Clinical characteristics and treatment response of treatment requiring retinopathy of prematurity (ROP) in Big Premature Infants in Turkiye: BIG-ROP Study Group Report No 2 (BIG-ROP STUDY).

Objective: This study evaluated the clinical characteristics and treatment outcomes of bigger premature infants treated for retinopathy of prematurity (ROP).

Methods: A retrospective, multicentre study analysed data from 33 ROP centres in Türkiye. Infants with gestational ages (GA) of 32-37 weeks and birth weights (BW) >1500 g who required ROP treatment were included. Patient demographics, clinical details, treatments, responses and complications were recorded. Descriptive statistics were calculated after excluding cases with missing or erroneous data.

Results: The study included 365 eyes of 365 infants. The average GA at birth was 33±1 weeks, with a mean BW of 1896±316 g. Of these, 83.6% had type 1 ROP, and 16.4% had aggressive ROP (A-ROP). Treatment-requiring ROP (TR-ROP) occurred at an average postmenstrual age of 39.0±4.6 weeks. Among 170 infants with TR-ROP at their first exam, 81.2% were screened at 4 weeks postpartum. Reactivation of ROP was observed in 5.4% of the primary laser photocoagulation (LPC) group and 23.9% of the primary anti-vascular endothelial growth factor (VEGF) group (p<0.001). Reactivation and progression to stage 4-5 were more frequent in A-ROP cases (p=0.012; p=0.008). The need for additional treatment was significantly higher in cases of A-ROP, zone 1 disease or stage 4-5 disease (p<0.001). Anti-VEGF therapy demonstrated superior single-treatment success rates in A-ROP eyes compared with laser LPC (85.7% vs 60%, p=0.03). Infants requiring additional treatments also had higher rates of respiratory distress syndrome (RDS), maternal premature rupture of membranes (PROM) and non-ophthalmological surgical interventions (p<0.05).

Conclusion: Bigger premature infants in low and middle-income countries should be screened earlier than 4 weeks after birth. A-ROP, zone 1 disease and stage 4-5 disease have higher reactivation risks. Primary anti-VEGF therapy was associated with a greater need for retreatment. Maternal PROM, RDS and surgical interventions also increase retreatment risk. Limitations include retrospective design and lack of smaller preterm comparisons, potentially limiting generalisability.