Bitemporal visual field defects in presumed multiple sclerosis.

Three patients with presumed multiple sclerosis had bitemporal hemianopia mimicking that caused by parasellar tumors; the visual loss was probably due to a plaque within the chiasm. The diagnosis of multiple sclerosis was made on the basis of a history of relapse and remission, signs and symptoms indicating involvement of different levels of the central nervous system, and normal neuroradiological studies. Extensive neuroradiological studies may be delayed or omitted in patients with established multiple sclerosis and nonprogressive bitemporal visual field defects if central visual acuity is not greatly reduced.