Incidence of retinopathy of prematurity among infants weighing 2000 g or less at birth.

A retrospective study was carried out to determine the incidence of retinopathy of prematurity (ROP) among 157 neonates who weighed 2000 g or less at birth and who were examined at a referral centre for critically ill newborns between January 1983 and December 1985. Overall, 24 cases (15%) of ROP were detected, 18 (75%) among neonates with a birth weight of 1000 g or less. The incidence of ROP was more than eight times higher among neonates in this birth weight category than among those who weighed between 1001 and 2000 g. Grade I ROP accounted for 16 cases (67%), grade II for 7 cases (29%). Only one case (4%) of grade IV ROP was diagnosed, in an infant who weighed 1020 g at birth.