Accidental Injuries to Other Structures than the Lens during Couching.
Though the primary object of the Indian cataract coucher is to depress the lens, he may accidentally injure any or all of the other structures of the eye. Evidence of such damage is obtained both clinically and pathologically.
The Cornea.—Opaque scars on the cornea are quite frequently seen in the out-patient room in eyes which have been subjected to the anterior operation, but are rendered invisible in formalin-mounted specimens owing to the opacification of the membrane. Other evidence of corneal injury is, however, available.
In No. 9 a corneal fistula is present, lying to the inner side of the centre of the eye (Pl. IV., Fig. [23]). The lamellæ immediately surrounding it are largely replaced by connective tissue; the whole thickness of the membrane is markedly reduced, and the lining epithelium is irregular and vacuolated. The iris is very closely adherent to the back of the cornea near the fistula, but more loosely attached farther out. There has evidently been some ulceration of the cornea and the formation of a limited staphyloma, which burst at a later date, leaving the fistula now seen. It is probable that the point of fistulisation was determined by the use of a septic instrument at the time of operation, and that septic keratitis followed, leading to early perforation with entanglement of the iris. On the other hand, it is possible that the enclavement of the iris occurred as the instrument was withdrawn. In either case, the later sequence of events included a secondary rise in tension, the formation of a staphyloma, and a fresh perforation at the weakest point, resulting in the production of a permanent fistula.
In No. 45 the lens capsule is adherent to the back of the cornea, the iris being widely torn, and being probably also involved in the synechia (Pl. IV., Fig. [24]). All that remains of the lens is a brown nucleus; the cataract was evidently Morgagnian. It is probable that, after the escape of the fluid it contained, the lax capsule prolapsed into the wound, either with the gush of fluid which accompanied the withdrawal of the instrument or at a later date.
Fig. 22: Specimen No. 138.—A large Morgagnian cataract in its capsule lies dislocated behind the totally detached retina; the tear in the front part of the lower half of the retina, through which the lens was thrust, is now represented by a wide puckered scar.
Fig. 23: Specimen No. 9.—A whole-section showing a persistent fistula of the cornea.
Fig. 24: Specimen No. 45.—A brown nucleus dislocated downward in its capsule lies tightly adherent to the back of the iris and ciliary body; it is fixed there by organised exudate, the bands from which radiate out into the retina and are determining the detachment of that membrane. The iris is torn on the nasal side, and through the tear there passes a capsulo-corneal synechia.
Fig. 25: Specimen No. 116.—The retina is totally detached, and rolled up like a closed umbrella. There is a retino-corneal synechia. The lens has been reclined; it probably lay outside the vitreous cavity. The subretinal exudate, coagulated by preparation, gives the eyeball the appearance of a cut marble. During life the pressure of the lens, which had been wedged backward, thrust the retina and the parts adherent to it backward below, thus displacing the subretinal exudate there, and causing it to bulge in the upper half of the eyeball; this bulge effectually obliterated the upper part of the anterior chamber, whilst the direct pressure of the lens obliterated the chamber below.
Fig. 26: Specimen No. 306.—There is a pigmented scar running through the thickness of the sclera, just behind the level of the ciliary processes. The optic disc is deeply cupped, and the anterior chamber is very shallow.
Fig. 27: Specimen No. 306.—Low-power magnification of the previous specimen shows a persistent fistula running through the substance of the sclera; the ciliary body is impacted in its deeper part, and there is a filtering scar on its surface.
PLATE IV.
Fig. 22 (No. 138).—Right eye, lower half.
Fig. 23 (No. 9).—Left eye, whole section.
Fig. 24 (No. 45).—Right eye, lower half.
Fig. 25 (No. 116).—Right eye, nasal half.
Fig. 26 (No. 306).—Left eye, upper half.
Fig. 27 (No. 306).—Microscopic section, low power.
In No. 116 it is the retina which is impacted in the corneal wound (Pl. IV., Fig. [25]). It seems likely that in this instance the sequence of events was as follows: A severe plastic inflammation resulted from the couching, and involved among other structures a capsular synechia, which had formed at the time of operation or soon after. The vitreous became heavily infected, and the consequent exudate became adherent on the one hand to the retina, which thereby underwent total detachment, and on the other to the capsule and its synechia. The progressive contraction of the scar-tissue then drew the retina into the wound. This would appear to be the most likely explanation, but it is not impossible, in dealing with such an operation as couching, that the retinal detachment was very extensive, and that the injury inflicted provided a path along which a direct prolapse of the retina may have occurred.
