Simple organ cornea culture model for re-epithelialization after in vitro excimer laser ablation

Background and Objective: Most of the in vitro work to characterize the eff ects of clinical laser surgery on corneal tissues has concentrated on the e ffects on stromal keratocytes and endothelium with little attention being p aid to corneal epithelium. Our purpose is to describe the epithelial healin g rates observed in freshly cultured rabbit corneas treated with photothera peutic keratectomy (PTK). Study Design/Materials and Methods: Corneas were placed in a simple organ c ulture system, with media change every 2 days. A clinical excimer laser was used to perform a 6 mm. diameter, 100 mum depth transepithelial PTK on 24 cultured rabbit corneas, 1 day after culture initiation. For each post-trea tment day, one experimental and one control cornea were removed from cultur e and stained with fluorescein, photographed, and fixed for histology. Epit helial defect area was measured with digital imaging software and analyzed statistically to assess the re-epithelialization rate. Results: Control corneas, maintained in culture for 1-4 days, had no epithe lial defects. Those corneas treated with PTK exhibited an immediate epithel ial defect that slowly healed over 3 days. This was confirmed on histopatho logical analysis. A significant linear trend in re-epithelialization across the time points studied was found (F = 80.48, P = 0.0029). The slope of th e linear regression model showed an estimate rate of re-epithelialization o f -6.70 over the 3 days. Conclusion: We have described the development of a simple, whole organ, rab bit cornea culture model for reepithelialization after PTK. Our rates of ep ithelial healing resemble those found in the literature in live rabbit mode ls. Therefore, this model may possibly be used to monitor epithelial wound healing in different corneal diseases or injuries. (C) 2001 Wiley-Liss, Inc .