RECENT TRENDS IN THE CUMULATIVE INCIDENCE AND INTERVENTION PATTERNS OF RETINOPATHY OF PREMATURITY IN JAPAN: A Multicenter Analysis, 2011-2020.

Purpose: To investigate recent trends in the cumulative incidence and treatment patterns of retinopathy of prematurity (ROP) in Japan.

Methods: A retrospective multicenter cohort was conducted from 2011 to 2020 using the Diagnosis Procedure Combination inpatient database. Preterm newborns with birth weight <2,500 g were categorized by birth weight. The cumulative incidence of ROP, treatment patterns, and association between treatment and birth weight were investigated.

Results: A total of 82,683 preterm infants were identified, of whom 9,335 (11.3%) were diagnosed with ROP. The cumulative incidence of ROP increased by 15% in those with birth weight <500 g over the study period. Among the ROP infants, 20.2% received treatment, including laser photocoagulation (94.8%), intravitreal injection (3.8%), or both (1.8%). The proportion receiving laser photocoagulation decreased followed by an increase in intravitreal injection. This shift in intervention pattern was most conspicuous for those with birth weight 750 to 1,249 g. The risk ratio of receiving laser and intravitreal injection for those weighing <500 g was 24.7 (95% confidence interval, 10.5-58.2) and 28.4 (5.8-138.1), respectively, as compared with infants weighing >1,500 g.

Conclusion: The cumulative incidence of ROP increased in infants with birth weight <500 g. A shift from laser photocoagulation to intravitreal injection was observed in the more recent years.