CHAPTER XI Tue Lens (Part 2)

not suffered from ophthalmia neonatorum, the perforation of a corneal ulcer, iritis, or trau- matism. The degree of vision depends not only on the size of the opacity, but also on the thinness of its center, which sometimes is almost diaphanous. We must ascertain how much it can be improved by glasses, when the patient is old enough to be tested, and whether it can be helped by dilatation of the pupil, before we decide con- cerning whether any treatment should be given, as it is exceptional for any changes to occur in the extent or the density of the opacity after this time, though probably changes do take place during the very early years of life. Occasionally we need to differentiate a zonular from a mem- branous, or a siliquose cataract, and we do this by observing the conditions of the anterior chamber, iris, and pupil. In an un- complicated case of zonular cataract the depth of the anterior chamber is normal, the iris is not tremulous, the pupil is round, free, and active, while in both of the others the chamber is deep, the iris is tremulous, and often is adherent to a secondary membranous cataract so that the pupil is irregular and hampered in its movements. Total Cataract Another rather common variety of congenital cataract is the total, in which both lenses are completely opaque. They are uni- formly white and the diagnosis is easy. It is sometimes difficult to tell whether they are advanced zonular cataracts, or were caused by vascular trouble in the embryo, perhaps by a perivasculitis of the vascular capsule; but in most cases this is not a matter of vital importance. Central Cataract Occasionally we find a round, white dot in the center of the nucleus, which affects vision very little and is not accustomed to THE LENS 255 progress. Such a central cataract may be present in both eyes, perhaps in association with other opacities, or we may find it in one eye and some other form of congenital cataract in the other. This form is always congenital, is hereditary, and bears no resem- blance to the nuclear variety of senile cataract, which appears in advanced life as a cloudiness of the nucleus. Fusiform or Spindle Cataract Once in a great while we see lenses in which a tubular or spindle- shaped opacity extends from the anterior to the posterior pole of the lens, or from the former to the nucleus. Such an opacity is always congenital, whether it is accompanied by others or not, and is not to be mistaken for anything else. Posterior Polar Cataract Sometimes we are able to detect an opacity, frequently no larger than a pinhead, at the posterior pole of the lens. The only subjective symptom that can be considered at all characteristic is a speck to the outer side of the patient’s line of vision which is constant, but continually eludes his attempts to fix upon it. What we see is a gray spot situated deeply in the lens, which we ascertain to be behind the nodal point through its parallactic displacement in the direction opposite to that in which the eye is moved, but it is not always easy to demonstrate whether it is due to a change in the pos- terior capsule, or in the posterior fibers of the lens. If it happens to be associated with some other form of congenital cataract, pos- terior lenticonus, or remains of the hyaloid artery, we feel pretty sure that it is congenital, but if none of these things are present we examine the fundus in search of pigmentary degeneration of the retina, or choroiditis, both of which may induce the defect through the formation of an opaque spot at the posterior pole of the lens, probably as the result of a disorganization of the vitreous. This spot may show some radiating lines when it is caused by pigmentary degeneration of the retina, but it has no tendency to advance into the lens; while in choroiditis it is apt to be stellate and progressive, involving the posterior cortex after a while, and sometimes the an- terior as well. When neither of these diseases can be found we have to remember that a similar opacity has been said to result from traumatism, and to be at times symptomatic of uric acid poisoning. 256 DIAGNOSIS FROM OCULAR SYMPTOMS Anterior Polar Cataract A small white spot is to be seen quite often at the anterior pole of the lens, perhaps so small as to be scarcely perceptible, or so large as to occupy a great part of the pupillary space. The effect on the vision varies from almost nothing to serious impairment, but a person with a large anterior polar cataract in each eye cannot see as well in bright daylight, when the pupils are contracted, as he can in the evening, when his pupils are larger. When the opacities are flat, more or less stellate, flush with the capsule, the cornee are normal, and the defect is present in both eyes, the condition may be pronounced congenital, and generally it is hereditary in these cases. Much more commonly the trouble is acquired, and we are able to obtain a history of a severe inflamma- tion of the eyes. It certainly is acquired if, instead of being flat, it projects into the anterior chamber and forms a pyramidal cataract, or if a thread of connective tissue floats out from it, or joins it to the cornea, which happens in rare cases. When it is flat we ex- amine the cornea carefully for a cicatrix, which may be hard to find even when it was made by a deep or perforating ulcer, as cicatrices sometimes clear up almost perfectly in children. As a rule the ulcer was central and perforated the cornea, but rare cases have been met with in which an anterior polar cataract resulted from an ulcer that perforated in the more peripheral part of the cornea, or did not