Incidence and risk factors of retinopathy of prematurity in a tertiary care newborn unit in New Delhi.

Background: Retinopathy of prematurity (RoP) has become more common in developed countries with an improvement in survival of very premature infants. Though previously rare, it is likely to emerge as a major problem in India because of improving outcome of 'at-risk' preterm infants.
Methods: In a prospective study we estimated the incidence of RoP among at-risk neonates in a tertiary care unit. Infants with birth-weights of < 1500 g, gestation < 35 weeks and preterm neonates who required supplemental oxygen for > 24 hours were subjected to periodic ophthalmological evaluation for detection of RoP until full retinal vascularization occurred.
Results: Sixty-six eligible infants completed the full protocol during the 15-month study period. The incidence of RoP was 20% in the cohort and 27% among the very low birth-weight neonates. The incidence of threshold RoP was 7% in the cohort. The occurrence of RoP was inversely related to the gestation and birth-weight. RoP typically developed at the post-conceptional age of 32-35 weeks. Blood transfusion and clinical sepsis emerged as independent risk factors of RoP on step-wise logistic regression analysis. Cryotherapy undertaken in 5 cases (9 eyes) led to amelioration of the changes of RoP.
Conclusion: The incidence of RoP in our neonates was lower than that reported from other centres. Blood transfusion and clinical sepsis are risk factors for RoP in our newborn infants.