Subclinical optic neuropathy in multiple sclerosis. A neuro-ophthalmological investigation by means of visually evoked response, Farnworth-Munsell 100 Hue test and Ishihara test and their diagnostic value.

Affection of the optic nerves play a central role in multiple sclerosis (MS) symptomatology. In reported autopsy series the prevalence of optic neuropathy has approached 100%. In the present study subclinical affection of the optic nerves was investigated by visual evoked response (VER), Farnworth-Munsell 100 Hue test (FM 100 Hue test) and Ishihara plates in 17 patients with normal visual acuity and without a history of acute optic neuritis. Optic neuropathy was demonstrated in 72% of the eyes. The occurrence of optic neuropathy was also investigated by the same methods in 16 patients with previous acute optic neuritis, which was bilateral in 5 patients. Affection of the optic nerves was demonstrated in 95% in this group. The affection of also the fellow eye in patients with previous monolateral optic neuritis is unexplained. It may be an analogue to the symmetry of plaques found in the brain and the spinal cord. The cause of this peculiar distribution of lesions is, like the ethiology of MS, unexplained at present. In comparing the different methods of demonstrating optic neuropathy, VER is recommended as the method of choice.