The survival and rejection of epithelium in experimental corneal transplants.

Evidence is presented that the epithelium on a donor corneal allograft is neither sloughed off rapidly in the immediate postoperative period, nor is it even slowly replaced by recipient epithelium in the technically successful corneal transplant. Specific immunologic rejection of the surviving epithelium of a graft may take place long after transplantation, and is characterized by a linear defect consisting of dying epithelial cells and inflammatory cells, stainable by topical methylene blue or fluorescein, which defect migrates slowly across the entire surface of the graft until all donor epithelium has been destroyed.