Corneal wound healing in New Zealand white rabbits following anterior keratectomy and treatment with moxifloxacin ophthalmic solution 0.5% or gatifloxacin ophthalmic solution 0.3%

Purpose: These studies examined corneal reepithelialization rates and type IV collagen expression in rabbits treated with either moxifloxacin HCl ophthalmic solution 0.5% as base or gatifloxacin 0.3% ophthalmic solution following anterior keratectomy. Methods: Animals (n = 6 per group) underwent surgery to create an 8-mm anterior keratectomy in the right eye. Rabbits were subsequently dosed with 1 drop, 3 times per day for 4 days with either moxifloxacin, gatifloxacin, or a commercially available irrigating solution. Fluorescein images were collected daily for the duration of the study. Approximately 96 h following surgery, the eyes were processed and evaluated for the presence of type IV collagen using immunohistochemical techniques. In two similar parallel studies, epithelial tissues were collected after the 48-h slit-lamp examination for a quantitative comparison of type IV collagen using either Western blot or quantitative polymerase chain reaction (Q-RT-PCR) techniques. Results: Analysis of fluorescein images demonstrated that there were no significant differences in reepithelialization rates between the groups at any time point. At 96 h, 87% ± 8% reepithelialization for moxifloxacin-treated eyes was observed compared with 77% ± 10% for gatifloxacin-treated eyes and 85% ± 14% for BSS-treated eyes. The wound healing rates for the parallel studies demonstrated similar levels of reepithelialization for all groups. No discernable differences in type IV collagen expression were observed between treatment groups in the animals. The Q-RT-PCR analysis yielded no significant quantifiable difference in type IV collagen expression between any of the treatment groups. Expression values for α1 type IV collagen relative to the 18 S ribosomal RNA control were 0.0306 ± 0.005 for BSS, 0.0251 ± 0.002 for moxifloxacin, and 0.0254 ± 0.006 for gatifloxacin. Conclusions: These studies indicate that there are no significant differences in corneal reepithelialization rates and type IV collagen expression between moxifloxacin ophthalmic solution 0.5%, gatifloxacin ophthalmic solution 0.3%, and the commercially available irrigating solution in this anterior keratectomy model.