Erythropoietin as a retinal angiogenic factor in proliferative diabetic retinopathy

Abstract

Although retinal neovascularization in proliferative diabetic retinopathy(PDR) is a major cause of legal blindness, its mechanism is not fully understood. In this study, we focused on the angiogenic activity of erythropoietin (Epo) and evaluated its potential role in treating retinal angiogenesis in PDR. METHODS: We measured Epo and vascular endothelial growth factor (VEGF) levels in the vitreous fluids of 73 PDR patients and 71 nondiabetic (NDM) patients. We evaluated Epo expression and regulation in retinal neovascularization with soluble Epo receptor. RESULTS: The vitreous Epo level was significantly higher in patients with PDR than in NDM patients. Multivariate logistic-regression analyses indicated that Epo and VEGF were independently associated with PDR and that Epo was more strongly associated with PDR than VEGF was. The blockade of Epo inhibited retinal neovascularization in vitro and in vivo. CONCLUSIONS: Our data suggest that Epo is a potent angiogenic factor that acts independently of VEGF during retinal angiogenesis in PDR.