Effect of Quick Freezing at Very Low Temperatures of Donor Tissue in Gorneal Transplants.

Abstract

Fifteen corneal transplantations were performed on rabbits by Castroviejo''s method. The donor tissue was rabbit corneas frozen in either liquid iso-pentane chilled with liquid N, or liquid N alone, and rapidly thawed just prior to implantation. A control series consisting of 21 keratoplasties was made with living donor tissue. The same operating technique and post-operative treatment was used in both sets of experiments. The results showed 13 perfectly healed transparent grafts in the series where living corneal tissue was used as donor material, with 8 nebulous, incompletely healed, or opaque transplants. All of the grafts made from frozen corneas were healed perfectly after a slight delay, but became opaque and vascular. These results support the theory that living tissue is required for the production of permanently transparent grafts and that the corneal strotna of a clear graft retains its identity as donor tissue for at least a long period of time.