Penetration of topically applied gatifloxacin 0.3%, moxifloxacin 0.5%, and ciprofloxacin 0.3% into the aqueous humor

Purpose: To investigate the aqueous penetration of 3 commercially available ophthalmic fluoroquinolones. Design: Prospective, double-masked, clinical study. Participants: Fifty-two eyes of 52 patients. Intervention: Fifty-two patients undergoing cataract surgery were given preoperative topical gatifloxacin 0.3% (Zymar), moxifloxacin 0.5% (Vigamox), or ciprofloxacin 0.3% (Ciloxan). The patients were instructed to use their antibiotic drops 4 times a day for 3 days before surgery. On the day of surgery, patients were given their assigned antibiotic every 15 minutes for 3 doses, 1 hour before their procedure. At the time of surgery, 0.1 ml of aqueous fluid was aspirated from the anterior chamber with an air cannula needle attached to a tuberculin syringe. The aspirate was immediately stored at -70degrees C. Main Outcome Measure: Fluoroquinolone concentrations were determined by reverse-phase high-pressure liquid chromatography assay technique with ultraviolet detection at a wavelength of 275 nm. Results: Mean aqueous concentration of gatifloxacin in 16 eyes was 0.63 mug/ml (standard deviation [SD], 0.30), moxifloxacin in 14 eyes was 1.31 mug/ml (SD, 0.46), and the mean concentration of ciprofloxacin in 22 eyes was 0.15 mug/ml (SD, 0.11). Conclusions: Both moxifloxacin (P<0.001) and gatifloxacin (P<0.005) penetrated the aqueous humor at significantly higher levels than ciprofloxacin. Moxifloxacin penetrated into the aqueous humor at significantly higher levels than gatifloxacin (P<0.05). The anterior chamber levels of moxifloxacin and gatifloxacin may be due to the difference in antibiotic concentration. (C) 2005 by the American Academy of Ophthalmology.