New findings on choroidal features in healthy people by ultra-widefield swept-source optical coherence tomography angiography.

To evaluate the distribution of choroidal thickness (CT) and its trend with age in healthy people using 120° ultra-wide field swept-source optical coherence tomography angiography (UWF SS-OCTA). In this cross-sectional observational study, healthy volunteers underwent single imaging of the fundus with UWF SS-OCTA at a field of view (FOV) of 120° (24 mm × 20 mm) centered on the macula. The characteristics of CT distribution in different regions and its changes with age were analyzed. A total of 128 volunteers with a mean age of 34.9 ± 20.1 years and 210 eyes were enrolled in the study. The thickest mean choroid thickness (MCT) was located at the macular region and supratemporal region, followed by the nasal side of the optic disc, and thinnest below the optic disc. The maximum MCT was: 213.40 ± 36.65 μm for the group aged 20-29, and the minimum MCT was: 162.11 ± 31.96 μm for the group aged ≥ 60. After the age of 50, MCT was significantly and negatively correlated decreased with age (r = - 0.358, p = 0.002), and the MCT in the macular region decreased more remarkably compared to other regions. The 120° UWF SS-OCTA can observe the distribution of choroidal thickness in the range of 24 mm × 20 mm and its variation with age. It was revealed that MCT decreased more rapidly in the macular region relative to other regions after 50 years old.