Comparison of ophthalmic gatifloxacin 0.3% and ciprofloxacin 0.3% in healing of corneal ulcers associated with Pseudomonas aeruginosa-induced ulcerative keratitis in rabbits

Objective: Evaluation of gatifloxacin 0.3% ophthalmic solution efficacy in a corneal ulcer model of Pseudomonas keratitis. Methods: Heptanol-induced corneal ulcers in New Zealand White rabbits (n = 41; 8 females/group) were inoculated with 10(6) CFU of Pseudomonas aeruginosa. Gatifloxacin 0.3% dosing varied among 4 groups with frequencies of 16-48 doses/day (days 1-2), 3-16 doses/day (days 3-7), and maintenance dosing of 3-4 doses/day (days 8-22). Ciprofloxacin 0.3% was administered as labeled for corneal ulcers, with 44 doses on day 1, 16 doses on day 2, and 4 doses/day on days 3-21. Results: All eyes showed evidence of infection by 48 hours postinoculation with 36 of 41 eyes (87.8%) exhibiting moderate-to-severe keratitis. All eyes exhibited corneal healing by day 15, with no significant differences among groups. Three of 4 groups receiving gatifloxacin tended to have smaller fluorescein retention area scores than did the ciprofloxacin group. No eyes tested positive for Pseudomonas at the end of the study. No corneal precipitates were found following as many as 48 doses/day of gatifloxacin. Conclusion: Ophthalmic gatifloxacin 0.3% is at least as effective as ciprofloxacin at healing corneal ulcers infected with Pseudomonas aeruginosa when gatifloxacin is administered less frequently than ciprofloxacin. Trends favored gatifloxacin in fluorescein retention scores.