[Pathological and immunohistochemical evaluation of keratoepithelioplasty in rats]

Keratoepithelioplasty was performed in the rat and epithelial rejection and epithelial regeneration were evaluated pathologically and immunohistochemically. A mechanical corneal epithelial defect was prepared in Lewis rats. Two lenticules, obtained from DA rats were grafted and postoperative observations were performed using a slit lamp microscope up to the 21st day. The same procedure was performed between Lewis rats only, as the control group (syngeneic model). Eyeballs were enucleated, and Hematoxylin-eosin (H-E) and Periodic Acid Shiff (PAS) staining were performed to allow observation by light microscopy. In addition, eyeballs were examined after staining by the Peroxidase-antiperoxidase (PAP) method using three kinds of monoclonal antibodies (W3/25, OX8 and OX6). Reepithelialization was completed by approximately postoperative day 6. Superficial keratitis occurred at postoperative day 10. Intense infiltration of helper T cells, cytotoxic T cells, Ia antigen positive cells, and neutrophils in the lenticules, regenerated epithelium, and beneath the regenerated epithelium was accompanied by rejection. On postoperative day 21, goblet cells were observed in the lenticules and its regenerated epithelial layer. There were no goblet cells in the lenticule and its regenerated epithelial layer of the control groups. Epithelial rejection began on the lenticular side, and rejected both the lenticules and the regenerated epithelium. The recovered corneal epithelium, migrated from the lenticules seemed to be replaced by regenerating conjunctival epithelium of the recipient.