
1)1556111111 ated Type. Depending on the severity of the inflammation the size of the deposits and their distribution varies. In some cases, the deposits may be spread uniformly over the posterior lens capsule as far as accessible to biomicroscopic examination. In others, the distribution may not be so regular, and the accumulations may be greater in the lower portions of the posterior lens surface. The character of the deposits varies chronologically. At the outset, small whitish dots may be discerned, later on in the course of the disease, transformation into stellate figures with processes may be seen. Sometimes by elongation of the processes a spider-web formation occurs. Both these forms may coexist. The tendency toward pigmentation is much less than in keratic precipitation. As in the case of keratic precipitates no inferences can be made concerning the etiology. However, the deposits in chorioretinitis are inclined to be smaller and more often pigmented than those seen in anterior uveitis.
The 5triaforin deposits on the posterior lens surface (Koby) have been principally seen following trauma - either contusions or perforation injuries. These striae are suggestive of those seen in the anterior chamber following injury (Vol. I, page 572 ). In both instances (i.e., anterior and posterior) fibrinous whitish striae may follow upon the posttraumatic hypotony. Such exudation may occur even in the absence of hemorrhage. They are characterized chiefly by their ephemeral nature, those in the anterior chamber clearing up within a matter of hours, while those on the posterior lens capsule resolve more slowly. Not having a double reflecting surface, they can be easily distinguished from folds of the posterior
It should be noted that this ligament is not demonstrable biomicroscopically. However anatomically a weak line of adherence of the vitreous to the posterior lens capsule has been demonstrated as a circular â€™zone 8 to 9 mm. in diameter about i mm. from the periphery.
BIOMICROSCOPY OF THE EYE
lens capsule. As a rule the striae on the posterior lens capsule are much smaller dimensionally than those in the anterior chamber. Koby describes their mossy appearance on the posterior lens capsule.
In the peri hyaloid type, clumping of deposits occurs within the concavity of the arcuate line around the insertion of the vestigial attachment of the hyaloid artery. Both Vogt and Koby have reported instances of yellowish granular or crystalline deposits in this area. These were associated with macular changes. In the first of Kobyâ€™s two cases the deposition followed a massive vitreous hemorrhage.
Such deposits may have to be differentiated from congenital or complicated lenticular opacities localized in this area. The optic section reveals the epicapsular location of the former as constrasted with the intralenticular position of the latter.
Inferior Type. One is more Hable to find this type following injury where hemorrhage has been sufficiently massive to allow the blood to gravitate inferiorly. In such cases one assumes that the erythrocytes infiltrated behind the posterior lens capsule within the hyaloid vitreous (Bergerâ€™s space), and were confined below by the annular attachments of the ligamentum hyaloidea-capsulare. Although inflammatory deposits can gravitate to the lower part, massive accumulations comparable to those occurring after hemorrhage have not been detected biomicroscopically.
Circular Form. Pigment deposits can occur in a circular form in inflammatory states either as a continuous or a broken line. Such circular deposits are usually located between the middle and external thirds of the capsular radius. Our chief interest with this form is mainly in high myopes where it may be associated with Krukenbergâ€™s corneal spindle. It is still a moot point whether such formations are congenital, postinflammatory, or degenerative. At any rate, cases are seen occasionally in which coexistence of a spindle-shaped pigmentation on the posterior corneal surface and an arc or ring of pigment deposited on the posterior capsule occurs. Because of the finding of pigmentation on the zonular fibers, Koby held that in these cases the annular shape of the pigment deposit is less influenced
COMPLICATED CATARACT 1223
by the ligamentum hyaloidea-capsulare than by the posterior part of the zonular apparatus (lamella and fibers). Hence the pigment would be contained in Hannoverâ€™s canal.
The pigment granules are yellowish or brown and very fine. Concentric annularly scattered grains may also be seen over other portions of the capsule and in the perihyaloid area as well.
EXFOLIATION OF THE LENS CAPSULE
Exfoliation of the superficial layers of the anterior capsule may occur in four conditions; (i) traumatic; (2) toxic (in atrophic eyes, after prolonged iridocyclitis or from the effects of a retained foreign body in the lens); (3) action of heat (infrared) (page 1295); and (4) senile (with or without glaucoma capsulare or cataract.
