Retinopathy of prematurity, frequency and risk factors in very low birth weight infants

Background: Retinopathy of prematurity (ROP) is the principal cause of blindness during childhood. The objective of this study was to analyze the frequency of ROP and risk factors associated with ROP in a cohort of very low birth weight infants. Methods: A cases (ROP) and controls (no ROP) study of infants less than 1500 g was conducted. Perinatal and neonatal variables were analyzed. For the statistical analysis, chi(2) test, Student's t-test and Mann-Whitney's U-test were used. Results: For the study, 282 neonates were included: 152 (53.9%) with ROP and 130 (46.1%) without ROP. The most frequent stages observed were stage 1 and 2, with 139 (91.4%) patients, and stages 3 to 5, with only 13 patients (8.5%). In those neonates with ROP compared with neonates without ROP, the birth weight was less (902.7 vs. 1037.9 g) and the difference was significant (p < 0.0001). Also, the difference with gestational age (28.2 vs. 29.6; p < 0.0001), total ventilation days (32.8 vs. 16.1; p < 0.00001) and total oxygen days (87.7 vs. 62.6; p < 0.0001) was significant in neonates with ROP and neonates without the disease. Bronchopulmonary dysplasia, intraventricular hemorrhage and late onset sepsis were significant with patients with ROP. Conclusions: The frequency of ROP reported here is higher than the reported in Mexican population, with less cases of severe ROP. The neonatal surveillance in babies with less birth weight and gestational age is important to decrease the incidence of ROP.