Anemia of Prematurity - Portal Neonatal

Retinopathy of Prematurity
Last Updated: October 29, 2002
Synonyms and related keywords: ROP, retrolental fibroplasia, retinal neovascularization
AUTHOR INFORMATION Section 1 of 10
Author: Rosemary Higgins, MD, Codirector, Neonatal Perinatal Medicine Fellowship Program,
Associate Professor, Department of Pediatrics, Division of Neonatology, Georgetown University
and Children's Medical Center
Rosemary Higgins, MD, is a member of the following medical societies: Society for Pediatric
Research
Editor(s): Oussama Itani, MD, Medical Director of Neonatology, Borgess Medical Center,
Clinical Assistant Professor, Department of Pediatrics and Human Development, Michigan
State University; Robert Konop, PharmD, Director, Clinical Account Management, Ancillary
Care Management; Arun Pramanik, MD, Professor, Department of Pediatrics, Division of
Neonatology, Louisiana State University Health Science Center; Carol L Wagner, MD,
Associate Professor, Department of Pediatrics, Division of Neonatology, Medical University of
South Carolina; and Neil N Finer, MD, Director, Division of Neonatology, Professor,
Department of Pediatrics, University of California at San Diego
INTRODUCTION Section 2 of 10
Background: Retinopathy of prematurity (ROP) is a serious vasoproliferative disorder affecting
extremely premature infants. ROP often regresses or heals, but it can lead to severe visual
impairment or blindness. Significant ROP can lead to lifelong disabilities for the smallest
survivors of neonatal intensive care units. ROP remains a serious problem despite striking
advances in neonatology.
Pathophysiology: ROP primarily occurs in extremely low birth weight (ELBW) infants. Most
research suggests that a low birth weight, a young gestational age (GA), and the severity of the
illness (eg, days the patient receives supplemental oxygen) are associated factors. Recently,
other associations have been described. However, the severity of the illness appears to be a
major predictor of severe disease. The smallest, sickest, and most immature infants are at the
highest risk for serious disease. African American infants appear to have less severe ROP.
Retinal vasculature begins to develop around the 16th week of gestation. It grows
circumferentially and becomes fully mature at term. Premature birth results in the cessation of
normal retinal vascular maturation. Blood vessels constrict and can become obliterated,
resulting in delays of normal retinal vascular development. Early on, oxygen and nutrients can
be delivered to the retina by means of diffusion from the underlying choroid. The retina
continues to grow in thickness and eventually outgrows its vascular supply. Over time, retinal
hypoxia occurs and results in an overgrowth of vessels. This process is mediated in part by
vascular endothelial growth factor (VEGF). These problems result in ROP.
Frequency:
• In the US: The incidence varies with birth weight, but it is reported to be approximately
50-70% in infants whose weight is less than 1250 g at birth.
Hussain et al reviewed the incidence and the need for surgery in neonates with ROP
who were born at 22-36 weeks' GA between July 1989 and June 30, 1997. The
incidences were 21.3% (202 of 950) for ROP of any stage and 4.6% (44 of 950) for
ROP at stage 3 or worse. No ROP was noted in infants born after 32 weeks' GA. No