Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder 
characterized by bilateral painless optic atrophy and blindness. It usually 
occurs in young men in association with three major mutations in the 
mitochondrial genome (mtDNA). We report a patient with a history of alcohol 
abuse who developed at age 63 years visual impairment, sensorineural hearing 
loss, and memory dysfunction, suggestive of Susac's syndrome. The patient 
carried the heteroplasmic mt. 11778G>A mutation on the T2e mtDNA haplogroup. It 
remains unclear if chronic alcohol abuse combined with the mitochondrial genetic 
background prompted an aged-related neurodegeneration or deferred the onset of 
the LHON disease.