Fig. 1

Leber hereditary optic neuropathy is a mitochondrial disorder characterised by bilateral sequential vision loss with limited treatment options. Idebenone, a benzoquinone, is the only drug currently approved for LHON by the European Medicines Agency. Its suggested mechanism of actions includes improving mitochondrial function and reducing retinal ganglion cell death [1]. This infographic summarises the design and results of the LEROS Trial. This trial was a multicentre, non-randomised, phase IV trial evaluating the use of idebenone versus a cohort of natural history comparators gathered from electronic databases. Participants taking idebenone were recruited from centres across Europe and the United States between 2016 and 2021, with the natural history cohort coming from two case report surveys conducted in Europe in 2013 to 2014. The idebenone cohort was significantly more likely to have clinically relevant benefit at all disease stages and at both 12 and 24 months than the natural history comparators. Clinically relevant benefit was defined as +5 letters on ETDRS charts if off-chart and +10 letters if on-chart [2].