Persistent ocular motor manifestations and related visual consequences in multiple sclerosis

Abnormal eye movements in multiple sclerosis (MS) are often persistent and known to be associated with general disability. However, there is no precise knowledge concerning their incidence and resulting visual handicap. The aim of our study was to describe the persistent ocular motor manifestations in MS and relate them to visual functions tested with visual acuity and with a vision-related questionnaire. We selected 24 MS patients complaining of persistent visual disability associated with ocular motor manifestations without any anterior visual pathway deficit. Internuclear ophthalmoplegia was the most frequently observed symptom, followed by gaze-evoked nystagmus, saccadic hypermetria, and then pendular nystagmus. Pendular nystagmus, saccadic hypermetria, and the association of internuclear ophthalmoplegia and gaze-evoked nystagmus were associated with decreased visual acuity and visual functional scores. There was a correlation between the number of abnormal eye movements and visual functions. This study demonstrates that ocular motor dysfunction in MS induces specific visual dysfunction and handicap.