From a consideration of the lenses found floating in the vitreous, we turn to that of those which were entangled in a more or less consistent inflammatory exudate occupying the vitreous chamber (Pl. II., Fig. [15]). During life such lenses were reported to be fixed, or nearly so. In the specimens they are seen to be nested in a mass of exudate, which holds them imprisoned against the ciliary body and the back of the iris. Usually this exudate is limited in quantity and is confined to the anterior portion of the eye, and principally to the neighbourhood of the dislocated lens. More rarely it is very abundant, and occupies a large part or even the whole of the vitreous chamber (Pl. III., Fig. [16]). We shall deal with this exudate more fully at a later stage; for the present it suffices to state that it is inflammatory in origin, and that it contains a large number of cells. Of the 6 cases which form this group, 3 were Morgagnian cataracts; 5 were certainly dislocated in their capsule, the sixth is hidden in such dense exudate that it cannot be clearly seen. It is desirable to make it clear that intermediate forms are found between this group and the previous one. In other words, there is no hard-and-fast line between the cases in which the lenses float freely in the vitreous and those in which they are, to a greater or less degree, tethered by the pathological thickening of the hyaloid body.
We have next to consider a group of 10 eyeballs, in each of which the dislocated cataract was firmly fixed to the ciliary body and to the back of the iris by definitely organised fibrous tissue (Pl. III., Fig. [17]). These globes present certain well-marked features of some interest: (1) The percentage of Morgagnian cataract is much lower than that in the preceding groups, and corresponds closely with the normal frequency of this form of cataract in Indian practice. (2) The cataract was dislocated in its capsule in no less than 8 of the 10 cases. (3) The retina was totally detached in 2 and very extensively so in one; in every one of the remaining 7 this membrane showed the presence of white dots, apparently on its surface. (4) The time which had elapsed since operation in the cases falling under this group is remarkable. In one it is given as seven months; in 2 others there is no history; in the remaining 7 the duration was from two to twenty years, with an average of well over seven years. The association of the presence of white dots with these long histories is remarkable, and will be taken up in a later section.
No. 99 (Pl. III., Fig. [18]) is a specimen of special interest for two reasons—viz., (1) the cataract is fixed to the globe unusually far back, being attached to the retina a little behind the equator of the eye; (2) the dislocation has taken place in an upward direction, and therefore against the action of gravity. From time to time we meet clinically with a couched lens whose suspensory ligament, though torn through over a wide circumference, has been spared at one part, which acts as a hinge. The loosened lens flaps backwards and forwards with the movements of the eye, at times obstructing the pupil, and at others being lost to sight. If the hinge is above, the cataract usually blocks the pupil when the head is erect; but one meets with cases in which the lens floats up out of the way unless the face is thrown forward into the horizontal plane; this is apparently due to a check-ligament action of the remaining suspensory fibres of the lens, acting on a lens which is very nearly of the same specific gravity as the vitreous in which it lies. Should inflammation be set up in such an eye and the lens become involved in the exudate, it may become fixed, as in this case, in the upper segment of the globe.
Fig. 16: Specimen No. 197.—The exudate into the vitreous cavity is abundant and opaque, concealing the dislocated cataract. (Time since operation, one month.)
Fig. 17: Specimen No. 37.—The lens is tied to the back of the iris and ciliary body by firm organised exudate, which is continuous with and part of the cone of inflammatory material representing the shrunken vitreous. Notice the advanced organisation evident in the apex of the cone near the optic nerve, also the white line apparently representing the hyaloid canal. Some large dots and many small ones are to be seen on the retina.
Fig. 18: Specimen No. 99.—A large lens in its capsule is dislocated upward and inward, and is adherent to the retina by inflammatory bands. The retina shows very numerous white dots. There is a tendency to equatorial scleral staphyloma.
Fig. 19: Specimen No. 171.—The retina is totally detached and rolled up tight; cysts both false and true are to be seen in it. The lens is imbedded in a mass of inflammatory exudate, matted to the iris and ciliary body in front, and to the retina behind; the ciliary body is detached. The coagulated subretinal exudate gives the specimen the appearance of a half-marble. The sclera is folded owing to the shrinking of the eyeball.
Fig. 20: Specimen No. 119.—From before backwards can be seen the iris, the remains of the lens capsule, and the thickened anterior layer of the hyaloid. The lens is dislocated backward between the second and third of these, and is wedging them apart. The retina is detached over nearly half the globe; this is in large part determined by the pull of the shrinking thickened anterior hyaloid layer.
Fig. 21: Specimen No. 46.—The hard dark nuclear cataract had been depressed; it lies in front of the unruptured anterior hyaloid membrane, and therefore outside the vitreous cavity.