Penetrating Corneal Graft with Posterior Flange: Preliminary Observations on Rabbits

A simple technique, identical for the donor and recipient cornea, has been devised to achieve a posterior half-thickness flange extending 0.5–1.5 mm beyond the edge of a full-thickness corneal graft. A half-thickness cut with, say, a 5 mm diameter trephine is made. Four radial cuts, also at half-thickness depth, are made 90° apart outwards from that 5 mm diameter groove. Four flaps consisting of the superficial half of the cornea are dissected outwards from the circular groove for a distance of a little more than, say, 1 mm. With these four flaps retracted, a trephine of, say, 7 mm diameter is applied concentric with the 5 mm diameter central pillar: a full-thickness cut is made, if necessary completed with curved scissors. A donor graft with the same configuration takes the place of the discarded recipient. The radial cuts are secured with separate direct sutures: the donor-host junctions are sutured with separate and/or continuous sutures. Excellent alignment of the anterior surface of the graft-host junction was achieved in 5 rabbit corneas operated; a sixth eye suffered an iris prolapse because a suture cut out. Ectasia, opacification and vascularization of the grafts along with anterior synechiae adversely affected the results in all but the sixth eye. Extreme thinness of the rabbit's cornea accounted for most of these complications which should be avoidable in the next series of experiments on sheep and dogs.