Acute blindness and putaminal necrosis in methanol intoxication

To review the neuro-ophthalmological and radiological findings of acute methyl alcohol intoxication.

8 acute methyl alcohol intoxication cases were evaluated.

All patients were male and their ages varied between 21 and 55. At the initial examination, 6 to 12 days after methanol intake, visual acuity ranged from no light perception to counting fingers at 2 meters with no color perception. Bilateral dense central scotomas were detected in patients whose vision was slightly preserved. Pupillary light reactions were either absent or sluggish. In 4 cases, edema of the optic disk and the peripapillary nerve fiber layer was observed. Three months later, optic atrophy had developed. Five patients underwent magnetic resonance imaging. Bilateral putaminal hyperintense lesions on T2 weighted images were observed in 3 cases. Two patients died and autopsy permission could not be obtained. Follow-up examination 12 months later revealed optic atrophy in the other six cases, with no improvement in vision.

Methanol intoxication is detrimental to health, possibly resulting in blindness and occasionally death. In association with ocular signs and the other systemic and laboratory features, the ophthalmologist should be alert to the diagnosis of methanol intoxication in which visual loss may be the only symptom.