Deep Optic Nerve Head Structures Associated With Increasing Axial Length in Healthy Myopic Eyes of Moderate Axial Length

Abstract

<p>PURPOSE: To elucidate which swept-source optical co-herence tomography (OCT)-derived optic nerve head (ONH) parameters are associated with longer axial length (AXL) in healthy myopic eyes. center dot DESIGN: Prospective cross-sectional observational study. center dot METHODS: Two hundred eleven healthy eyes of 140 participants (96 emmetropic-mild myopic [AXL: 22.2-24.5 mm], 83 moderately myopic [24.5-26.0 mm], and 32 highly myopic [26.0-27.4 mm] eyes) were en-rolled. Bruch membrane opening (BMO), anterior scle-ral canal opening (ASCO) area and ovality, minimum rim width, parameters defining misalignment between the BMO and ASCO planes, OCT-defined region of per-ineural canal retinal epithelium atrophy and externally oblique choroidal border tissue, circumpapillary retinal nerve fiber layer thickness (cpRNFLT), circumpapillary choroidal thickness (cpChT), lamina cribrosa parame-ters, and peripapillary scleral (PPS) angle were calculated from BMO-centered radial scans reconstructed from 3D raster scans. Multivariate linear mixed models were used to elucidate ONH parameters that are independently as-sociated with AXL. center dot RESULTS: Longer AXL was associated with a greater misalignment between ASCO and BMO planes, larger re-gion of externally oblique choroidal border tissue, thinner cpChT, larger PPS angle, larger ASCO area, and thicker cpRNFLT (all P < .040 after Bonferroni's correction for number of included explanatory variables). center dot CONCLUSIONS: A greater misalignment between BMO and ASCO planes, thinner choroid, a more posteriorly bowed PPS, an enlargement of ASCO, and thicker cpRN-FLT were each associated with longer AXL. An en-hanced understanding of these AXL-associated configu-rations should provide essential information to improve our ability to detect glaucoma-induced ONH morphology in myopic eyes. (Am J Ophthalmol 2023;249: 156-166.<br></p>