Background: To characterize the clinical features of Leber's hereditary optic neuropathy (LHON) in Taiwanese patients with the 11778 mutation of mitochondrial DNA (mtDNA).
Methods: A retrospective review of the clinical manifestation was undertaken in 13 LHON patients with the 11778 mtDNA mutation from 1994 to 2001 in Chang Gung Memorial Hospital.
Results: The male-to-female ratio among patients was 12:1 (92% male). The age at onset of visual loss for the first eye ranged from 7 to 30 years old, with a mean of 19.4 years. The time interval between when the second eye was affected ranged from simultaneous onset to 7 months (mean, 2.2 months). The final visual acuity was 0.1 or worse in 24 eyes (92.3%). A suspect fundus was present in 14 of 26 eyes (54%). Patients with later onset of visual loss (< 20 years) tended to have better final visual acuities. Abnormal visual evoked potentials (VEPs) were recorded after acute onset of visual loss in all of our patients and even before onset of visual symptoms in 1 patient.
Conclusions: The clinical characteristics of our patients harboring the 11778 mitochondrial mutation are mostly similar to those previously reported from other countries. In addition to the common features of LHON, we also noted that there was a relationship between age of onset and visual prognosis. We also suggest that VEP is a good indicator for predicting visual loss.