KERATOCYTE LOSS AFTER CORNEAL DEEPITHELIALIZATION IN PRIMATES AND RABBITS

Purpose: To evaluate the response of stromal keratocytes to central corneal deepithelialization. Methods: Rabbits and monkeys underwent unilateral mechanical deepithelialization with a blunt instrument and were killed at intervals ranging from 15 minutes to 24 hours after surgery. Two rabbits underwent unilateral deepithelialization under a fluid bath containing corneal preservation medium. Two rabbits were treated unilaterally with corneal preservation medium topically applied every 15 minutes for 16 hours after epithelial removal. Four rabbits underwent linear keratotomy immediately after deepithelialization of the cornea or on normal unoperated corneas and were killed 1 day (two animals) and 14 days (two animals) after surgery. Results: Deepithelialization resulted in severe ultrastructural changes in keratocytes within 30 minutes after surgery. After 24 hours, the number of keratocytes in the anterior stroma underneath the deepithelialized area had decreased significantly in rabbits (P=.0001) and in monkeys (P=.0007) compared with controls. The wound healing was altered and delayed when the epithelium was not present after keratotomy. The use of storage media during and after deepithelialization minimized the early keratocyte changes and appeared to stimulate reepithelialization. Conclusions: Removal of corneal epithelium causes loss of superficial stromal keratocytes in rabbits and monkeys. Keratocyte death may result from osmo tie changes that alter the corneal wound healing response.