Aqueous humor levels of topically applied levofloxacin, norfloxacin, and lomefloxacin in the same human eyes

PURPOSE: To assess the relative penetration of topical eyedrops of 3 fluoroquinolones into the aqueous humor in human eyes. SETTING: Department of Ophthalmology, Sano-Kosei Hospital, Sano, Japan. METHODS: Fifty-nine cataract patients (36 women, 23 men) received 3 drops each of levofloxacin 0.5%, norfloxacin 0.3%, and lomefloxacin 0.3% in the same eye at 15-minute intervals beginning 90 minutes before cataract surgery. At the beginning of surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analyzed. The drug concentrations in the samples were analyzed using high-performance liquid chromatography. RESULTS: Five patients were excluded from the study because their sample volumes were insufficient. Norfloxacin was detected in 3 patients; the mean aqueous humor level was 0.10 microg/mL +/- 0.02 (SD). Levofloxacin was detected in all cases; the mean aqueous humor level was 0.60 +/- 0.28 microg/mL (n = 54). Lomefloxacin was not detected in 10 patients; the mean aqueous humor level was 0.23 +/- 0.11 microg/mL (n = 44). CONCLUSION: Topically applied levofloxacin had better penetration into the aqueous humor than lomefloxacin and norfloxacin.