Outcomes of Idebenone Therapy for Leber Hereditary Optic Neuropathy in a cohort of patients from Wales

Background Leber hereditary optic neuropathy (LHON) poses a significant burden to patients with with the majority not showing significant spontaneous improvement in their vision. The recent validation of idebenone as a therapy provides some avenue for benefit for patients with LHON in Wales, where it has been approved for use within the NHS. Methods From March 2021 all patients being seen in a tertiary referral clinic and diagnosed with LHON by targeted genetic testing were offered treatment with idebenone and commenced on idebenone as part of standard care. For such patients their clinical records were used to collect demographic and outcome data. Visual acuity was analysed for clinically relevant recovery (CRR) defined as improvement from “off-chart” to “on-chart” or “on-chart” improvement of at least 10 letters. Results A total of 12 (67% male) individuals were treated with idebenone 300mg TDS for LHON for a mean period of 30.2 (±9.9) months. Two patients were lost to follow up after initiation of therapy, and two patients ceased therapy after 30 and 35 months respectively. Mean visual acuity at initiation of therapy was 2.22 (±0.32) LogMAR, improving to a peak of 1.12 (±0.77) LogMAR at 27 months. This timepoint was coincident with the maximum CRR achieved with 86% demonstrating CRR. Conclusion The present cohort demonstrates evidence of CRR in a high proportion of patients reaching 27 months of treatment. Further follow up and a larger cohort of patients will provide further insight into the real-world efficacy of idebenone in LHON.