Bilateral Optic Atrophy Following Methanol Poisoning: A Case Report

Abstract

Background: Methanol is an industrial chemical found in many products including antifreeze solutions, solvents and fuels. Most cases of methanol poisoning among humans occur following accidental ingestion, inhalation or dermal exposure. Humans may sometimes ingest methanol as an ethanol substitute or to inflict injuries on themselves. Multiple victim methanol poisonings can occur with illicit distillation or occult substitution of methanol for ethanol. The clinical diagnosis is made in the presence of toxic alcohol ingestion, early visual symptoms and unexplained metabolic acidosis.  Case Report: We report a case of methanol poisoning with bilateral optic atrophy in a 53-year old carpenter who presented to the ophthalmology clinic, University of Port Harcourt Teaching Hospital on 9th June 2015 on account of eight days history of sudden loss of vision in both eyes, following ingestion of alcohol with colleagues. Prior to presentation, he had good vision in both eyes.  Clinical examination revealed visual acuity of hand motion in both eyes, widely dilated pupils with no reaction to light. Fundoscopy showed bilateral chronic optic atrophy. Based on the clinical and fundus photographic findings and the epidemiological report of methanol poisoning outbreak in Rivers State at this particular time from 30th May 2015 to 15th June 2015), a diagnosis of methanol poisoning was entertained. Patient was treated with folic acid, prednisolone and multivitamins. Conclusion: Early recognition and treatment of methyl alcohol poisoning could prevent hazardous outcome. Late Presentation of our client worsened by poverty and ignorance led to optic neurotoxicity, with bilateral blindness. Practising ophthalmologist should have a high index of suspicion of alcohol related chronic optic neuropathy with blindness among chronic alcoholics.