[Prevalence of retinopathy of prematurity in premature babies examined during the period 1992-1999, Joinville (SC): evaluation of associated risks--screening]

Abstract

Purposes: To evaluate the prevalence of retinopathy of prematurity in premature babies examined at the "Hospital de Olhos Sadalla Amin Ghanem", coming from the "Maternidade Darcy Vargas" during the period from June 1992 to June 1999. To describe the risk factors that cause a predisposition to develop retinopathy of prematurity in the "Maternidade Darcy Vargas" and criteria to improve screening.

Methods: 286 premature babies were selected in accordance with the predetermined criteria (gestation period less than 37 weeks, first examination at 4-12 week of age, minimum of 3 ophthalmic examinations before being 180 days old and registration at the "Hospital de Olhos Sadalla Amin"). An analysis of the total group of premature babies was carried out, being classified into Group 1 (without retinopathy of prematurity) and Group 2 (with retinopathy of prematurity) and the factors related to presence or not of retinopathy of prematurity in the premature babies were described. In order to evaluate the frequency of retinopathy of prematurity and factors associated with its occurrence, the Chi-Squared or the Fisher Exact tests were used. Margin of error 5%.

Results: 228 premature babies did not present sings of retinopathy of prematurity (group 1) and 58 presented signs (group 2). The prevalence of retinopathy of prematurity was 20%, 9% being in stage 1; 7% in stage 2; 4% in stage 3 and 1% in stage 4a. The most involved factors were: birth weight (p<0.0001), oxygen therapy (p<0.0000), birth age (p=0.0006), lung disease (p=0.0041), blood transfusion (p=0.0002), central nervous system alterations (p=0.0259), serious infections (p=0.0278) and Apgar less than 7 in the first minute (p=0.0442). The premature babies that most needed treatment weighed less than 1,399 g and were 33 weeks old.

Conclusion: According to the data the prevalence of retinopathy of prematurity was 20%. The premature babies' risks of retinopathy of prematurity were concentrated on weight below 1,400 g and age of 33 weeks. Bigger premature babies should be observed when one or more of the following factors are present: oxygen therapy, blood transfusion, lung disease, central nervous system alterations, serious infections and Apgar less than 7 in the first minute.