Toluene Related Toxic Optic Neuropathy

Abstract

Toxic optic neuropathy presenting as bilateral painless visual loss causing central or caecocentral scotoma has a wide differential diagnosis. In this report, we present a rare cause of toxic optic neuropathy presenting as almost indistinct optic disc margins in both eyes in a 30-year old man with blurred vision and difficulty in walking and in writing with a history of adhesive glue sniffing. Caecocentral scotomas in the visual fields; increased total error scores on Farnsworth-Munsell (FM) 100 Hue testing; P 100 reduced amplitude in the pattern visually evoked potentials; and N 95 reduced amplitude in the pattern electroretinogram associated with normal serum electrolytes and vitamin levels suggested acute toxic optic neuropathy related to toluene. Upon cessation of toluene use, the caecocentral scotomas almost disappeared, total error scores in the FM 100 Hue test decreased and visual acuity improved.