In this chapter only the so-called "senileâ€ exfoliation of the anterior lens capsule will be considered. According to Busacca (1927)Â®â€™Â® the lens capsule consists of three main divisions: (i) The overlying zonular lamella, derived from the terminal expansions of the zonular fibers. This occupies the equatorial portions of the capsule in an area 2 mm. wide thus comprising approximately onequarter of the total capsular surface. (2) A pericapsular membrane which covers the entire lens; and (3) the main part of the capsule which, as has already been pointed out, may be composed of several layers. Since in exfoliation of the lens capsule and in heat cataract the separation may occur in the pupillary part as well as peripherally, it follows that at least in the case of its more central location that the zonular lamella is not involved. Actual separation of the zonular lamella has been noted in other conditions with the biomicroscope by several authors (page 1208). In these cases a membrane detached from the equator was seen having zonular fibers inserted into it. In heat cataract the separated lamellae are many times thicker than in senile exfoliation. Consequently in the former the detached membrane is clear and lustrous and does not show the granular fragmentation and destruction so characteristic of senile exfoliation. In heat cataract, the thicker separated membrane ("fireâ€ lamella) hangs as a
Modified after Duke-Elder.
BIOMICROSCOPY OF THE EYE
continuous glasslike structure (comparable to that seen in separation of Descemetâ€™s membrane [Vol. I, fig. 203]), its sharp free edge tending to roll up in the anterior chamber axially. This free or floating curled edge (in the anterior chamber) is directed toward the periphery, whereas in senile exfoliation the detached edge is turned axialward. In heat cataract the axial part of the lamella is generall)^ adherent to the underlying and remaining hyaline capsule, causing an opacification. The separation from the capsule, the site of which is probably near the equator, is gradual and is not marked b) any sudden visible change. Another distinguishing feature of heat or fire cataract is the absence of the secondary glaucoma, frequently seen in senile exfoliation (glaucoma capsulare) .
The fact that a peeling or exfoliation of the superficial layers of the hyaline lens capsule does occur clinically confirms the anatomic finding in maceration preparations that this structure is laminated. This is especially noteworthy in those cases in which it has been seen biomicroscopically that in one place successive layers may become exfoliated. That is, after the most superficial layer is cast off, the layer beneath may likewise start to peel. Exfoliation of the superficial layers of the lens capsule (senile type) rarely occurs before the sixtieth year (however, a case occurring in a 41 -year-old woman was reported by Gradle and Sugar In 1917, Lindberg mentioned the finding of white flakes deposited on the pupillary border in glaucoma. In 1918 Vogt described the case of a 72-year-old man who later developed glaucoma. He mentioned the presence of a film on the anterior lens capsule, the edges of which were crinkled. Because of the presence of pupillary threads Vogt considered that the change was associated with residua of the pupillary membrane. Two years later he saw another case with chronic glaucoma, in which the film appeared as a faint limited capsular disk with crenated edges within the pupillary area. There were numerous bluish-white feltlike or crumblike deposits at the pupillary margin of the iris. Because this was found postoperatively he thought that they might be inflammatory products and stated that perhaps both structures, i.e., on the lens capsule and iris, consisted of the same substance. In
Fig. I. Senile exfoliation of the superficial lamella of the anterior lens capsule. Direct focal illumination. Note senile atrophy of the iris as viewed by retro-illumination. Exfoliated particles on the iris surface.
Fig. 2. Senile exfoliation of the superficial lamella of the anterior lens capsule. Case of glaucoma capsulare. Illustrating exfoliating dandruff-like particles some of which are attached to the pupillary margin of the iris.
Fig. 3. Senile exfoliation of the superficial lamella of the' anterior lens capsule. High-power view. Edges of exfoliated layers are curled back before breaking off.
Fig. 4. High power view showing details of exfoliating areas. Surface beneath exfoliating layer is beginning to desquamate.
1923, he came nearer the truth when, after finding the condition in cases of glaucoma that had not been operated on and were quiet, he postulated that both the capsular change (grayish disk with crinkled edges) and the deposits on the iris were not of inflammatory origin but resulted from an exfoliation of the superficial capsular lamella.This conclusion was strengthened not only by the physical appearance of the film (crinkling and eversion of its edges) but also because of the fact that exudative membranes do not tear off or crumble, no matter how thin they are; nor would they be only confined to the anterior capsule and be distributed in such a uniform way.
