Neuro-ophthalmology of mitochondrial diseases.

Polymorphism in mitochondrial DNA necessitates careful scrutiny of potentially pathogenic mutations to establish their true pathogenic significance. Research on Leber hereditary optic neuropathy continues to provide insights into the pathogenesis of mitochondrial disease. Interest in the retinal manifestations of mitochondrial disease has highlighted the macular dystrophy of the 3243 mutation, particularly in association with the syndrome of maternally inherited diabetes and deafness. Mitochondrial encephalopathies present in a number of ways, but imaging predominantly shows abnormalities of myelin and grey-matter nuclei. The mitochondrial myopathies provide insights into interactions between nuclear and mitochondrial DNA mutations and parallels between mitochondrial diseases and aging.