The Visual Evoked Potential in Ischaemic Optic Neuropathy

Abstract

The potentials evoked by pattern reversal (PVEP) and diffuse flash stimulation (FVEP) are described in 11 patients with ischaemic optic neuropathy, the findings being compared with extensive normal control groups. Two of these patients had giant cell arteritis confirmed by temporal artery biopsy.

In both patients with temporal arteritis the PVEP from the affected eye was absent. In the other patients the PVEP from the affected eye invariably showed a significant amplitude reduction compared with the normal eye. A significant interocular latency asymmetry was present in the PVEP of only one of these 9 patients.

Both of the patients with giant cell arteritis had FVEPs of markedly reduced amplitude from the affected eye associated with a delay in the early components, the remainder of the waveform being distorted and precluding accurate quantification of later components including the major positivity. Five of the other 8 patients in whom the FVEP was examined showed a significantly reduced FVEP amplitude from the affected eye, this being accompanied by a significant interocular latency asymmetry in only one patient. FVEPs were normal in the other three patients.

The use of VEP examination in the diagnosis of ischaemic optic neuropathy is discussed.