Multifocal electroretinogram in multiple evanescent white dot syndrome.

Electrophysiologic findings including multifocal electroretinogram and visual evoked cortical potentials were studied in a patient with multiple evanescent white dot syndrome. A 19-year-old woman was diagnosed as having multiple evanescent white dot syndrome because of decreased visual acuity, white dots on fundus examination and hyperfluorescence of the white dots in the right eye. The amplitude of the flicker electroretinogram was reduced, but the single-flash electroretinogram was within the normal range. The P100 latency of the pattern visual evoked cortical potentials was slightly prolonged. The amplitudes of multifocal electroretinogram were markedly reduced in the area corresponding to the scotoma and moderately reduced in other regions of the central field in the affected eye. The results suggest that the retinal dysfunction area is wider than that detected by subjective methods or conventional electrophysiological examinations. The delayed recovery of the visual evoked cortical potential latency suggests the involvement of the optic nerve in multiple evanescent white dot syndrome.