Current incidence of retinopathy of prematurity, 1989-1997

Objective. To report the current incidence and the need for surgery for retinopathy of prematurity (ROP) in neonates (22-36 weeks' gestational age [GA], July 1, 1989 through June 30, 1997). Study Design. Retrospective analyses using computerized perinatal database kept on all admissions, a review of patient charts, and eye examination log books. Setting. Level 3 regional referral NICU. Patients. A total of 2528 infants <37 weeks' GA were admitted during this time. Of these infants, 950 met the criteria for eye examination beginning at 4 to 6 weeks of age and repeated every 2 weeks until complete vascularization of the retina or death or discharge. Results. The incidence of ROP was (202/950) 21.3% for any stage and 4.6% (44/950) for stage 3 ROP or greater. No ROP was noted in infants born at >32 weeks' GA. No infant born at >28 weeks needed retinal surgery. Using birth weight (BW) criteria, stage 3 ROP was not noted in infants with BWs >1500 g; retinal surgery was not needed in infants with BWs >1000 g. A number of perinatal factors were associated with ROP on univariate analysis. However, using multiple logistic regression analyses of these factors, only GA and days on supplemental oxygen therapy were associated significantly with the development of ROP. Despite increased survival of extremely low BW infants, we found a considerable reduction in incidence and severity of ROP compared with reports from an earlier chronological period. However, infants <28 weeks' GA or with BWs <1000 g were still at considerable risk for retinal surgical treatment for ROP. Conclusion. We conclude that the incidence and severity of ROP have decreased significantly in the present era of surfactant therapy.