Replacement of traumatic iris prolapse.

THE various text-books of eye-surgery, in dealing with traumatic iris prolapse, give the traditional advice to cut the prolapsed iris tissue flush with the corneal surface, after having firmly pulled out the iris through the wound so that the cut edges of the iris may retract away. from the corneal laceration. The result is usually a more or less broad disfiguring coloboma with the known drawbacks of dazzling and photophobia, particularly when the coloboma is in the lower part of the eye. Though Stallard (1950) recommends reducing a small post-operative subconjunctival iris prolapse by stroking the iris back into the anterior chamber, in cases of penetrating injuries where the iris is in direct communication with the conjunctival sac and infection is likely, the principle of his treatment is not replacement but abscission, making as small a colomba as is compatible with, avoiding anterior synechiae. But even with the excision of a prolapse performed in the classical way one may not always achieve an ideal retraction of the pillars away from the wound, especially where the wound is concentric to the limbus and about midway between limbus and corneal centre and/or has slanting edges. Pulling the iris sufficiently out in such cases is dangerous in that the iris may tear at its root. Spaeth (1948) recommends a fresh keratome incision at the limbus near the perforation and withdrawing the iris from the perforation wound' through this new incision. For some of these cases, particularly in freshly sustained injuries, he advises releasing the iris from the perforation and smoothing it flat. He states that, in general, these cases of traumatic iris prolapse are best handled by abscission of the prolapsed iris. Duke-Elder (1954) writes that prolapsed uveal tissue should never be replaced because of the risk of introducing infection into the eye. Because the new antibiotics now make it possible to prevent or combat nearly all forms of infection, and because of the beneficial effect of the corticosteroids on inflammatory reactions, the excision of an iris prolapse seems to us no longer necessary. On the basis of experience gained from handling anterior synechiae in leucoma adherens prior to corneal grafting, a method has been developed of replacing prolapsed iris by a manoeuvre from inside