RESUMEN
OBJECTIVE: The objective of this study was to determine the potential risk factors in acute retinopathy of prematurity (ROP). PATIENTS AND METHODS: A retrospective study of preterm infants with birth weights less than 1,501 g, or more if mechanical ventilation and oxygen administration were needed, was carried out. Indirect ophthalmoscopy (mydriasis) with indentation was done every 15 days from the fourth week. Fifteen factors were analyzed. Statistically significant differences between the groups with and without ROP were sought with Fisher's exact probability test, two-sample t-test, and the chi-square contingency-table. A logistic regression was done. RESULTS: Thirty-six of the 137 infants examined (26.2%) with birth weight < or = 1,500 g had acute ROP. Only 7.1% of the infants with birth weights > or = 1,501 g had retinopathy. There were significant differences (p < 0.05) in the following variables: birth weight, gestational age, blood transfusion, mechanical ventilation, FiO2 (fraction inspired oxygen) maximum, time of FiO2 > or = 0.60 (hours) and time of FiO2 > or = 0.21 (days). However, the birth-weight was the only independent risk factor related to ROP. CONCLUSIONS: Retinopathy of the premature has a multifactorial etiology. The low gestational age and the oxygen had influence on ROP; however, low birth weight was the independent risk factor.
