Collagen shield delivery of ofloxacin to the human eye

Purpose: To determine the ocular penetration of ofloxacin into the anterior chamber of the human eye when delivered by a presoaked collagen shield. Setting: University of Colorado School of Medicine, Denver, Colorado. Methods: This prospective randomized clinical study comprised 31 patients having cataract surgery. Patients were divided into 2 groups: the first received 3 preoperative drops of commercially available topical ofloxacin 0.3% given 10 minutes apart; the second had a collagen shield soaked in the same medication applied to the eye before surgery. Aqueous humor was extracted immediately before surgery for analysis. Results: Mean aqueous concentration was 287 ng/mL +/- 69 (SEM) (range 40 to 1141 ng/mL) in the drops group and 957 +/- 189 ng/mL (range 214 to 2437 ng/mL) in the shield group. The difference was statistically significant (P < .005). The minimum inhibitory concentration (MIC) for selected ocular pathogens is between 500 and 4000 ng/mL. Conclusions: A collagen shield presoaked in commercially available topical ofloxacin and applied before surgery appears safe. The MICs for many common ocular pathogens were reached or exceeded. Further study is recommended to determine whether this method of infection prophylaxis is an acceptable substitute for subconjunctival injections of antibiotics.