Keratocyte Loss and Repopulation of Anterior Corneal Stroma After De-epithelialization

Objective: To quantitate corneal keratocyte loss and repopulation of anterior stroma after de-epithelialization. Methods: Fourteen white New Zealand rabbits, each weighing 2.3 to 3.2 kg, were divided into seven groups. Each rabbit underwent a bilateral 6-mm mechanical de-epithelialization procedure. The rabbits were killed two at a time after 1, 3, 6, 8, 10, 14, and 28 days. The corneas were labeled for mitosis using 5-bromo-2-deoxyuridine and stained for keratocyte quantification. Three untreated rabbits were added as controls. Results: Corneas that were not operated on showed a higher density of keratocyte nuclei within the anterior corneal stroma than in the posterior stroma. Following de-epithelialization, there was a decrease in the ratio of anterior-posterior keratocytes, with maximal decrease on the third postoperative day. Keratocyte repopulation was completed by day 14. Mitotic activity was seen on days 1, 3, and 6 in the anterior half of the de-epithelialized stroma. Conclusions: Anterior stromal keratocytes are lost after epithelial removal, but repopulation is complete within 2 weeks. These findings demonstrate a loss of keratocytes and their recovery after corneal epithelial removal, as well as an interaction between corneal epithelium and stroma in rabbits.