New VF Progression Prediction Model Demonstrates ONH Structural Changes from High Myopia

The predictive model based on neural canal minimum cross-sectional area underscores the clinical significance of high myopia-related ONH parameters in glaucoma progression and offers potential for individualized disease management. These images from the study show how the planes of Bruch’s membrane opening and the scleral canal can become misaligned in highly myopic eyes that experience optic nerve head tilt and distortion. Photo: Dai J, et al. Invest Ophthalmol Vis Sci. 2025;66(13):30. Click image to enlarge. The relationship between optic nerve head (ONH) structural changes in those with high myopia and the progression of visual field (VF) defects in highly myopic glaucomatous eyes remains unclear. Researchers in China wanted to measure ONH changes using OCT and investigate their association with the structural and functional progression of primary open-angle glaucoma (POAG) over a 36-month follow-up period. Their recent study, which was published in Investigative Ophthalmology & Visual Science, also sought to identify potential biomarkers for predicting and managing disease progression in glaucoma patients with high myopia. In highly myopic glaucoma eyes, both Bruch’s membrane opening (BMO) and anterior scleral canal opening areas were larger, with more elliptical shapes, a more tilted neural canal that tends to shift nasally and a smaller neural canal minimum cross-sectional area. These eyes also exhibited accelerated functional deterioration in the temporal sector, with more severe baseline VF defects and faster progression.This prospective cohort study enrolled 242 eyes: 97 highly myopic glaucoma eyes with axial length  >26.5mm and 145 open-angle glaucoma (OAG) eyes with axial length ≤26.5mm. ONH parameters, including BMO, anterior scleral canal opening and neural canal minimum cross-sectional area, were quantified via spectral-domain OCT. VF defects and parapapillary retinal nerve fiber layer (pRNFL) thickness were monitored over three years.Compared with OAG, high myopia eyes exhibited larger BMO areas (3.0mm2 vs. 2.3mm2) and anterior scleral canal opening areas (2.6mm2 vs. 2.4 mm2), smaller neural canal minimum cross-sectional area (1.0mm2 vs. 1.3 mm2), and faster temporal VF progression (0.173dB/y vs. 0.060dB/y) and pRNFL thinning (0.96µm/y vs. 0.64 µm/y). Multivariate analysis identified neural canal cross-section as an independent predictor of global progression.The study demonstrated that both the progression rate of temporal average pattern deviation (PD) and the temporal pRNFL loss rate were linearly and positively correlated with the nasal–temporal anterior scleral canal opening area-BMO offset magnitude. An increased offset is associated with enlarged temporal peripapillary atrophy and, in simple high myopia, initial blind spot enlargement.“Unlike BMO and anterior scleral canal opening, the neural canal minimum cross-sectional area is an estimated measure of the cross-sectional area through which axons traverse the ONH rather than a discrete anatomical opening,” the study authors wrote in their paper. As it represents “the overlapping area between BMO and the anterior scleral canal opening area in a plane perpendicular to the neural canal axis, this area diminished as the anterior scleral canal opening area became increasingly offset relative to BMO.”The team of researchers suggested that future research should assess the anterior scleral canal opening-BMO area offset using additional fundus landmarks, such as the fovea, as myopia develops.Click here for the journal source. Dai J, Wang X, Han YX, et al. High myopia-induced optic nerve head deformation and glaucoma progression: a three-year follow-up study. Invest Ophthalmol Vis Sci. 2025;66(13):30. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.