Decreased Ratio of VEGF165b/VEGF in Aqueous Humor Predicts Progression of Diabetic Retinopathy.

BACKGROUND: Different splicing of vascular endothelial growth factor (VEGF) gene results in two families of VEGF, the pro-angiogenic isoforms (VEGFxxxa) and the anti-angiogenic isoforms (VEGFxxxb). VEGF165b is the major anti-angiogenic isoform of VEGF and the most studied member of the VEGFxxxb family so far. OBJECTIVES: To determine the concentration of VEGF165b and VEGF in the aqueous humor (AH) in diabetic eyes with or without diabetic retinopathy (DR), and to address the predictive value of VEGF165b/VEGF ratio for progression of DR. METHODS: AH samples from 20 eyes in healthy controls (CON group), 40 eyes in diabetic patients without DR (nDR group), and 30 eyes in diabetic patients with mild non-proliferative DR (DR group) were collected. All patients were followed up for at least 5 years. VEGF165b and VEGF level of AH samples were measured by enzyme-linked immunosorbent assay (ELISA). The predictive value of the initial level of VEGF165b /VEGF ratio for progression of DR was studied. RESULTS: Mean concentration of VEGF165b significantly decreased in diabetic eyes versus controls. Mean concentration of VEGF significantly increased in DR group versus CON group. Mean follow-up was 66.1months (range 60-71 months). The VEGF165b/VEGF ratio was significantly lower in diabetic patients compared with control group. The risk of DR progression was greater with lower VEGF165b/VEGF ratio. CONCLUSION: VEGF165b/VEGF ratio is lower in the aqueous humor of DR patients and the decreased ratio of VEGF165b/VEGF predicts DR progression.