Differential Aqueous and Vitreous Concentrations of Moxifloxacin and Ofloxacin After Topical Administration One Hour before Vitrectomy

PurposeTo investigate the penetration of ofloxacin and moxifloxacin into the aqueous and vitreous after topical administration one hour before vitrectomy surgery.DesignProspective, randomized, double-blind case series study.MethodsTwenty-seven patients undergoing vitrectomy were randomized to receive either topical ofloxacin 0.3% or moxifloxacin 0.5% every 10 minutes for one hour before surgery. Aqueous and vitreous samples were obtained and analyzed using high-performance liquidation chromatography.ResultsThe moxifloxacin aqueous (1.576 ± 0.745 μg/ml) and vitreous (0.225 ± 0.013 μg/ml) levels were significantly higher than the ofloxacin aqueous (0.816 ± 0.504 μg/ml) (P = .0009) and vitreous (0.225 ± 0.013 μg/ml) [P = .0054] levels, respectively. The mean moxifloxacin aqueous and vitreous levels exceeded the minimum inhibitory concentration for 90% of isolates (MIC90) for a wide variety of bacteria implicated in endophthalmitis. In contrast, the aqueous level of ofloxacin exceeded the MIC90 of only a few organisms.ConclusionsMoxifloxacin applied every 10 minutes during the hour before vitrectomy penetrated the eye significantly better than ofloxacin.