Effects of intravitreally injected bevacizumab on vascular endothelial growth factor in fellow eyes

Abstract

Abstract Purpose To determine the level of vascular endothelial growth factor (VEGF) in the fellow eyes after an intravitreal injection of bevacizumab in one eye. Methods Eight patients who had similar findings of with proliferative diabetic retinopathy (PDR) in both eyes were studied (four patients had rubeosis, and four patients did not have rubeosis in the anterior chamber). All patients received an intravitreal injection of bevacizumab(1.25 mg) in one eye. Samples of aqueous humor were collected from the injected eyes just before and one day after the injection, and after 7 days from untreated fellow eyes. The concentration of VEGF was measured by ELISA. Results After one day, the VEGF level in injected eyes was significantly reduced from 3230.3±2136.8 pg/ml to 3.1±3.6 pg /ml (P<0.05) in eyes with rubeosis and 465.0±78.8 pg/ml to 0 pg/ml (P<0.05) in those without rubeosis. After seven days, the VEGF levels of the fellow eyes were still significantly lower than that in the injected eyes before the injection (688.5±443.1 pg/ml in the rubeosis group, and 7.8±13.2 pg/ml in the no rubeosis group, P<0.05, P<0.05). Conclusion A single intravitreal injection of bevacizumab significantly reduced the VEGF concentrations in the aqueous humor of the fellow untreated eye.