Risk Factors and Structural Impact of Macular Edema in Preterm Infants: An OCT-Based Cohort Study

Purpose: To investigate risk factors for macular edema (ME) and its impact on foveal development in preterm infants using handheld optical coherence tomography (OCT) and clinical data. Methods: This retrospective cohort included 106 preterm infants who underwent routine retinopathy of prematurity screening with RetCam 3 and OCT. Clinical variables were collected from records. ME was classified by OCT morphology. Quantitative foveal parameters-central foveal thickness (CFT), foveal inner retinal thickness (FIRT), foveal outer retinal thickness (FORT), mean parafoveal thickness (MPFT), mean parafoveal inner retinal thickness (MPIRT), foveal depth (FD), and foveal angle (FA)-were measured. Logistic regression identified ME risk factors, and linear and mixed-effects models assessed structural impact. Results: Of 106 infants, 27 developed ME (25.5%), and 79 served as controls (74.5%). Infants with resolved ME showed persistent abnormalities, including increased CFT (β = 43.40, P < 0.001), FORT (β = 27.67, P < 0.001), MPFT (β = 109.91, P < 0.001), and FA (β = 20.82, P < 0.001). MPIRT was also increased (β = 58.70, P = 0.002), whereas FD and FIRT did not differ significantly. Independent risk factors for ME included higher postmenstrual age at OCT, longer phototherapy, respiratory support, and moderate-to-high nutritional risk. Birth weight, gestational age, and Apgar scores were not significant predictors. Conclusions: ME in preterm infants is associated with persistent foveal abnormalities despite apparent resolution on OCT. Its development is more closely related to postnatal systemic factors-including nutrition, respiratory support, and phototherapy-than to perinatal indices, supporting risk-based OCT monitoring and longer follow-up.