1. A man with optic nerve involvement and pernicious anemia regained normal vision after treatment with vitamin B12.
2. In a search of the literature we found 28 cases with both pernicious anemia and optic neuropathy. The hematologic, neurologic and ophthalmologic findings were analyzed in these cases. In each case, the diagnosis of pernicious anemia was established. Optic atrophy associated with pernicious anemia may be part of the pathologic process of pernicious anemia. If the patient is treated early with vitamin B12 or liver extract, optic nerve function returns.
Sixteen other cases with optic atrophy and possible pernicious anemia in the literature had inadequate information to substantiate the diagnosis.
3. The use of a cobalt60-labelled vitamin B12 absorption test may be helpful in optic nerve disorders of obscure etiology.