Intravitreal toxicity of moxifloxacin.

Abstract

To assess the retinal toxicity of various concentrations of intravitreally administered moxifloxacin, a fourth-generation fluoroquinolone. Ten New Zealand albino rabbits were divided into five groups. The initial concentration of moxifloxacin (400 mg/250 mL) was titrated using 5% dextrose solution to concentrations (320 microg/0.1 mL, 160 microg/0.1 mL, 100 microg/0.1 mL, and 50 microg/0.1 mL) that were injected intravitreally into 1 eye of each rabbit. Two control eyes were injected intravitreally with 0.1 mL of 5% dextrose solution. All animals were examined before and after injection by indirect ophthalmoscopy and slit-lamp biomicroscopy; electroretinography (ERG) was performed on all animals. The animals were killed, and their eyes were enucleated and examined with light microscopy. Remarkable decreases in ERG findings were noted in the group injected with moxifloxacin at a concentration of 320 microg/0.1 mL. No meaningful ERG changes were observed in eyes injected with moxifloxacin at other concentrations. There were no signs of retinal toxicity during slit-lamp examination, indirect ophthalmoscopy, or light microscopy in any eyes injected with moxifloxacin concentrations of < or =160 microg/0.1 mL. Intravitreal injection of moxifloxacin at a concentration of < or =160 microg/0.1 mL appeared nontoxic in the rabbit eye.