Aqueous humor penetration of gatifloxacin and moxifloxacin eyedrops given in different concentrations in a wick before cataract surgery.
Author(s): Ong-Tone L
Affiliation(s): University of Saskatchewan and Pasqua Hospital, Regina Qu'Appelle Health Region, Regina, Saskatchewan, Canada. firstname.lastname@example.org
Publication date & source: 2008-05, J Cataract Refract Surg., 34(5):819-22.
Publication type: Comparative Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't
PURPOSE: To determine whether the penetration into the aqueous humor of gatifloxacin (Zymar) and moxifloxacin (Vigamox) eyedrops was affected by altering their concentrations in the dilating mixture in which the wick used to dilate the pupil before cataract surgery was soaked. SETTING: Pasqua Hospital, Regina, Saskatchewan, Canada. METHODS: This prospective randomized open-label study comprised 65 women and 35 men who were divided into 2 main groups. One group received 1 mL of the antibiotic in the dilating mixture and the other, 2 mL. Each group was divided into 2 subgroups, 1 for gatifloxacin and 1 for moxifloxacin. At the beginning of surgery, 0.1 mL of aqueous humor was aspirated, frozen, and couriered to the provincial laboratory for analysis by high-performance liquid chromatography. RESULTS: In the first group, the mean concentration of gatifloxacin in the aqueous humor was 0.30 microg/mL +/- 0.21 (SD) and of moxifloxacin, 0.97 +/- 0.63 microg/mL. When the volume of the antibiotic in the dilating mixture was doubled, the mean concentration increased to 0.34 +/- 0.25 microg/mL and 1.37 +/- 0.79 microg/mL, respectively. Only the increased penetration of moxifloxacin was statistically significant. CONCLUSIONS: Moxifloxacin penetrated the aqueous humor better than gatifloxacin when given in a wick soaked in the dilating mixture before cataract surgery. Only the penetration of moxifloxacin increased significantly when the volume of the antibiotic in the dilating mixture was doubled. In both groups, only moxifloxacin reached and exceeded the minimum inhibitory concentration levels for the most common ocular pathogens causing endophthalmitis.