Visual acuity and structure‐function relationships in acute and chronic LHON patients treated with idebenone

Abstract

AbstractPurposeLeber's hereditary optic neuropathy (LHON) is a mitochondrial disease characterised by a subacute and progressive impairment and subsequent degeneration of macular retinal ganglion cells and their nerve fibres causing permanently reduced visual acuity (VA) in most cases. Idebenone is currently the only approved treatment for LHON. This study aims to evaluate the course of VA and its correlations with inner retinal layer morphology in LHON patients treated with idebenone.Methods42 eyes of 21 genetically confirmed LHON patients treated with idebenone were examined in regular intervals. VA was measured using logMAR charts. Macular ganglion cell layer volume (GCLV) and peripapillary retinal nerve fibre layer thickness (pRNFLT) were measured by spectral domain OCT. Patients were divided into three groups according to their time from LHON onset until treatment start including acute patients (<1 year, 12 eyes), chronic group 1 (1 to 5 years, 14 eyes) and chronic group 2 (>5 years, 16 eyes).ResultsA significant increase of VA compared to minimum VA was observed in all groups (acute: ‐0.25 logMAR, chronic 1: −0.29 logMAR, chronic 2: −0.31 logMAR; p < 0.001 all groups). VA at baseline was similar between groups, but 6 eyes of 4 acute patients showed a marked decline during the first year reaching a minimum after 9 months. Minimum VA of all patients was significantly correlated with final pRNFLT (r = 0.48, p = 0.002) and GCLV (r = 0.40, p = 0.008), but OCT and maximum VA during continued treatment showed stronger correlations (pRNFLT: r = 0.50, p = 0.001; GCLV: r = 0.43, p = 0.004). VA gain was not associated with OCT and not different between all groups.ConclusionsVA in LHON patients with recent disease onset can decrease during the first months of treatment with idebenone. The increase of VA after this nadir is comparable to the treatment effects observed in chronic patients and may be the result of a reactivated signal transduction in surviving dysfunctional ganglion cells.