Minimum Ganglion Cell Layer Thickness is the Best Structural Predictor of Visual Function in Leber Hereditary Optic Neuropathy

Abstract

Background: Patients with Leber hereditary optic neuropathy, a genetic cause of severe optic atrophy and blindness, demonstrate characteristic structural changes measurable through optical coherence tomography, including initial swelling of the retinal nerve fiber layer and progressive thinning of the ganglion cell layer. After symptomatic conversion, patients experience progressive vision loss, often with dense central scotomas. Aims: This study aims to explore the predictive potential of ocular structural measurements to visual function in patients with Leber hereditary optic neuropathy. Methods: Medical records were reviewed retrospectively for patients with Leber hereditary optic neuropathy clinical testing. Structural measurements, including the average thickness of the ganglion cell layer, the retinal nerve fiber layer, and minimum thickness of the ganglion cell layer, measured through optical coherence tomography were obtained along with measures of visual function such as visual acuity and mean deviation of visual field testing. Simple and multivariable linear regressions were performed to determine correlations between structural measurements and visual functions. Analyses were conducted for all patients, and subgroup of symptomatic patients. Results: Overall, 92 eyes were included with 78 symptomatic eyes. Across all patients, the minimum ganglion cell layer thickness had the highest correlation coefficient with visual acuity (Beta -0.632, adjusted R2 0.396) and with visual field function (Beta 0.572, adj. R2 0.320) compared to the average thickness of the ganglion cell layer (Beta 0.474, adj. R2 0.216) and retinal nerve fiber layer (Beta 0.481, adj. R2 0.223). In multivariate analysis, the minimum ganglion cell layer thickness was the only significant measurement that correlated with visual acuity across all eyes (Beta -0.527, P<0.001) and symptomatic eyes (Beta -0.479, P<0.001). The minimum ganglion cell layer thickness (Beta 0.440, P<0.001) and retinal nerve fiber layer average thickness (0.258, P=0.023) were significant structural measurements correlating to visual field function. Conclusion: The minimum ganglion cell layer thickness is the best structural measure predictor for visual field and visual acuity compared to other common structural measurements in patients with Leber hereditary optic neuropathy. It is a good predictor even when evaluating only symptomatic eyes. Additional attention toward the minimum ganglion cell layer thickness may offer further insight into a patient’s visual potential and the natural history of this disease.