Prevalence and risk factors of retinopathy of prematurity

Background Retinopathy of prematurity (ROP) is the main cause of visual impairment in premature infants. Due to advances in neonatal care, the increased survival of extremely low birth weight (ELBW) infants in recent years has produced a population of infants at very high risk of ROP. Objective The aims of this study were to determine the prevalence and potential risk factors for ROP. Methods This retrospective study was conducted at the Neonatalogy Ward, Cipto Mangunkusumo Hospital, from January 2005 to August 2010. We included all premature infants of gestational age (GA) < 37 weeks, body weight (BW) not exceeding 2000 grams, as well as those who had eye examinations and complete medical records. Risk factors such as GA, BW, duration of oxygen (02) therapy, sepsis, and red blood cell (RBC) transfusion were analyzed using the Chi-square and logistic regression tests. Pediatric ophthalmologists had performed eye examinations on all infants. ROP was graded according to the International Classification of ROE. Results The prevalence of ROP and of stage 3 or greater ROP WAS 11.9% and 4.8% of all subjects, respectively. Body weight, GA, duration of O-2 therapy, and sepsis were found to be associated with the development of ROP. However, stepwise logistic regression analysis revealed that only BW of <= 1000 g [odds ratio (OR) 10.88; 950 CI 3,09 to 38.31; P < 0.000], O2 therapy >=. 7 days (OR 5.56; 95% CI 1.86 to 16.58; P = 0.0001), and GA of 5 28 weeks (OR 4.26; 95% CI 1.15 to 15.81; P = 0.030) were statistically significant risk factors for ROP. The equation obtained was y = -4.092 + 2.388 (BW) + 1.451 (GA) + 1.716 (duration of O2 therapy). The model showed good calibration (a non-significant Hosmer-Lemeshow test; P = 0.816) and discriminative ability. The area under the curve (AUC) value was 92.2% (95% CI 0.867 to 0.976; P < 0.0001. Conclusion Prevalence of ROP in this study (11.9%) was lower than that of previous studies. By regression logistic analysis, the main risk factors for development of ROP were BW of <= 1000 g, O-2 therapy >= 7 days, and GA <= 28 weeks. The probability of' ROP occurrence increased with greater number of risk factors.