perforate at all. The history and signs of a past iritis may suggest this as the cause. When the defect is unilateral the chances are strongly in favor of its having been acquired. Punctate Cataract If we look closely enough we occasionally find minute, bluish gray points scattered about in the anterior and posterior cortex, or ar- ranged in a stellate manner about the poles. If the patient is a child these points are of little importance, as they rarely change and are supposed to be congenital, but in adults they have been ob- served to be the first indications of an incipient senile cataract. We do not know whether the congenital punctate spots finally prove to be centers from which a senile cataract may develop, or whether similar spots appear later in life as foci of changes in the lens. THE LENS 257 Degenerated Cataract ‘Sometimes we meet with a child in whose eyes the anterior cham- bers are deep, the irides tremulous, the lenses cataractous and shrunken, possibly ectopic. A large part if not all of the lenticular fibers have broken down into fluid, more or less of which has been absorbed, while earthy salts may have been deposited in the lens or its capsule.. The cataracts appear flat and chalky white in most cases. Sometimes they are called milky, sometimes calcareous. They resemble the Morgagnian, or hypermature senile cataracts, but are differentiated readily, not only by the age of the patient, and the history, but by their appearance. They are formed either before birth, or from congenital cataracts, while the Morgagnian is always preceded by the development of a senile cataract, and contains a hard nucleus which frequently may be seen to form a dark spot as it strikes against the anterior capsule during move- ments of the eye. Sometimes the fluid has disappeared so com- pletely that the anterior and posterior capsules come nearly or quite into contact so as to form little more than a membrane; this is called aridosiliquose cataract if lime salts have been deposited, otherwise it often is called membranous, but the suggestion of Beard is good that it is better called siliquose, to distinguish it from the secondary membranous cataract which frequently follows an ex- tracticn. A siliquose cataract may be the final stage of a total or a zonular, or it may be due to either an intrauterine inflammation, or an intrauterine rupture of the capsule followed by absorption of its contents. Beard describes as a cystic cataract an extremely rare form in which decomposition has occurred, so that the mass within the cap- sule has been rendered putrid. He says that such a cataract has something of the appearance of a deflated balloon, a part of which projects into the anterior chamber, and generally is of a yellow color. The protrusion is apt to be greater below than above, and may oscillate slightly with the movements of the head. Traumatic Cataract When an opacity appears in a lens soon after a known traumatism the diagnosis of traumatic cataract is easy, especially when it has developed under observation. As a rule it progresses rather rapidly 258 DIAGNOSIS FROM OCULAR SYMPTOMS until the entire lens has become involved, but occasionally its prog- ress is so slow that months, perhaps years, may elapse before the patient notices that his vision is impaired. The fact has been es- tablished both clinically and experimentally that a cataract may de- velop long after a contusion, or a dislocation of the lens, and yet be dependent on the injury. This is an important medicolegal point, and we need to know when we shall be justified in pro- nouncing a cataract traumatic if the history of the case is unknown or questionable. A traumatic cataract may be caused directly by a wound of the lens, or indirectly by a contusion of the eye, a concussion of the head or body, or by an electric shock. We know that cataract can be produced by electric flashes, the X-rays, and the conditions under which glassblowers work, and it is a question whether these should be classed as traumatic or not, for we do not understand exactly how they are produced, but certainly they may be referred to ex- ternal influences. The symptoms vary with the cause, the interval of time that has elapsed since the injury, and the age of the patient. If the lens has been wounded recently we shall almost surely find a conjunc- tival and a ciliary injection, a hyperemia or an inflammation of the iris, together with whatever lesions may have been produced in other tissues by the injury. The lens itself may be in its normal position, or it may be dislocated. Probably we find it swollen and occupied by a grayish white mass, part of which may protrude from a rent in its capsule. Sometimes the patient is in great pain from secondary glaucoma. If the lenticular mass is yellow, suppuration is present. In other cases the wound in the capsule is small, there is little if any protruding lens matter, and more or less of the lens may be clear. In very rare cases a comparatively small opacity may be left per- manently, but, as a rule, the entire lens becomes opaque sooner or later. In a child the lenticular fibers usually break down and are ab- sorbed, so that at the end of a few weeks or months nothing may be left of the lens except the capsules, which have come together to form a siliquose cataract. Sometimes the wound closes before this end is attained and then we find a soft, milky looking cataract. Complete absorption cannot be expected in an adult, although it is observed occasionally even in advanced life, because the firm nucleus ordinarily refuses to disintegrate. The older the patient the more THE LENS 259 slowly do the