Abstract
Abstract: :
Purpose: With improvement in cardio–pulmonary support of the very premature neonate, we have witness a rising incidence of aggressive zone I disease in the micro–preemie. Some also manifest a significant delayed of retinal vascular maturation and a new ROP variant of predominantly zone III dry and fibrotic traction, also known as smoldering ROP. In developing nations, the incidence of ROP is also on the rise but often differs in clinical features. We explore clinical aspects of ROP occurring in two disparate populations. Methods: Retrospective case–control study. We compared the clinical features and photographs of two consecutive series of 50 neonates who reached threshold ROP and were managed at two major pediatric retina referral centers, Childrens Hospital Los Angeles and The Aravind Eye Hospital of Coimbatore, India. We compared gestational age, birth weight, age at threshold, severity of plus, location and extent of neovascularization, ocular and systemic co–morbidities, need for surgical procedures including peripheral ablation and vitreo–retinal surgery, anatomic outcome, and qualitative features of the retinal vascular configuration as seen on RetCam imaging and fundus drawings. . Results:For preemies reaching threshold, the mean gestational age in Los Angeles was 24.5 weeks and mean birth weight was 766 grams, as opposed to 33.8 weeks and 1521 grams in Coimbatore. Threshold tended to occur around 37 weeks post conceptual age in both groups, with a mean post–natal age of 12 weeks in Los Angels group and 4 weeks in Coimbatore. Neonates in Southern California more often presented with zone 2 extra–retinal neovascularization or zone 1 flat neovascularization. Those in Southern India more often manifested plus disease with arterio–venous loops and shunts with capillary drop out but less severe neovascularization. They also tended to have less weight gain over the first 12 weeks of life, especially during the two weeks preceding the diagnosis of threshold. Both groups had patients requiring more than one procedure, with repeat laser occurring more often in the Coimbatore group and lens–sparing vitrectomy occurring more often in the Los Angeles group. Conclusions: We postulate that nutritional and genetic factors as well as neonatal intensive care unit practice patterns may account for part of this difference in ROP presentation.
Keywords: retinopathy of prematurity • retinal development • retinal neovascularization