Alterations in multifocal visual evoked potentials during the acute phase of Leber's hereditary optic neuropathy

This report aimed to investigate alterations in multifocal visual evoked potentials (mfVEPs) during the acute stage of Leber's hereditary optic neuropathy (LHON).

A 27-year-old woman with a point mutation at nucleotide 11778 in the mitochondrial DNA was examined during the acute phase of LHON, which is generally investigated only rarely because of its rapid progress. She was examined repeatedly, with testing of best corrected visual acuity, pupil function, Goldmann perimetry, ophthalmoscopy and frequent assessment of mfVEPs.

Multifocal VEPs, which reveal topographical information about different parts of the visual pathways, demonstrated reduced responses in all parts of the central visual field. The mean amplitude (summarized amplitude of the first two components) in the mfVEPs in the previously described sector C, which has been identified as a hallmark of other optic nerve disorders, was evaluated. This amplitude demonstrated a correlation with the progression of the disease during the acute period of LHON, which also correlated with the VA, pupil function and Goldmann perimetry.

These alterations in the components of mfVEPs reflect the reduction in the function of the visual pathways in different parts of the central field; the drop in amplitude in a localized area (sector C), not previously described, demonstrates the acute course of this disorder. Multifocal VEPs may be of further interest in evaluating the pathogenesis of this disorder and of clinical value in representing an objective method for monitoring the course of this disease.