The Sclera.—A very large number of Indian cataract couchers perform the posterior operation, and therefore make their preliminary incision in the sclera outside the limbus. Dr. Ekambaram, who has watched these men at work, believes that they deliberately endeavour to avoid the ciliary body, and it also looks as if some of them purposely place their incision below the external rectus muscle. Like his Western confrère, the Indian surgeon does not always succeed in placing his incision just where he wishes to; this is not surprising, as many of these men work without any local anæsthetic, and not a few of their patients are nervous and unruly to the last degree. Moreover, it is more than probable that there are different opinions amongst couchers as to the best site for the preliminary cut. These considerations will serve to explain the variety of location of the scars, as found in the specimens before us; indeed, some such explanation is called for, since the cicatrices may be found as far forward as the limbus, and as far back as the equator of the globe; what is more, they may be seen in the present collection, not only in their common situation, on or near the horizontal meridian, but in any of the quadrants of the eye.
As a rule, the evidence of injury to the sclera is to be inferred from the interference with the parts beneath that coat, and such instances will be taken up when we come to consider the lesions of the ciliary body and choroid; but occasionally we have been fortunate enough to hit off the scleral scar either in the original division of the globe or during the course of sectioning of part of it for the purpose of microscopic examination.
In No. 306 the track of the original wound can be seen as a pigmented scar in the sclera immediately behind the line of the ciliary processes (Pl. IV., Fig. [26]). Microscopic sections show—(1) that the pigmentation of the deeper part of the scar is due to the impaction of uveal tissue in its depth; (2) that there is a fistulous scar running right through the thickness of the sclera; and (3) that the subconjunctival tissue in the neighbourhood of the wound is permeated by large open spaces lined with endothelium (Pl. IV., Fig. [27]). It is clear that a limited measure of filtration had been established, but this apparently proved insufficient to keep the tension of the eye from rising, as is shown by the deep glaucomatous cupping and by the obliteration of the anterior chamber.
No. 43 shows a scar a little farther back, in the neighbourhood of the ora serrata; but in this case the wound appears to have healed solidly. The pigment of the underlying uveal tissue shows a marked disturbance, whilst before the specimen was cut it was observed that the sclera was pigmented in the neighbourhood of the cicatrix.
In No. 8 the wound lay in the limbus, and the solidifying scar can be traced right through the thickness of the ocular tunic and down to the mass of inflammatory exudate which surrounds the dislocated lens, and fills the angle of the anterior chamber. Here, again, the pigment can be traced some distance up into the scar, in which the uveal tissue is distinctly entangled.
The Uveal Tract.—In quite a large number of couched eyes one can see, during life, evidence of past injury to the iris in the form of more or less extensive scars, many of which probably also involve the ciliary body. Moreover, in other cases, one can infer the presence of injury to the ciliary body and the choroid from the existence of pigmented cicatrices in the sclera. Anatomically, the present series of eyeballs affords additional information on this head. Iris scars are fairly common. In one case, already referred to, the coucher had effected a cyclodialysis; in 3 more the wounds lie across the front parts of the ciliary processes; in 6 they involved the region of the orbiculus ciliaris, and in one of these the scar lies as much on the choroid as it does on the ciliary body (Pl. II., Fig. [15]); lastly, in 4 the wounds lie well behind the ciliary body, being placed in 2 of them just in front of the equator, and in 2 more well behind it. Taking them as a whole, the wounds tend to be grouped in the outer quadrant of the eye, above or below the horizontal meridian. It has already been pointed out that this is in accordance with Ekambaram’s evidence as to the site of selection for the incision in the posterior operation. Far the best method of examining these scars is by transillumination with a bright light from behind. Some points of interest remain for consideration.
In No. 44 the wound lay behind the ciliary processes (Pl. II., Fig. [11]), the instrument, most probably at its point, tore off a tongue-shaped process from the posterior surface of the iris, thus thinning that membrane over this area; the torn portion contracted an adhesion to the subjacent hyaloid membrane, which was itself infiltrated with inflammatory exudate; the appearance presented is curious and interesting.
In several of the globes scar-tissue radiates from the wound area into the surrounding tissues, and is then a strong contributory factor in the production of retinal detachment. In one globe (No. 130) two scars are to be seen, one of which was evidently placed too far back by mistake (Pl. V., Fig. [28]); the eye also furnishes contributory evidence that things did not go well during the operation, for the iris is very widely lacerated. It seems probable that the patient was refractory or the surgeon unskilful. In any case, it is clear that the instrument was introduced a second time.
In No. 148 a caseating mass in the eyeball (Pl. V., Fig. [29]), lying behind the equator, was found to contain a fragment of metal; the latter was most unfortunately lost at the time the section was cut, but it was presumably the tip of the couching instrument, and its presence, taken with the facts that the wound was placed very far back and that dislocation of the lens was not effected by the operation, would seem to indicate that the patient moved violently and that the operator failed in his purpose. The strong but strictly localised inflammation excited suggests that the metallic fragment was of copper, and this is in accordance with the known facts of the case, since the probes used by these men to displace the lens are made of that metal.
No. 72 is also a specimen of special interest. Here, too, the puncture lay behind the equator, and there seems to have been some difficulty in penetrating the choroidal and retinal coats, which were carried in front of the instrument, the result being a wide separation of these two tunics from their scleral bed (Pl. V., Fig. [30]).
