Effect of Topical Moxifloxacin on the Bacterial Flora of the Ocular Surface following Cataract Surgery: A Randomized, Single-Masked Clinical Trial

Abstract

Objective: To determine the efficacy of topical 0.5% moxifloxacin ophthalmic solution in reducing conjunctival flora when administered for 3 days versus 1 hour prior to surgery. Methods: This was a randomized, single-masked, comparative, longitudinal, single-center study. Sixty eyes of 60 patients scheduled for cataract surgery were randomized to receive either 1 drop of moxifloxacin 4 times daily for 3 days prior to surgery or 1 drop every 15 minutes for 1 hour prior to surgery. The non-surgical eye of each patient served as the no-treatment control. Conjunctival cultures were obtained from both eyes at baseline (t0) and 1 hour after the last dose of treatment (t1). Results: There was no statistically significant difference (p = 0.54) in the percent of culture-positive eyes between the 3-day and 1-hour groups at baseline; however, the difference was statistically significant (p = 0.035) in favor of the 3-day group at t1. The mean number of colony forming units (CFU) was significantly lower at t1 compared to t0 in the 3-day group (p = 0.04), but not in the 1-hour group (p = 0.73). At t1, eyes in the 3-day group showed statistically significant reduction in the percent of culture-positive eyes (p = 0.019) and the mean number of CFU (p = 0.002) for S. epidermidis; the most frequently isolated organism from swab samples at t0 and t1. No treatment-related adverse events were reported. Conclusion: The 3-day prophylactic regimen with 0.5% moxifloxacin ophthalmic solution resulted in statistically significantly fewer positive conjunctival cultures and fewer CFU than the 1-hour regimen, suggesting 3-day regimen would prevent postoperative endophthalmitis.