Vascular endothelial growth factor in fellow eyes of eyes injected with intravitreal bevacizumab

Abstract

To study the effect on untreated fellow eyes of eyes treated with an intravitreal injection of bevacizumab. Bevacizumab (1.25 mg/0.05 ml) was injected into the vitreous cavity of one eye (the first eye) as a preoperative adjunctive therapy for proliferative diabetic retinopathy; vitrectomy was performed 1 week later. Immediately after vitrectomy, bevacizumab (1.25 mg/0.05 ml) was injected into the fellow eye (the second eye) followed by vitrectomy 1 week later. Aqueous humor samples were obtained from both eyes in five cases just before intravitreal injection of bevacizumab and just before vitrectomy 1 week later. Vascular endothelial growth factor (VEGF) concentrations in the aqueous humor were measured by enzyme-linked immunosorbent assay (ELISA). VEGF concentrations in the aqueous humor of the first eyes ranged from 146 to 398 pg/ml (mean, 302+/-100 pg/ml) before intravitreal injection of bevacizumab; 1 week later, the VEGF concentrations in the injected eyes were less than 31 pg/ml, the lower limit of the ELISA, in all cases (p<0.001). The concentrations in the uninjected fellow eyes ranged from 181 to 551 pg/ml (mean, 382+/-119 pg/ml). There seemed to be no or a minimal effect of the intravitreal injections of bevacizumab on the uninjected fellow eyes.