ABSTRACT
Lebers hereditary optic neuropathy(LHON)is caused by a single nucleotide change in the mitochondrial deoxynucleic acid(mtDNA)and accounts for 30% of bilateral optic atrophy of unknown etiology. In order to define the clinical features of LHON associated with the 11778 mtDNA mutation, clinical and historical data were collected from 60 visually symptomatic patients with the molecularly confirmed mtDNA 11778 mutation. Forty-nine(82%)of the 60 patients were male. Onset of visual loss was between 6 and 63 years of age. Worst visual acuity ranged from light perception to 0.8. In most patients, visual acuities deteriorated to worse than 0.1 and remained at that level. Final visual acuities ranged from light perception to 1.2.Five(8.3%)out of 60 patients showed improvement of visual acuity up to 0.5 or better in at least one eye. Ishihara test revealed severe color vision impairment in most patients. Optic atrophy was the most common ophthalmoscopic finding.However, increased C/D ratio or normal disc was also observed. Central scotoma was the most frequent visual field defect, but normal visual field was also found. LHON should be considered in the differential diagnosis of optic neuropathy in a young man with visual and color deterioration as well as with a central scotoma. However, various phenotypes also exist in an atypical LHON case.