Swept-Source OCT Angiography-Derived Regional Normative Data of Peripapillary Vessel Density in Healthy Populations

The purpose of this study was to investigate the distribution of peripapillary vessel density (VD) across different regions of retinal and choroidal layers and analyze its influencing factors after axial length (AL) correction. This study included 337 eyes without significant fundus abnormalities or systemic conditions affecting blood flow. Swept-source optical coherence tomography angiography (SS-OCTA) was utilized to measure peripapillary VD and associated ocular parameters. VD in all regions of the choroidal layer decreased significantly with increasing AL among AL groups. In non-highly myopic eyes, VD followed the pattern temporal (T) > superior nasal (SN) > inferior nasal (IN) in the inner retina and superficial vascular complex (SVC), whereas in the deep vascular complex (DVC), it was inferior (I) > superior (S). In the choroid, VD ranked as nasal (N) > T. Highly myopic eyes showed higher temporal but lower nasal VD in the inner retina and SVC, whereas DVC exhibited the opposite trend. Choroidal VD decreased significantly across all regions, most prominently in the T hemisphere. Multivariable analysis identified age, signal strength, and retinal nerve fiber layer (RNFL) thickness as key determinants of inner retinal VD, whereas AL, signal strength, vertical cup-to-disc ratio (C/D), Bruch's membrane opening (BMO), and optic disc-fovea distance (DFD) significantly influenced choroidal VD. Inner retinal VD followed T > SN > IN, primarily contributed by the SVC, whereas choroidal VD followed N > T. With increasing AL, choroidal VD declined across all regions, most prominently in the T hemisphere, whereas the inner retinal VD trends varied by region and layer. The findings of this study may contribute to the early warning of the disease and provide an important theoretical basis for the study of myopia-related microcirculatory alteration mechanisms.