Aqueous humor levels of topically applied levofloxacin in human eyes

Purpose. To evaluate transcorneal penetration of topically applied 0.5% levofloxacin into the aqueous humor in human eyes. Methods. Twenty cataract patients (14 females, 6 males) received 3 drops of 0.5% levofloxacin at 15 min intervals from 90 minutes before the surgery. At the beginning of the cataract surgery, 50 muL of aqueous humor was aspirated from the anterior chamber and stored at -80degreesC until analysis. The drug concentration of the samples was analyzed using high-performance liquid chromatography. Results. A mean aqueous humor level of levofloxacin was 1.00 +/- 0.48 mug/mL (mean +/- standard deviation, n = 20), ranging from 0.30 mug/mL to 2.32 mug/mL. Conclusions. The mean concentration of levofloxacin in the aqueous humor was higher than the MIC90 values against some common pathogens of postoperative endophthalmitis, although a great degree of interpatient variability was present.