Association of various postnatal risk factors with progression of retinopathy of prematurity (ROP) in preterm neonates: A case-control study.

Retinopathy of prematurity (ROP) is a complex disease of the developing retinal vasculature in infants born prematurely and is the leading preventable cause of childhood blindness worldwide. Multiple factors play a significant role in the pathogenesis of this disease.

Aim: Our study aimed to determine and analyze various postnatal risk factors involved in the development and progression of ROP amongst preterm neonates.

Methods: This case-control ambispective study was conducted at a single tertiary care hospital between 01-01-2019 and 31-07-2023. A total of 112 eyes (56 preterm neonates) were included after considering the various risk factors. The selected neonates were then followed up in the NICU (if admitted)/OPD (if discharged) of the Pediatrics and Ophthalmology Department.

Results: Out of 112 eyes screened, 98 (87.5%) were included after excluding babies who died/were lost to follow-up/had severe systemic disease. Among the 98 eyes included, 18 (18.3%) had no ROP, whereas 80 (81.6%) developed ROP. Cases (26 eyes) were selected from among the patients in whom ROP developed which progressed to require intervention, whereas controls (54 eyes) - after matching were those babies who developed ROP but in whom ROP regressed. These were then retrospectively studied for various prenatal and postnatal risk factors. Among the prenatal risk factors gestational age and birth weight and amongst postnatal- oxygen therapy, CPAP, mechanical ventilation, RDS, sepsis, surfactant, blood transfusion, and PDA were found to be significant in cases in comparison to control, so these factors were found responsible for development and progression of ROP- as described in various other studies, whereas neonatal hyperbilirubinemia and intraventricular hemorrhage were found to be insignificant. However, when the primary objective was being studied, we observed that ROP regressed in good weight gain babies, i.e. ≥14 g/day (in 54 eyes - 55.1%), whereas those babies with poor weight gain ≤14 g/day, it progressed to severe form requiring treatment (26 eyes - 26.5%) out of which 4 eyes (5%) had AROP, 2 eyes (2.5%) had Zone 2 posterior stage 2 ROP, 6 eyes (7.5%) had Zone 2 anterior Stage 2 ROP 11 eyes (13.7%) had Stage 3 ROP, 3 eyes (3.7%) had Stage 4A ROP, and no patients progressed to Stage 5 ROP.

Conclusion: Our study revealed a positive correlation between various risk factors and the development and progression of ROP. Oxygen therapy has a vivid proven role in the development of ROP. However, for progression we observed a significant relationship between weight gain/day and ROP regression, suggesting that pediatricians should aggressively work toward rapid weight gain in preterm neonates while reducing the duration and therapeutic exposure of oxygen to the greatest extent possible.