Morphological Characteristics of the Optic Nerve Head and Choroidal Thickness in High Myopia

PURPOSE: This study aimed to explore the morphological characteristics of Bruch's membrane opening distance (BMOD), border length (BL), border tissue angle (BTA), vertical tilt angle, and peripapillary atrophy (PPA), as well as their associations with choroidal thickness (ChT) in young healthy highly myopic eyes. METHODS: A total of 167 patients with high myopia and 172 individuals without high myopia were enrolled. All of the subjects were divided by axial length. The PPA area was measured on fundus photographs. BMOD, BL, BTA, vertical tilt angle, macular ChT (mChT), and peripapillary ChT (pChT) were measured on swept-source optical coherence tomography scans. RESULTS: The PPA area (P < 0.0001) and vertical tilt angle (P < 0.0001) were larger, BMOD (P < 0.0001) and BL (P < 0.0001) were longer, and BTA (P < 0.0001) was smaller in the high-myopia group compared with the group without high myopia. Every 1-µm increase in BMOD was associated with a 35.80-µm decrease in mChT; every 1° decrease in BTA was correlated with a 0.32-µm decrease in mChT and a 0.26-µm decrease in pChT; and no association was found between PPA area and ChT in the multivariate linear regression model. CONCLUSIONS: PPA area, BL, BMOD, and vertical tilt angle increased, but BTA decreased with axial elongation of the globe in young, healthy patients with myopia. Longer BMOD was positively correlated with lower mChT, and smaller BTA was positively correlated with lower mChT and pChT in this population.