Tobacco-alcohol amblyopia: a diagnostic dilemma.

INTRODUCTION Tobacco alcohol amblyopia is an outdated term for a rare condition characterized by visual impairment due to tobacco and alcohol abuse usually associated with nutritional deficiencies. The more accurate term used now is Nutritional Optic Neuropathy. The visual impairment generally presents as a centrocecal scotoma. Its pathophysiology is poorly understood but it is generally attributed to toxic effects of cyanide and B12 deficiency. DESIGN/SUBJECTS 61 year old male presented with one month history of altered mental status and progressive, painless, bilateral vision loss in the setting of severe alcohol and tobacco abuse and poor nutrition. Patient developed loss of central vision in the left-eye and blurring of vision in the right-eye after 1 week, which was reduced to only perception of hand movements by the time of presentation. His BMI was 19.3 with an emaciated appearance. On ophthalmological exam, visual-acuity was 20/200 (right) and 20/300 (left), with a left central scotoma and normal fundoscopic exam. Neurological examination was significant for confabulation and gait instability consistent with Wernickes Korsakoff. Workup included negative imaging and normal B12, folate and thiamine levels, undetectable cyanide levels, and negative Leber's Hereditary Optic Neuropathy mutation. He was discharged after 30 days, after a steady reversal of his symptoms in the setting of abstinence and nutritional supplementation. A diagnosis of tobacco alcohol amblyopia was made by exclusion and by history. RESULTS This case of tobacco alcohol amblyopia has an atypical presentation because of normal fundoscopic exam, undetectable cyanide levels and normal B12 levels. It reinforces the need for biomarkers for this disease. Nutritional fortification has made these cases rare, but a neurological perspective may be essential for accurate diagnosis, treatment and positive outcome for these patients. CONCLUSION Tobacco alcohol amblyopia can be a difficult diagnosis due to lack of biomarkers and rare occurrence. A neurologist can facilitate diagnosis in atypical cases.