changes take place, but whatever his age may be a wounded lens usually becomes completely opaque. Once in a while we see a case in which a localized opacity remains stationary, ex- tends slowly, or clears up more or less if the patient is very for- tunate. Such cases are exceptional and are more common among adults than among children. Only one eye is affected as a rule in these cases, but both may suffer in some accidents, like explosions. A cataract may develop at any age as the result of a contusion of the eye, whether the lens is dislocated or not. If a total or partial cataract forms in an eye known to have received a blow, we have good reason to pronounce it traumatic, but should this diagnosis be questioned we may need proof. If the eye is known to have had good vision prior to the accident there is no question as to the correctness of the diagnosis, but we cannot always obtain this evidence. In a young person we need to exclude cataract that is congenital, or has been caused either by disease, or by a nontraumatic inflamma- tion of the cornea. If the cataract is total, whitish and stellate in appearance, and the tension of the eye is normal, or perhaps slightly plus, while the other eye is normal in every respect, both the con- genital form and that due to disease are excluded with a high degree of probability, because congenital total cataracts almost invariably are bilateral, or associated with defects in the other eye; while the absence of minus tension and of a past severe iritis exclude iridocy- clitis as a cause, the absence of high tension and of the peculiar ap- pearance of a glaucomatous cataract exclude glaucoma, and other diseases of the eye seldom if ever cause a total cataract. Such a very rare condition as a unilateral diabetic cataract can be excluded by an examination of the urine for sugar. If the cataract is partial and about the posterior pole we must exclude the presence of re- mains of the hyaloid artery and of posterior lenticonous, as well as of choroiditis, pigmentary degeneration of the retina, and the uric acid diathesis before we can positively pronounce it traumatic, but these congenital and morbid conditions are almost invariably bilateral. If the opacity is zonular in type and the other eye normal, the question is one of probability between two extremely rare conditions. An imprint of the pupil on the anterior capsule furnishes positive proof of a traumatism. A flat, unilateral anterior polar cataract probably was caused by the perforation of a corneal ulcer, just pos- sibly by an iridocyclitis, but while it would be going too far to say 260 DIAGNOSIS FROM OCULAR SYMPTOMS that it could not be produced by traumatism, yet the history of in- jury would have to be very distinct as prior to its appearance, and all other causes would have to be excluded before we could say that it was traumatic. It very rarely happens that a person is stung in the cornea by a bee, but such an accident accounts perfectly for the formation of a traumatic anterior polar cataract. Soon after the bee has stung the cornea an opacity appears in the anterior layer of the cortex of the lens in the region of the pupil, and clears up to a great extent in a few days, but usually leaves a permanent central spot. ‘This result seems to be due to a toxic action, rather than to the traumatism itself, as it has been proved experimentally that the sting must pass through the cornea and inoculate the aqueous with its poison. The difficulty of diagnosis is much greater when a cataract de- velops in an elderly person some time after a contusion, because it is hard to exclude a possible coincidental development of a senile cataract, even when it is watched from the first. This is shown by the following case. A man sixty years old was struck in the eye by a piece of wood that caused a contusion with abrasion of the skin and cornea. The pupil was dilated with a mydriatic and the lens found to be perfectly clear. Two days later converging opacities were to be seen in the upper inner periphery of the lens. An in- cipient cataract was evident a month later, though the vision was 20/20. The cataract progressed steadily, resembling at all times and in every*respect the ordinary senile variety, while the vision fell to 20/50 at the end of three months, and to counting fingers at the end of six months. I believe this to have been a traumatic cataract because I watched its development and know the contusion to have been an adequate cause, but the possibility of a senile cataract which started just at that time independently of the injury cannot be ex- cluded. We can only say that such a coincidence would be remark- able, and that the development of a cataract which showed its first traces in a previously perfect lens within a short time after the oc- currence of an adequate injury justifies us in calling it traumatic. This case also illustrates the fact that considerable time may elapse after the receipt of a contusion before the patient notices any trouble, even when changes in the lens begin almost immediately, for the vision was 20/20 at the end of a month, and 20/50 after the lapse of three, and even a loss as great as the last often is insufficient to attract an elderly patient’s attention. THE LENS 261 A person may fall from a height and strike on his feet, or on some part of his body, may be badly shaken up, as in a railroad accident, or may receive a blow on the head, all with no contusion of the eye, and yet one or both lenses be rendered cataractous. The same thing happens sometimes after an electric shock, when the current is sup- posed to have passed through the eyes. There is