Trends in Retinopathy of Prematurity and Strabismus Among Preterm and Low-Birth-Weight Infants in Korea: A Nationwide Population-Based Study

Background/Objectives: In Korea, the proportion of preterm and low-birth-weight infants has risen even as total births have fallen, changing the population at risk for eye disease of prematurity. Whether nationwide trends in retinopathy of prematurity (ROP) and strabismus reflect true temporal change or the shifting composition of this high-risk birth cohort is unclear. We examined 13-year trends in both conditions and assessed whether they persisted after adjustment for major risk factors.

Methods

We analyzed nationwide Health Insurance Review and Assessment Service claims from 2010 to 2022. Infants born at a gestational age below 37 weeks and/or with a birth weight below 2500 g were included. ROP and strabismus were identified from diagnostic codes, and gestational age and birth weight strata from perinatal diagnosis codes. Multivariable logistic regression estimated adjusted odds ratios for calendar-year trends and for joint gestational age and birth weight subgroups.