The optic nerve in multiple sclerosis: A morphological study with retrospective clinico-pathological correlations

Abstract

We examined both optic nerves in 18 cases of chronic multiple sclerosis histologically. Thirty-five of these 36 nerves showed demyelination. In only eight patients had a history of unilateral or bilateral optic neuritis been recorded. The visual acuity of 15 of these patients had been recorded. In statistical analysis the loss of visual acuity correlated with the extent of demyelination in the optic nerves. In some cases, however, useful visual acuity proved to be compatible with the complete demyelination of the total cross section of the nerves over a length of 1 cm and more. These findings are considered to be evidence that conduction can take place in demyelinated nerve fibers running through relatively large demyelinated areas. At the same time the correlation between functional impairment and demyelination points to a crucial role played by demyelination in chronic multiple sclerosis.