Vascular Endothelial Growth Factor in Plasma and Vitreous Fluid of Patients with Proliferative Diabetic Retinopathy Patients after Intravitreal Injection of Bevacizumab

PURPOSE: To investigate plasma and vitreous vascular endothelial growth factor (VEGF) levels after intravitreal bevacizumab (IVB) injection into eyes with proliferative diabetic retinopathy (PDR). DESIGN: Retrospective, interventional, nonrandomized, comparative study. METHODS: Fifty-six eyes of 56 patients with PDR and 13 eyes of 13 patients with nondiabetic ocular diseases were enrolled. Analysis included evaluation of basic clinical conditions and measurement of vitreous and plasma VEGF concentrations using enzyme-linked immunosorbent assays. RESULTS: PDR eyes without IVB had the highest vitreous VEGF levels; the levels were significant compared with those in the recent IVB group (previous injection within 1 week), the prolonged IVB group (injection more than 1 week previously), and the nondiabetic control group (P = .001, P = .035, P < .001, respectively). The vitreous VEGF level in the recent IVB group was higher than that in prolonged IVB group (P = .035). PDR eyes without IVB had the highest plasma VEGF level, and the level was significant compared with those in the recent IVB group, the prolonged IVB group, and the nondiabetic control group (P < .001, P = .003, P < .001, respectively). The plasma VEGF level in the recent IVB group was lower than that in the prolonged IVB group (P = .003). The vitreous VEGF level was associated significantly with the plasma VEGF level (P = .002). CONCLUSIONS: Vitreous and plasma VEGF levels were increased markedly in patients with PDR. VEGF concentrations in vitreous and plasma were decreased significantly after IVB into PDR eyes, and the effect lasted from 4.4 +/- 2.2 days to 34.8 +/- 33.7 days after injection. (Am J Ophthalmol 2012;153:307-313. (C) 2012 by Elsevier Inc. All rights reserved.)