Proliferative retinopathies: Angiogenesis that blinds

Proliferative ischemic retinopathies such as proliferative diabetic retinopathy (PDR), retinopathy of prematurity (ROP) and those stemming from retinal vein occlusion are the leading causes of blindness in the working age and pediatric populations of industrialized countries. They present major financial burdens for health care systems and account for significant loss of productivity. These pathologies are characterized by excessive pre-retinal blood vessel growth that can ultimately lead to a fibrous scar formation and culminate in retinal detachment. This abnormal and disproportionate hyper-vascularization is a compensatory mechanism to overcome an earlier phase of microvessel degeneration and reinstate metabolic equilibrium to the hypoxic retina. To date, the treatment modalities to counter these diseases largely rely on invasive and moderately efficient surgical interventions. In this review, we discuss the current views on retinal vaso-obliteration, neovascularization and available treatments and present future strategies to tackle these diseases. (C) 2009 Elsevier Ltd. All rights reserved.