The Incidence and Timing of Treatment-Requiring Retinopathy of Prematurity in Nanopremature and Micropremature Infants in the United States: A National Multicenter Retrospective Cohort Study

Participants: This article includes 7293 infants (14 586 eyes) screened for ROP across 5 centers in the United States (Austin Retina Associates, Austin, TX; Bascom Palmer Eye Institute, Miami, FL; Beaumont Eye Institute, Royal Oak, MI; Massachusetts Eye and Ear, Boston, MA; and Stanford Byers Eye Institute, Stanford, CA). Purpose: To analyze the incidence and timing of treatment requiring retinopathy of prematurity (ROP) in extremely small premature infants. We hypothesize that the smaller the infant by gestational age and birthweight, the higher their likelihood of requiring treatment for ROP. Design: Premature infants screened for Retinopathy of Prematurity from 2002-2022 were divided into cohorts based on the following criteria based on gestational age (GA) and birth weight (BW). “Micropremature infants” are infants born between 24-26 weeks GA and between 600-799 g BW. “Nanopremature infants” are born ≤ 24 weeks GA and ≤ 600 g BW. Methods: Retrospective chart review. Main Outcome Measures: The incidence and timing of treatment-requiring ROP. Results: We found that infants defined as nanopremature had a ∼63% chance of requiring treatment at an average postmenstrual age (PMA) of 36.6 weeks, whereas those defined as micropremature had a 30% chance of requiring treatment at an average PMA of 36.3 weeks. This significantly contrasts with the risk of all screened babies for ROP where the risk of requiring treatment was 8.5%. Conclusion: Micropremature and nanopremature infants are significantly more likely to require treatment for ROP. With demographic data matched to all 5 major US regions spanning the last decade, these results have the potential to inform neonatologists, pediatricians, and ophthalmologists of an important shift in the landscape of prematurity in the United States. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.