Corneal UV Protective Effects Of A Topical Antioxidant Formulation: A Pilot Study On In Vivo Rabbits

Abstract

Background The purpose of this study has been to evaluate the protective effect of a topical antioxidant and UV schielding action formulation containing riboflavin, d-α-tocopheryl polyethylene glycol (TPGS vitamin E), against corneal UV-induced damage in vivo rabbit eyes. Methods For the evaluation, in vivo experiments were performed using twelve male albino rabbits. Animals were divided into 4 groups of 3 animals each: control group (CG) didn’t receive any UV irradiation; the first group (IG) was irradiated with an UV-B - UV-A lamp for 30 min; the second (IG30) and the third (IG60) groups received UV irradiation for 30 and 60 minutes, respectively, and were topically treated with 1 drop (approximately 50 µl) of the antioxidant and shielding formulation every 15 minutes, starting one hour before irradiation, until the end of UV exposure. Results The cornea of IG group showed irregular thickening, detachment of residual fragments of the Descemet membrane, stromal fluid swelling with consequent collagen fibers disorganization and disruption, and inflammation. The cornea of G30 group showed edema, a mild thickening of Descemet membrane without fibrillar collagen disruption and focal discoloration, nor inflammation. In the G60 group cornea showed a more severe thickening of the cornea, a more abundant fluid accumulation underneath the Descemet membrane, with focal detachment of the same, and no signs of severe tissue alterations, as those recorded in the IG group. Conclusion Our results demonstrate that a topical application of eye drops containing riboflavin, d-α-tocopheryl polyethylene glycol (TPGS vitamin E) counteracts UV corneal injury in exposed rabbits.