The exfoliated particles at the seam, or the iris surface or more rarely on the posterior corneal surface were never pigmented. There were no signs of iritis and the flakelike deposits themselves had none of the characteristics of inflammatory exudate. Hence, it was concluded that these grayish feltlike structures, especially characteristic for the pupillary seam or margin, are of the same nature as the material seen on the lens capsule but were deposited secondarily (Fig. 434) . It may be that the pigmented excrescences with their uneven and granular surfaces favor the adherence of the particles swept off from the anterior lens capsule by pupillary action.
The central disk in the pupillary area may be very faint and mayâ€ be easily overlooked. However, in most cases its periphery is outlined by a more opaque ring or edge of exfoliated material. Frequently the ring is seen, but the delicate film within it is missed unless the pupil is dilated. After this is done, one can compare the grayish color of the central disk with the adjoining area which, being film-free, is darker.
Dilatation of the pupil to a width of at least 4 mm. shows in nearly all cases a second phenomenon, i.e., the presence of a more opaque peripheral wreath of similar but more marked granular appearing structures or projections, arranged in a radiating fashion, located in an intermediary zone between the periphery and the central disk (See Plate LXXIV, figs, i, 2, 3, 4), The area between the disk and the more peripheral grayish deposits are clear, although
Failure to dilate the pupil and to employ the biomicroscope is probably the reason why many cases of capsule exfoliation are missed. This is understandable since from 50 per cent to 75 per cent of cases having this condition are associated with glaucoma.
BIOMICROSCOPY OF THE EYE
occasionally a few flakes may be deposited on it. The filmlike nature of the grayish material is best demonstrated at the edges, where exfoliation causes crinkling or even eversion. According to Vogt one gets the impression that there is a delicate membrane formed over the entire anterior surface of the lens and that at certain sites, i.e., where the posterior surface of the iris is in contact with the lens normally, this membrane seems to disappear either partially or completely. It should be recalled that the relief of the posterior pigmented iris surface is formed of radiating ridges (page 734). Where these ridges contact the lens capsule, they could either prevent the deposition on the capsule, or owing to sweeping movements, could keep this area clear of the exfoliated product. Iris movements, like a broom, could sweep away the granular degenerated products of the separated lamellae and leave clear areas behind. The absence of the possibility of such friction on the posterior capsule (if the condition does occur there) may account for the fact that granular accumulation on this part of the capsule has not been seen.
In contrast to the granular aspect of the film peripherally, the surface of the central pupillary disk is generally smooth. Except for the fact that its center (pupillary area) never contacts the iris, it is difficult to explain why this area does not become as granular as those in the periphery. However, the edges of the smooth central disk may show crumblike granules in which case a ring is formed. This may result from action of the pupillary margin which may "sweepâ€ up the particle in this region.
Another point to be considered in the formation of exfoliation is the action of the aqueous. Once a rupture has occurred in the superficial lamellae entrance of this fluid might cause further separation and degeneration. Repeated observation of an individual case will reveal not only changes in the arrangement but also even the disappearance (perhaps to the angle of the anterior chamber) of the exfoliated flakes, not only those of the lens capsule but also those on the iris seam. As mentioned before, successive layers of the capsule can come away, so that new exfoliated particles may appear as time
COMPLICATED CATARACT 1231
goes on. Following iridectomy the peripheral parts of the anterior capsule can be inspected.
It will be seen that the exfoliative changes decrease toward the equator. The radial extensions of the film become granular up to the region of the zonular insertion, where it (the film) tends to separate in a concentric manner. In the region of the zonular insertion, delicate whitish parallel lines (zonular fibers) can frequently be seen. As Vogt has shown, the detachment of the lamellae at this point is not fortuitous but could result from the traction of the zonule, the force of which would tend to tear the film or pellicle at right angles to its direction, or concentrically.
