PURPOSE: Preterm children have an increased risk of impaired vision from retinopathy, strabismus, and high refractive error. The aim of this study was to investigate the relationship between foveal parameters generated by optical coherence tomography angiography and visual function in preterm children. METHODS: Eighty eyes (32 eyes of former preterm infants and 48 age-matched full-term control eyes) were analyzed. Subjects underwent complete eye examinations including best-corrected visual acuity and retinal imaging with the Optovue XR Avanti optical coherence tomography angiography device. Foveal morphologic parameters including foveal depth, central foveal thickness, inner retinal area, and outer retinal area were measured on a central horizontal B-scan. Foveal vasculature parameters including foveal avascular zone, superficial capillary plexus-vessel density, and deep capillary plexus-vessel density were measured on optical coherence tomography angiography. RESULTS: The best-corrected visual acuity was significantly affected in preterm children compared with controls (P < 0.0001). The central foveal thickness (P < 0.0001), inner retinal area (P = 0.01), and outer retinal area (P = 0.03) were significantly increased in preterm compared with control eyes. Foveal depth (P < 0.001) and foveal avascular zone (P < 0.001) were significantly decreased in preterm compared with control eyes. The superficial capillary plexus-vessel density (P = 0.01) and deep capillary plexus-vessel density (P = 0.003) at the fovea (1 mm) were significantly increased in preterm compared with control eyes. The best-corrected visual acuity was negatively correlated with foveal depth (r = -0.42, P = 0.001) and foveal avascular zone (r = -0.53, P < 0.001), and positively correlated with central foveal thickness (r = 0.32, P = 0.01) and inner retinal area (r = 0.32, P = 0.01), indicating that worse visual acuity was associated with a smaller foveal avascular zone, shallower foveal depth, increased central foveal thickness, and larger inner retinal area. CONCLUSION: Foveal morphology and vasculature changes in preterm children were associated with impaired visual function. Further longitudinal studies are required to evaluate these changes over time.