Role of Anti Vascular Endothelial Growth Factor agents in the treatment of Retinopathy of Prematurity

Abstract

Retinopathy of Prematurity (ROP) is a proliferative disease occurs in the incompletely vascularized retina of premature babies. It is an important cause of blindness in children in both developed and developing countries. ROP is described by severity (5 stages), location by zone (I-III), extent by clock hours or sector quadrant and by the presence of pre-plus and plus disease. The developing retinal vasculature of premature infants is extremely vulnerable, and perturbation of the normal developmental processes can result in retinopathy of prematurity. Vasculogenesis provides a mechanism for rapid formation of a rudimentary vascular plexus in the regions previously invaded by vascular precursor cells and that this plexus is then expanded by angiogenesis to satisfy the increasing metabolic needs of the developing retina. The mechanism of retinal vascularization is thus similar to that of vascularization of the brain during development Hypoxia stimulates VEGF production which induces neovascularization at the border between vascularized and non-vascularized retina, with in the worse case is ending in retinal detachment. Although VEGF and oxygen play an important role in the development of retinal blood vessels, it is clear that other biochemical mediators also are involved in the pathogenesis.