Macular development in preterm twins with and without retinopathy of prematurity: an OCT angiography study from the Shenzhen prematurity eye study

PURPOSE: To evaluate the macular microvascular and structural characteristics in preterm twins aged 3 to 12 years using optical coherence tomography angiography (OCTA), and to investigate the impact of perinatal factors, including gestational age (GA), birth weight (BW), and birth order, on macular development and visual function. METHODS: This retrospective cohort study included 50 preterm twins (25 pairs, 98 eyes) followed at Shenzhen Eye Hospital from 2018 to 2023. All participants underwent OCTA and visual acuity examination. OCTA parameters and best-corrected visual acuity (BCVA) were compared between groups stratified by BW and birth order. Generalized estimating equation (GEE) models were used for statistical analysis. Univariable and multivariable analyses were used for retinopathy of prematurity (ROP) risk factor analyses and for association analyses of perinatal and OCTA parameters with BCVA and foveal avascular zone (FAZ) area. RESULTS: ROP was diagnosed in 24 of 50 preterm twins (48%). No significant differences were found in OCTA parameters and BCVA between two BW groups and between birth-order groups. In multivariable analysis, cesarean section was associated with a lower risk of ROP than vaginal delivery (OR = 0.049, P = 0.005). Lower GA was independently associated with worse BCVA (P = 0.03) and a smaller FAZ area (P < 0.01). CONCLUSION: BW and birth order had no significant effects on macular or visual development. Lower GA was associated with smaller FAZ area and poorer visual acuity in preterm twins.