Anti-VEGF Therapy as an Emerging Treatment for Diabetic Retinopathy

Abstract

Anti-VEGF therapies are currently under investigation for diabetic maculopathy. Both clinical and preclinical findings have implicated vascular endothelial growth factor (VEGF) in the pathophysiology of diabetic macular edema (DME). VEGF is involved both in vascular integrity and leakage as well as neovascularization. VEGF levels are elevated in the vitreous of patients with diabetic macular edema, and in animal models elevated VEGF levels in the eye coincide with breakdown of the blood-retinal barrier. Two VEGF antagonists are FDA approved for the clinical treatment of neovascular age-related macular degeneration: pegaptanib and ranibizumab. Phase II data for pegaptanib are available demonstrating a superior visual acuity for treated patients compared to the sham group as well as a reduced retinal thickness and a reduced need for laser therapy. Phase I data for ranibizumab in diabetic macular edema demonstrated a reduction in excess retinal thickness and improvement in visual acuity. Phase II studies are underway to compare ranibizumab and laser photocoagulation.