LAUSR

PURPOSE To use optical coherence tomography (OCT) to 3D characterize optic nerve head (ONH) peripapillary scleral bowing in non-highly myopic healthy eyes. DESIGN Cross-sectional, multicenter study. METHODS 362 non-highly myopic (+6 diopters (D) > spherical equivalent > -6D) eyes of 362 healthy subjects aging from 20-90 years underwent OCT ONH radial B-scan imaging. Bruch's membrane (BM), BM opening (BMO), ASCO and the peripapillary scleral surface were segmented. BMO and ASCO planes were fit and their centroids, major axes, ovality, area and offset were determined. Peripapillary scleral bowing was characterized by two parameters: peripapillary scleral slope (ppSS) of three anterior peripapillary scleral segments (0-300, 300-700 and 700-1000 μm from the ASCO centroid); and ASCO depth relative to a peripapillary scleral reference plane (ASCOD-ppScleral). Peripapillary choroidal thickness (ppCT) was calculated relative to the ASCO as the minimum distance between the anterior scleral surface and BM. RESULTS ppSS and ASCOD-ppScleral both ranged from slightly inward through profoundly outward in direction. Both parameters increased with age and were independently associated with decreased ppCT. CONCLUSIONS In non-highly myopic healthy eyes outward peripapillary scleral bowing achieved substantial levels, was markedly increased with age and was independently associated with decreased peripapillary choroidal thickness. Our findings provide a normative foundation for characterizing this anatomy in high myopia and glaucoma and in eyes with optic disc tilt, torsion and peripapillary atrophy.