Management of LHON ‐ An update

Leber hereditary optic neuropathy (LHON) is a devastating cause of blindness that predominantly affects young adult men. Over 90% of patients harbour one of three mitochondrial DNA point mutations, namely, m.3460G>A (MT‐ND1), m.11778G>A (MT‐ND4) and m.144484T>C (MT‐ND6). Idebenone is the only approved treatment for LHON. New evidence has refined the management guidelines for idebenone, in particular the duration of treatment and the therapeutic window of opportunity. Gene therapy using allotopic expression is an attractive strategy for LHON as it corrects the underlying mitochondrial DNA defect. Promising results have been obtained for the m.1178G>A (MT‐ND4) mutation for patients treated within 1 year of disease onset with an intravitreal injection of a modified adeno‐associated viral vector carrying the replacement gene.