Risk factors for severe retinopathy of prematurity in preterm low birth weight neonates

Objective: To evaluate the risk factors predisposing to severe retinopathy of prematurity (ROP) in a level III neonatal unit. This retrospective study was conducted in a tertiary care neonatal and ophthalmic center. Methods: The authors retrospectively analyzed data of preterm infants who were born from January 2003 through December 2008 and were screened for ROP. Data were collected from prospectively filled ROP screening forms. All the neonates with gestation ≤ 32 wks or birth weight ≤ 1500 g were screened. In addition, infants with birth weight of 1501-1800 g or gestation of 33-34 wks were also screened in the presence of additional risk factors like need for oxygen or mechanical ventilation. Primary outcome was severe ROP defined as treatable ROP as per type I ETROP guidelines (after year 2005) or threshold disease (before 2005). Results: A total of 704 neonates were screened during the study period, of whom 84 (11.9%) and 33 (4.7%) infants developed any ROP and severe ROP, respectively. The mean birth weight and gestation of infants with severe ROP were 1113 ± 438 g and 29 ± 3 wks, respectively. The following risk factors were found to be significant for severe ROP on univariate analysis: gestation ≤ 30 wks, birth weight < 1000 g, respiratory distress syndrome, use of surfactant, apnea, hypotension, patent ductus arteriosus (PDA), sepsis, necrotizing enterocolitis, pneumonia, meningitis, intraventricular hemorrhage, packed cell transfusion, and use of oxygen, continuous positive airway pressure and positive pressure ventilation. On multivariate analysis by stepwise logistic regression, respiratory distress syndrome (adjusted OR: 8.1 (95% CI 2.6-25.1); p < 0.001), PDA requiring medical or surgical management (adjusted OR: 3.2 (95% CI 1.1-8.9); p = 0.03), and meningitis (adjusted OR: 6.7 (95% CI 1.9-23.0); p = 0.002) were found to be independently associated with severe ROP. All infants with severe ROP had regression of the disease after laser therapy. Conclusions: Respiratory distress syndrome, PDA requiring medical or surgical management and meningitis were found to be associated with severe ROP. Outcomes were good after laser therapy with all followed-up infants having regression of the disease