EFFICACY OF TOBRAMYCIN-SOAKED COLLAGEN SHIELDS VS TOBRAMYCIN EYEDROP LOADING DOSE FOR SUSTAINED TREATMENT OF EXPERIMENTAL PSEUDOMONAS-AERUGINOSA-INDUCED KERATITIS IN RABBITS

We compared the efficacy of a fortified tobramycin-soaked collagen shield to the efficacy of a single loading dose (four 50-mu-l drops) of fortified tobramycin eyedrops in the treatment of New Zealand White rabbits with Pseudomonas aeruginosa-induced keratitis. Eyedrop loading-dose efficacy was evaluated with and without lateral tarsorrhaphy. Six hours after a single treatment, significantly fewer Pseudomonas colonies were present in the corneas of all three drug-treated groups as compared to the number of colonies in the corneas of balanced salt solution-treated control rabbits (P < .006). Although no significant difference was observed between any of the drug-treated groups, lateral tarsorrhaphy was associated with a greater than tenfold decrease in the number of colony-forming units (P = .073). We found no significant difference in efficacy between a collagen shield presoaked in tobramycin, and a single loading dose of tobramycin eyedrops, in the treatment of rabbits with P. aeruginosa-induced keratitis.