Additional New Therapeutic Options.

This review article also mentions one of the potential, but rare, differential diagnoses of optic neuritis—Leber’s hereditary optic neuropathy (LHON) (1). LHON results in most cases—with very few exceptions—in pronounced and mostly irreversible loss of vision. This rare pathology has a prevalence of 1–9/100 000. To date, no essential therapeutic intervention for this rare mitochondrial disorder is available. On 9 September 2015, two days before this article was published, the substance idebenone was licensed by the EMA for use within the EU in the context of an orphan drug designation for the treatment of visual impairment in adolescents and adults with LHON. Approval was granted on the basis of data from the RHODOS phase III study (2). The treatment was administered orally for 24 weeks. Even though the primary endpoint was not met in this study, the secondary endpoints showed an improvement in the vision defect compared with untreated patients with LHON. For this reason, it seems to make even more sense to bear in mind LHON as a rare differential diagnosis of optic neuritis. A reliable diagnosis can be made on the basis of confirming the typical mitochondrial DNA mutations, and treatment with idebenone may be considered accordingly.