Bilateral optic neuropathy associated with multiple myeloma.

A 51-year-old man had reduced vision and bilateral optic disc swelling as the initial clinical manifestation of multiple myeloma. Brain imaging failed to disclose any abnormalities. Before any therapy was begun, visual function began to improve substantially. Three months after chemotherapy was started, visual function and optic disc appearance returned to near normal. There were no features to suggest polyneuropathy-organomegaly-endocrinopathy-M protein-skin changes (POEMS) syndrome. Visual loss in myeloma is usually caused by compression or infiltration of the optic nerves by tumor. The mechanism of the optic neuropathy in this case remains unknown.