Confocal assessment of the effects of fourth-generation fluoroquinolones on the cornea.

ABSTRACT

PURPOSE: To evaluate the toxicity of fourth-generation fluoroquinolone antibiotic solutions on the rabbit corneal epithelium. METHODS: In vivo confocal microscopy was used to assess epithelial structure in 18 rabbits, and tight junction integrity of superficial epithelial cells was evaluated with ZO-1 labeling in 10 rabbits. Eyes were bathed with commercial solutions of moxifloxacin (Vigamox) or gatifloxacin (Zymar) solution for 3 minutes, rinsed with balanced salt solution, and immediately examined. Balanced salt solution rinsing alone served as the control. RESULTS: A decrease in epithelial cell size was observed after treatment with Zymar (P < 0.05, two-way repeated-measures analysis of variance), but not with Vigamox or the control. Normal ZO-1 organization was observed in controls and eyes treated with Vigamox. ZO-1 staining in eyes treated with Zymar was disrupted, patchy, and generally weaker than that in control eyes. CONCLUSIONS: After short-term, intensive exposure to Vigamox, corneal epithelial integrity and tight junction organization are maintained. Zymar induces a loss of superficial epithelial cells and breakdown of tight junctions under similar conditions.