The Indian operation of couching for cataract

by Robert Henry Elliot

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.