Another rather interesting finding in this condition was that of Vogt who on several occasions noted the sudden appearance of a cloud of pigment in the anterior chamber upon dilatation of the pupil with cocaine. None of these patients had diabetes but all had chronic simple glaucoma. The question arises whether this is related to separation of the superficial lamellae or whether it resulted from pigment changes known to occur in prolonged pilocarpine miosis (page 787) . However, he noticed it once in a case of glaucoma which was not complicated by senile exfoliation of the superficial lamellae and also once in a case (senile exfoliation and glaucoma) in which no miotics had been employed. In addition to resulting from a sudden bursting of iris pigment- containing cells, it might also occur from an accumulation of stored pigment in the posterior chamber. Dilatation of the pupil would permit the pigment to pass into the anterior chamber. Vogt found that following such dilatation a small cloud of pigment appears, sometimes tongue-shaped, in the anterior chamber in the region of the upper pupillary margin. In a few minutes it dispersed in the anterior chamber. In one case after half an hour there was only some fine dust to be seen. On further dilatation another cloud appeared and he found four small radial stripes of pigment on the anteiioi capsule. The second cloud was dispersed in a few minutes. The constant finding of pigment (and exfoliated particles) in the chamber angle gonioscopically (Barkan, Cradle and Sugar) in cases of exfoliation of the capsular lamellae might indicate that the sud
BIOMICROSCOPY OF THE EYE
den presence of pigment in the anterior chamber as described above is not surprising and that this phenomenon is probably considered rare only because few have observed it biomicroscopically. Considering the advanced age of most of the patients pigmentary degeneration of the iris is understandable. Cradle and Sugar (examining Terryâ€™s material) found serrations on the pigmented posterior surface of the iris characteristic of capsular exfoliation. According to Sugar (Vol. I, chap. 17) pigment granules deposited in the trabecular spaces are derived from the pigment epithelium of the iris which is traumatized by its constant movements against the roughened superficial capsular lamella. Irvine confirmed the finding of Trantas, Horven, Cradle and Sugar that exfoliative material is present on the zonule in iridectomized eyes. This raised the question whether the deposits were secondary, i.e., from the lens capsule, or whether a degeneration of the zonule per se also occurs (Irvine, and Cradle and Sugar) . Basing their contention on the possibility of a primary zonular disease, these writers also emphasized the commonly found vitreous changes (degeneration and fluidity), and suggested the idea that in exfoliation of the capsular lamellae we may be dealing with a syndrome involving many parts of the eye.
Considering that on the capsule the exfoliated material, principally, is not derived from the zonular lamella but from the superficial lamellae of the capsule axially to the insertion of the zonule, it would seem that the former supposition (i.e., that the deposits on the zonule, chamber angle, iris, and rarely the cornea are secondarily derived from the exfoliated material of the capsule) is true. Taking into consideration the age of the patients having this condition, I recently reexamined a case of capsular exfoliation in which there were no signs of glaucoma and compared her vitreous with that of another presumably normal elderly person of approximately the same age. Both showed the typical changes of the aged vitreous to about the same degree.
Glaucoma Capsulare. This term was coined by Vogt to designate the secondary glaucoma that so commonly occurs as a complication to exfohation of the capsular lamella. (See Vol. I, page 628). The
frequency of this association (probably close to 75 per cent) is demonstrated by Irvineâ€™s tables (see Tables XIX and XX) Originally both Lindberg ( 1917) and Vogt thought that the exfolia
PERCENTAGE OF PATIENTS WITH EXFOLIATION HAVING GLAUCOMA (AFTER IRVINE)
the litera Grzedzielski
the liter Baumgart
Holloway and Cowan
tion was a phenomenon secondary to simple chronic glaucoma. Later Vogt found many cases of exfoliation without glaucoma, and cases in which glaucoma developed during the period of observation, and he was forced to the conclusion that the glaucoma was secondary. According to Vogtâ€™s supposition (later substantiated by gonioscopic studies) particles of exfoliated material after a time become heaped up in the filtration angle, and eventually block it. He drew attention to the observation of Hess that large amounts of exfoliated capsular material (cuticular) would be material difficult to dissolve, digest.
BIOMICROSCOPY OF THE EYE
or absorb. The presence of exfoliated particles and pigment on the trabeculae was later confirmed gonioscopically by Barkan/^^ and Gradle and Sugar and histologicall)'- by Sobhy Bey (1932).'â€™^"
PERCENTAGE OF PATIENTS WITH CHRONIC SIMPLE GLAUCOMA HAVING EXFOLIATION (AFTER IRVINE)
â– c, Comment
Pupils not dilated
(not operated on)
(not operated on)
Pupils not systematically dilated
Pupils dilated in only 26 cases; percentage therefore low
Sugar also observed that in glaucoma capsulare peripheral synechiae are relatively absent. Horven/Â®' advanced the idea of â€œan altered permeabilityâ€ of the zonulocapsular diaphragm as the factor in the causation of glaucoma. Irvineâ€™s observations tend to confirm this view.
Cite this page: Hill, M.A. (2020, August 8) Embryology Book - Biomicroscopy of the eye 2-26. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_Biomicroscopy_of_the_eye_2-26
- © Dr Mark Hill 2020, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G