Retinopathy of prematurity after Oxygen therapy, a prospective study in NICUs, Fayoum, Egypt

Abstract

Retinopathy of prematurity (ROP) is a vasoproliferative disease of an immature retina in premature neonates. It is the commonest cause of preventable blindness in infancy and childhood. ROP progresses in two phases. The first phase begins with delayed retinal vascular growth after birth and partial regression of existing vessels, followed by a second phase of hypoxia-induced pathological vessel growth. Two major risk factors of ROP are the use of Oxygen and a decreased gestation period. The relation between hyperoxia, low-gestational age, growth retardation, Oxygen dependent growth factors, and oxidative stress are now being understood more clearly. We know that in the first phase of retinopathy of prematurity, hyperoxia inhibits vascular endothelial growth factor. In the second phase, vascular endothelial growth factor rises, and when insulin-like growth factor-1 reaches a threshold around 32 to 34 weeks post-conceptional age, uncontrolled neo-vascularization may occur.