[Leber's Hereditary Optic Neuropathy]. / Leberʼsche hereditäre Optikusneuropathie.

ABSTRACT

Leber's hereditary optic neuropathy (LHON) typically affects young adults with a higher prevalence in men, but can ultimately occur at any age and also in women. LHON is caused by point mutations in the mitochondrial DNA, which lead to a defect in complex I of the mitochondrial respiratory chain. This in turn causes dysfunction and later degeneration of retinal ganglion cells, followed by ascending optic atrophy. Classically, LHON presents as a subacute unilateral loss of visual acuity, dyschromatopsia in the red-green axis and a central or centrocecal scotoma. The partner eye usually develops similar symptoms within 3 - 6 months of onset of the disease. In 25% of cases, however, the disease begins bilaterally. In the natural course of the disease, the majority of patients remain with a visual acuity less than 0.1, even though a small proportion may experience a spontaneous improvement in visual acuity. In 2015, the ubiquinone analogue Idebenone was approved by the European Medicines Agency for the treatment of LHON. The decisive factors for therapeutic success are an early start and an appropriate treatment duration. It should also be noted that a proportion of patients may experience a delayed response to therapy. However, a complete recovery of visual acuity is rare even under therapy. Since patients affected by LHON are mostly young adults of working age, who go largely blind more or less acutely, immediate support with magnifying vision aids and advice on social and vocational rehabilitation is essential. Alternative therapeutic approaches such as gene therapy, neuroprotection or stem cell-based aspects are currently the subject of clinical studies and offer hope for further perspectives for those affected. Although with Idebenone a causal therapy has already been approved for LHON, many questions regarding the pathogenesis of the disease have not yet been completely clarified. This particularly concerns gender prevalence and possible additional triggers or protective factors. In this overview, the clinical course of LHON, diagnostics and current therapy recommendations as well as the special features and current explanatory approaches to incomplete penetrance and symptoms of LHON are explained.