Optic neuropathy in vitamin B₁₂ deficiency

There are many neurological manifestations of vitamin B₁₂ deficiency. Optic neuropathy is a rare, but important, manifestation of vitamin B₁₂ deficiency that should be suspected in patients with risk factors for malnutrition. We present a case of a 68-year-old male who presented with bilateral decreased central vision for months and was found to have a low vitamin B₁₂ level. After a few months, his vision improved with parenteral vitamin B₁₂ supplementation. Vitamin B₁₂ optic neuropathy is a reversible, treatable cause of vision loss and may be a harbinger for other manifestations of the disease.