Bevacizumab is not toxic to retinal ganglion cells after repeated intravitreal injection.

PURPOSE: The cytotoxicity of single and repeated administration of bevacizumab to retinal ganglion cells was studied in vivo and in vitro. METHODS: Rats received single or repeated injections of 125 microg of bevacizumab into the vitreous cavity of the left eye, while saline was injected into the right eye as a control. In the repeated injection group, bevacizumab was injected at the same concentration once per week for 4 weeks. Retinal ganglion cells were retrogradely labeled with Fluorogold dye, and counted after kill at 0 and 6 months after treatment. In the in vitro study, PC12 cells were cultured in various concentrations of bevacizumab (0, 1, 2, 5, and 10 mg/mL) to model retinal ganglion cells exposure. Cell viability in each group was assessed by an MTT assay. RESULTS: There was no significant difference in retinal ganglion cell numbers between control and bevacizumab-treated eyes following either single or repeated injection, or did bevacizumab have any significant influence on PC12 cell viability in vitro. CONCLUSION: These results suggest that intravitreal injection of bevacizumab poses no risk to retinal ganglion cells, even after repeated application.