A comparison of plasma and vitreous levels of angiogenic factors [Vascular Endothelial Growth Factor, soluble VEGF receptor, Angiopoietin 1 & 2, and angiopoietin receptor TIE 2] in proliferative diabetic retinopathy

Abstract

Abstract: : Purpose: To compare plasma and vitreous levels of angiogenic factors [Vascular Endothelial Growth Factor (VEGF, in index of angiogenesis), soluble VEGF receptor (sFlt–1), Angiopoietin 1 & 2 (Ang–1, Ang–2) and soluble angiopoietin receptor TIE 2 (tie–2)] in patients with proliferative diabetic retinopathy undergoing vitrectomy. Methods: 23 patients (18 male), mean age 51 years (range 25 to 72) with proliferative retinopathy secondary to diabetes and with no previous vitreo–retinal surgery were studied. Plasma and undiluted vitreous samples were obtained on the day of surgery. Plasma and vitreous levels of VEGF, sFLT–1, Ang 1 and 2 and tie 2 were assayed using ELISA. 

Results are median (inter–quartile range). P value for difference between plasma and vitreous levels, using 1–sample Wilcoxon test. Conclusions: Patients with proliferative diabetic retinopathy did not demonstrate statistically significant differenced between peripheral and vitreal markers of angiogenesis. As previous studies have shown significantly raised levels of angiogenic markers in proliferative diabetic retinopathy, plasma levels of these indices might be useful in determining patients at risk of developing proliferative retinopathy and provide an indicator for early treatment. A change in the plasma levels after vitrectomy may provide an opportunity for monitoring disease progression or relapse via a blood sample.

Keywords: diabetic retinopathy • retinal neovascularization • vitreoretinal surgery