THE HEALING EFFECT OF ALL-TRANS-RETINOIC ACID ON EPITHELIAL CORNEAL ABRASIONS IN RABBITS

Purpose: The aim of the study was to investigate the possible healing effect of the vitamin A analogue all-trans retinoic acid 0.05% (Rk) in vaseline on epithelial corneal abrasions in 13 ocularly healthy Copen hagen white rabbits, Methods: A corneal abrasion with a diameter of 6 mm was created centrally in both eyes with a trephine and subsequent r ubbing off of the corneal epithelium with an n-heptanol soaked swab. T he corneal abrasions were treated twice daily with topical application s (50 mu l); RA was placed in the right inferior fornix and its vaseli ne vehicle in the left inferior fornix, Photographic documentation of fluorescein stained, non-healed areas, was performed at time points 0, 12, 24, 36, 48 and 72 h, The rabbits were sacrificed by aln overdose o f pentobarbital and enucleated, Planimetry was performed from corneal photographs. Results: Healed epithelial mean area at time point 36 h w as significantly higher after RA compared to vehicle (p = 0.036, paire d t-test), Median time to 75% and 85% healing was significantly shorte r for RA compared to vehicle (p = 0.03 and 0.02, log rank-test). No mo rphological difference, evaluated by light microscopy (hematoxylin-eos in) or scanning electron microscopy, was noted between the two treatme nts. Conclusion: It is concluded that RA 0.05% applied twice daily inc reases the healing rate compared to vaseline vehicle.