Relationship between Macular Thickness and the Ratio of Vascular Endothelial Growth Factor to Its Soluble Receptor 1 in Non-Proliferative Diabetic Retinopathy

Abstract

Background: The goal of this study was to determine the ratio of vascular endothelial growth factor (VEGF) to soluble VEGF receptor 1 (SVEGFR1) in aqueous humor of patients with non-proliferative diabetic retinopathy (NPDR). We also investigated the association between this ratio and macular edema. Methods: In this randomized, cross-sectional study, aqueous humor was collected during Avastin injection in ocular fluid of patients with NPDR. Concentrations of VEGF and SVEGFR1 were then determined. Macular thickness was measured with ocular coherence tomography (OCT). Findings: VEGF/SVEGFR1 had a significant correlation with macular thickness (r = 0.46; P = 0.05). Therefore, imbalance between VEGF and its soluble receptor in ocular fluid is related with macular edema. Conclusion: Decreased level of SVEGFR1 increases the activity of VEGF. As a result, vessels in retina become permeable. This pro-angiogenic factor will in turn increase macular edema. Keywords: Angiogenesis, Macular edema, Vascular endothelial growth factor, Non-proliferative diabetic retinopathy, Optical coherence tomography