Prevalence and Risk Factors of Retinopathy of Prematurity in Very Low Birth Weight or Low Gestational Age Infants

To determine the incidence of retinopathy of prematurity (ROP) and to evaluate the possible neonatal risk factors for ROP. This cross-sectional study included all premature infants born at hospitals affiliated to Tehran Medical University, Tehran-Iran who were referred within 4-6 weeks after delivery to Farabi Eye Hospital from 2004 to 2005. Inclusion criteria were birth weight (BW) < 1500 g or gestational age (GA) ≤ 32 weeks. One-hundred and forty-seven infants (74 male, 73 female) were included in this study. ROP was present in 44 (29.9%) newborns (8.8% in prethreshold and 21.1% in threshold stage). Mean GA was 30.30±2.33 wk and mean BW was 1385.82±355.91 g. A significant association existed between the incidence of ROP and low gestational age (P< 0.001), low birth weight (P< 0.001), oxygen therapy (P= 0.033), bronchopulmonary dysplasia (P= 0.001), respiratory distress syndrome (P= 0.00 1) and blood transfusion (P= 0.013). There was no significant association between ROP and sex, multiple gestations, mechanical ventilation, intraventricular hemorrhage, sepsis and phototherapy. In multivariate logistic regression analysis, only gestational age (P=0.002), bronchopulmonary dysplasia (P=0.006) and phototherapy (P=0.031) remained significant risk factors for ROP. The incidence of ROP in this study is higher than previous studies in our center. This may be due to advances in Neonatal Intensive Care Unit equipment and surveillance. Suitable criteria for ROP screening seem to be GA < 32 wk or BW < 1500 g. Newborns with 1500 g < BW < 2000 g or GA> 32 wk who may be at high risk for ROP should also be screened.