Effects of Blood Transfusion on Retinopathy of Prematurity

Abstract

Retinopathy of prematurity (ROP) is a vasoproliferative retinal disorder, which represents the main cause of visual impairment and blindness in preterm infants (Drack,1998).ROP develops in 84% of premature survivors born at <28 weeks of gestation (Palmer et al,1991). Fortunately, it resolves in most cases (80%) without visual loss from retinal detachment or scars (Palmer et al, 1991; Cryotherapy for retinopathy of prematurity cooperative group, 1994). In this study, the total ROP incidence was 0.17% overall and 15.58% for premature infants with length of stay of more than 28 days (Lad et al, 2009). The increased survival of very small premature infants has led to the resurgence of this potentially blinding disease (Kinsey et al 1977; Shohat et al 1983)The pathogenesis of ROP isn’t fully known. The altered regulation of vascular endothelial growth factor from reported episodes of hyperoxia and hypoxia is an important factor in the pathogenesis of ROP (Chow et al 2003). Apparently, any severe physiologic stress may damage the developing capillaries in immature retina and in response to ischemia, new vessel (neovascular) growth resumes (Phelps, 1992).ROP appears to be a multifactorial disease. Given the multifactorial nature of ROP and close relation of the most risk factors to prematurity, it is difficult to define the specific role of any individual factor in the pathogenesis of ROP (Hesse et al 1997).