Optic Neuropathy Associated with Folate Deficiency

Tobacco-alcohol amblyopia is characterized by a symmetric, bilateral optic neuropathy and is thought to be due, in part, to vitamin B-12 deficiency. Most investigators believe the frequently observed concurrent folate deficiency has little functional significance. Although observed by Knox and others, optic neuropathy associated with isolated folate deficiency has not been well documented. We report five patients who abused ethanol and tobacco, had normal vitamin B-12 levels, but developed folate deficiency and bilateral optic neuropathy.