Purpose: To evaluate the risk factors in the development of mild and severe retinopathy of prematurity (ROP).
Methods: All infants (n = 88) screened for ROP at a neonatal intensive care unit over a 2-year period with gestational age <or=34 weeks and follow-up of 43 weeks postconception were included. The findings were classified in accordance with the International Classification of Retinopathy of Prematurity. The study group was classified into three subgroups: group A included patients without retinopathy; group B included patients with stage 1 or 2 (mild-ROP); and group C included patients who progressed to moderate or severe stage 3 (severe-ROP) and were treated. A retrospective review of records was performed and statistical analysis of eight possible risk factors for ROP was evaluated by using logistic regression.
Results: Logistic regression analysis showed birth weight (BW) (p=0.019) and respiratory distress syndrome (p = 0.029) as independent significant risk factors for the development of stage 1 and 2 ROP, with BW (p < 0.0001) as an independent significant risk factor for the progression to stage 3 ROP. Total volume of blood transfusion and duration of artificial ventilation were also found to be risk factors with high rates of stage 3 ROP. In group C, BW <or=1000 g (p = 0.0002) and gestational age <or=28 weeks (p < 0.0001) were significant risk factors associated with higher rates of ROP.
Conclusions: This study showed BW and respiratory distress syndrome as independent risk factors in the development of mild ROP and BW in the development of severe ROP.