Chiasmopathy?

A 57-year-old man presented with progressive visual loss in both eyes, bite mporal field defect, and a history of poor nutrition, alcohol abuse, and ex cessive cigar smoking. Magnetic resonance imaging was normal. The visual ac uity and field defect improved with supplementation with vitamins and reduc tion of alcohol and tobacco consumption. A diagnosis of toxic optic neuropa thy was made. The authors discuss the differential diagnosis of bitemporal/ pseudobitemporal field defects and the diagnosis and treatment of toxic opt ic neuropathy. (C) 2000 by Elsevier Science Inc. All rights reserved.