High burden of treatment-requiring retinopathy of prematurity in Kathmandu, Nepal: a prospective multicentre observational study

Background: Retinopathy of prematurity (ROP) is an important cause of avoidable childhood blindness in low- and middle-income countries, where increasing survival of preterm infants has outpaced improvements in neonatal care. We assessed the frequency, severity and treatment requirements of ROP across neonatal intensive care units (NICUs) and specialist eye centres in the Kathmandu Valley. Methods: This prospective multi-centre observational cohort study was conducted from February–November 2025 at two level III NICUs and two tertiary eye centres in Kathmandu. Preterm infants with a gestational age (GA) <34 weeks and/or a birth weight (BW) <2000 g, and infants of 34–36 weeks GA with risk factors, were enrolled. Bilateral wide-field retinal imaging was performed at serial examinations and ROP was classified according to ICROP-3. The primary outcome was development of type 1 ROP. Baseline characteristics were compared between infants who developed type 1 ROP and those with type 2 ROP or no ROP using t-tests and chi-square tests, with odds ratios (OR) and 95% confidence intervals (CI) for factors estimated for prespecified factors associated with type 1 ROP. Results: Of 222 infants who underwent at least one ROP examination, 208 completed follow-up to complete retinal vascularisation or disease resolution. Among these 208 infants, 76 (36.5%) developed ROP, including 46 (22.1%) with type 1 ROP and 30 (14.4%) with type 2 ROP. Aggressive posterior ROP (A-ROP) occurred in 14 (6.7%) infants. Infants who developed type 1 ROP had lower mean GA and BW than those with type 2 ROP or no ROP. BW ≤1500 g was associated with type 1 ROP (OR 2.99, 95% CI 1.73–5.18). Type 1 ROP was more frequently observed among infants screened at specialist eye centres than NICUs (OR 3.12, 95% CI 1.67–5.80), although this comparison may reflect referral selection. ROP was present at the first examination in 60 of 222 infants (27.0%). 3/25 infants (12.0%) outside the principal enrollment thresholds developed ROP, including 1/25 (4.0%) with type 1 ROP. Conclusions: ROP, including Type 1 disease, was frequently observed, with some cases detected at the initial screening and among infants beyond conventional eligibility criteria, underscoring the need for Nepal-specific screening guidelines and strengthened referral pathways. Trial registration: Registered as https://www.isrctn.com/ISRCTN62477762on the date 02/11/2025