Anti-Angiogenic Isoforms of Vegf Predominate in Subretinal Fluid of Patients With Rhegmatogenous Retinal Detachment and Proliferative Vitreoretinopathy

Abstract

Purpose: : Vascular endothelial growth factor (VEGF) plays an essential role in the development of physiological and pathological angiogenesis. In proliferative vitreoretinopathy (PVR), a non-angiogenic eye disease that is characterized by the formation of mainly avascular membranes, VEGF levels are found to be up-regulated. Recently, it was discovered that VEGF is alternatively spliced to form the angiogenic (VEGF_xxx) and anti-angiogenic (VEGF_xxxb) family of isoforms. Previous studies on expression of VEGF in PVR samples have not distinguished between the two families of isoforms.

Methods: : Total VEGF and VEGF_xxxb levels were measured in subretinal fluid of patients with PVR (n = 10) and uncomplicated rhegmatogenous retinal detachment (RRD; n = 27) using enzyme-linked immunosorbent assay

Results: : Total VEGF levels in PVR patients were significantly higher than in patients with uncomplicated RRD (p = 0.047). Anti-angiogenic VEGF_xxxb isoforms predominate and account for about two-thirds of the total VEGF in both groups: 69% in the PVR negative samples compared to 64% in the PVR positive samples.

Conclusions: : The absence of an angiogenic switch of VEGF may explain a lack of blood vessels in PVR membranes. Elevated VEGF levels indicate that this cytokine may play a role in the pathogenesis of PVR that is not related to angiogenesis.

Keywords: proliferative vitreoretinopathy • retinal detachment • growth factors/growth factor receptors