Longitudinal Changes of Optic Nerve Head and Peripapillary Structure during Childhood Myopia Progression on OCT: Boramae Myopia Cohort Study Report 1

Abstract

Purpose: To delineate longitudinal changes in the optic nerve head (ONH) and peripapillary structure during myopia progression in childhood using spectral-domain (SD) OCT and to explore the factors associated with myopic ONH and peripapillary changes.

Design: Prospective cohort study.

Participants: Twenty-three healthy children with myopia (46 eyes).

Methods: The participants underwent fundus photography, SD OCT, and axial length (AXL) measurements every 6 months for 2 years. Based on the morphologic changes of the ONH and β-zone parapapillary atrophy (PPA), eyes were classified as group A (ONH unchanged without β-zone PPA; 11 eyes), group B (ONH changed without β-zone PPA at baseline; 10 eyes), group C (ONH changed with β-zone PPA at baseline; 15 eyes), and group D (ONH unchanged with β-zone PPA; 10 eyes). The configuration of the border tissue (BT) at the temporal margin of the ONH was assessed, and the ONH parameters, including Bruch's membrane opening distance (BMOD), border length (BL), and BT angle (BTA), were measured on horizontal SD OCT scans.

Main outcome measures: Changes in ONH parameters and associated factors.

Results: Group B showed the greatest AXL increase per year (group B > group C > group A = group D; P < 0.001). During the follow-up periods, the BT configuration initially was changed from internally oblique to externally oblique (group B) and was stretched, resulting in optic disc ovality and γ-zone PPA development (group C). In group C, BL was increased significantly nasally and BTA was decreased significantly, whereas BMOD remained stable (P < 0.001, P < 0.001, and P = 0.100, respectively). In the multivariate analysis using the generalized linear mixed-effect model, the changes of BL and BTA were associated with axial elongation (P = 0.028 and P = 0.010, respectively).

Conclusions: Development of myopic optic disc and γ-zone PPA during myopia progression was delineated using SD OCT images. During the ONH and peripapillary changes, the BL was increased nasally and the BTA was decreased, whereas the BMOD remained relatively stable. The association of axial elongation with ONH and peripapillary tissue changes may facilitate understanding of the relationship between myopia and glaucoma.