The ganglion cell complex thickness and visual function in leber hereditary optic neuropathy

Abstract

Purpose: To evaluate the ganglion cell complex (GCC) thickness using the Iowa Reference Segmentation Algorithm in individuals with chronic Leber hereditary optic neuropathy (LHON) and to assess its relation to visual acuity, visual field sensitivity, and Estermann score.Methods: In this study, a total of 17 patients (34 eyes) aged 16–72 with chronic LHON were enrolled. Visual acuity, visual fields, and Optic coherence tomography (OCT) were performed. Visual fields was evaluated with Estermann and a custom central 30‐degree test, both performed monocularly with the Octopus 900 Haag‐Streit Diagnostics. OCT imaging was performed using a Canon OCT HS‐100 to measure the retinal ganglion cell complex (GCC) thickness. The raw OCT images were exported to IOWA Reference Algorithm and the GCC segmentation was rechecked and manually recorrected if needed. The thickness obtained from the Iowa Reference Algorithms was analysed and compared against the automated segmentation provided by the OCT's inbuilt segmentation algorithm. The correlation between the GCC thickness from 9 ETDRS sectors and the visual function were analysed.Results: On average the automated segmentation overestimated GCC thickness by 23.8 μm for all sectors. Macular central GCC correlated significantly with both visual field sensitivity and Estermann points missed (r = −0.486 and −0.396 respectively). Macular middle sector GCC thickness correlated significantly with visual acuity and visual field sensitivity (r = −0.586 and −0.396 respectively). GCC thickness in outer macular sector correlated significantly only with visual acuity (r = −0.471).Conclusions: In patients with chronic LHON, GCC thickness in central and middle sectors of macula correlates well with the visual function. OCT imaging and precise ganglion cell thickness evaluations in the macula can provide useful information about the structural damage and level of visual impairment in chronic LHON patients.