The ocular penetration of levofloxacin 1.5% and gatifloxacin 0.3% ophthalmic solutions in subjects undergoing corneal transplant surgery

Objective: To compare corneal tissue and aqueous humor concentrations of levofloxacin 1.5% and gatifloxacin 0.3% ophthalmic solutions after topical dosing. Research design and methods: This was a randomized, observer-masked, parallel-group, multicenter study. Fifty-nine subjects undergoing planned penetrating keratoplasty were randomly assigned to receive either levofloxacin 1.5% or gatifloxacin 0.3% as follows: one drop 15 min prior to surgery and a second drop 10 min before surgery. Corneal button and aqueous humor samples were collected during surgery and immediately stored at -70 degrees C. Levofloxacin and gatifloxacin concentrations were determined by high-pressure liquid chromatography and mass spectrometry. Main outcome measures: Corneal tissue and aqueous humor concentrations of levofloxacin and gatifloxacin. Results: Levofloxacin achieved statistically significantly higher concentrations in both corneal tissue and aqueous humor compared to gatifloxacin in patients undergoing penetrating keratoplasty. In corneal tissue the mean concentration of levofloxacin was 64.8 +/- 123.4 mu g/g vs. 7.0 +/- 9.3 mu g/g for gatifloxacin (p < 0.0001). Mean aqueous humor concentration of levofloxacin was 0.976 +/- 2.215 mu g/mL vs. 0.0523 +/- 0.143 mu g/mL for gatifloxacin (p = 0.0002). Conclusions: The high concentrations of levofloxacin achievable in corneal tissue with topical dosing suggest that levofloxacin 1.5% should be a useful agent in the treatment of ocular bacterial infections. However, the corneal concentrations achieved in this study may not be representative of concentrations in patients using less frequent dosing.