Optic neuritis complicating measles, mumps, and rubella vaccination.

A 6-year-old boy developed bilateral optic neuritis with decreasing visual acuity 18 days after administration of live attenuated trivalent measles, mumps, and rubella vaccine. The patient was treated with oral corticosteroids. The optic neuritis resolved within several weeks and normal vision returned. An afferent pupillary defect persistent in the more severely involved eye for 14 months following vaccination.