Pupillary function in multiple sclerosis.

Eighteen MS patients with visual acuity of 20/30 or better and without recent visual complaints, and 14 age- and sex-matched controls were studied by TV pupillography. The response amplitude and the maximum rate of pupillary constriction or dilation of the light, dark, accommodation and ciliospinal reflexes were unchanged. The latency of the pupillary light response (PLR), however, was prolonged and closely related to walking performance (R = 0.76; p less than 0.001). No relationship was established between PLR latency and previous history of optic neuritis or latency of the VEP. It is concluded that MS patients with preserved visual acuity have only discrete autonomic pupillary disturbances and that the PLR delay is related to disease progression.