No. 297, removed six weeks after the operation, is an eyeball which had undergone panophthalmitis, and had burst through a point in the sclera on the horizontal meridian somewhere in front of the equator. It is probable that a septic wound of entrance determined the site of the bursting. The lecturer has seen suppurating globes in which the sclera at one point had completely sloughed, the intense inflammation present bearing witness to the violence of the infective process excited.
Uveitis.—The type of inflammation of the uvea found in these specimens was plastic, and was mostly confined to the iris and ciliary body. The intensity of the inflammation varied very greatly. In a number of specimens the evidence of inflammatory action was either absent or only to be detected on very careful examination. On the other hand, a large number of cases present themselves at Indian hospitals in which suppurative panophthalmitis has followed the operation of couching. In Madras such globes were eviscerated, as it was considered dangerous to enucleate them, and much interesting material has thus been lost. All the intermediate stages between the very slight and the very severe inflammations can be traced in the specimens before us. This is in accordance with what we should have expected in what was practically a series of inoculations of healthy globes with pathological materials, which varied enormously in their nature and in the quantity introduced. Nor must we forget the great differences in the ages and in the conditions of health of the patients. The plastic mass poured out from the ciliary body and iris had in many cases enveloped the remains of the lenses (Pl. V., Fig. [31]; also Pl. III., Fig. [19]), which can be seen in process of disintegration under the action of phagocytosis (Pl. V., Figs. [32] and 33) or of fluid absorption. Evidence of calcification of the lens was obtained in at least one specimen (Pl. VI., Fig. [35]), and the same process was also found at work in the uveal coat of several others. The rupture of the lens capsule often provides a ready path of ingress for the inflammatory exudate, which can then be seen filling the cavity of the capsule as well as surrounding it. The curly remains, both of the anterior and of the posterior portions of the capsule, can be clearly traced in many of the specimens, imbedded in dense masses of organising inflammatory exudate. In several such, the absence of the capsule opposite or to one side of the pupillary area, and the curled-up ends of the elastic membrane, mark the spot where rupture was effected at the time of operation.
Fig. 28: Specimen No. 130.—The iris shows a deep jagged tear. There are two scars made at the operation, one over the posterior part of the ciliary body, the other near the equator of the eye. Numerous white dots are seen on the choroid and iris.
Fig. 29: Specimen No. 148.—There is a localised patch of inflammation within the globe behind the equator; in this was found a foreign body, probably the tip of the copper probe used in the operation. It lay in the vitreous cavity within the retina, which is totally detached.
Fig. 30: Specimen No. 72.—The operation scar can be seen on the temporal side of the sclera behind the equator. The choroid and retina are extensively detached on this side, having evidently been pushed before the instrument before it succeeded in penetrating them. To the nasal side in the anterior part of the vitreous chamber lies a cone of exudate, the apex of which (posteriorly) is adherent to the retina, and has raised it from its bed in the form of a shallow bleb. The cornea fell in during preparation; it was ulcerated. The anterior chamber was full of pus and blood. What is left of the lens lies buried at the base of the cone of exudate already referred to, being bound thereby to the ciliary body and to the back of the iris.
Fig. 31: Specimen No. 171.—A whole-section of the eye shown in Fig. [19]. For details of description refer to that figure.
Fig. 32: Specimen No. 171.—Low-power magnification of a portion of the specimen shown in the previous figure. To the right is seen the inflamed and matted iris; beneath this lies a mass of inflammatory exudate in which the curled remains of the lens capsule can be traced. In this mass of exudate the lens nucleus lies imbedded, its margins being surrounded by large phagocytes.
Fig. 33: Specimen No. 171.—High-power magnification of portion of the previous specimen, showing some of the phagocytes much enlarged. Notice their processes invading the lens substance.
PLATE V.
Fig. 28 (No. 130).—Left eye, upper half.
Fig. 29 (No. 148).—Left eye, upper half.
Fig. 30 (No. 72).—Right eye, lower half.
Fig. 31 (No. 171).—Left eye, whole section.
Fig. 32 (No. 171).—Microscopic section, low power.
Fig. 33 (No. 171).—Microscopic section, high power.
In only one instance has any evidence of proliferative uveitis come to light, and in this one the nodule in the iris consists of mononuclear lymphocytes; epithelioid and giant cells are conspicuous by their absence. The interest of this observation centres in the fact that a large number of these globes were removed with the object of guarding against the occurrence of sympathetic ophthalmia, or of making safer the performance of an extraction in the opposite eye. So far as the first indication is concerned, it would appear that the danger of sympathetic mischief in the second eye after couching is not great. The deduction thus drawn from pathological data is confirmed by the author’s clinical experience, for, as far as his observations go, it is extremely rare to see the second eye lost by sympathetic ophthalmia after this operation.