Reversal of severe methanol-induced visual impairment: No evidence of retinal toxicity due to fomepizole

Case Report: We report a case of methanol poisoning exhibiting complete rec overy from severe visual impairment following treatment with ethanol, fomep izole, and hemodialysis. An adult mate presented with central blindness aft er ingesting methanol. Initial visual acuity was <20/800 (finger counting a t 1-2 feet) with retinal edema on fundoscopy, arterial pH 7.19, methanol 97 mg/dL (30 mmol/L), formate 14.3 mmol/L, and ethanol undetectable. The pati ent was treated with ethanol, then fomepizole intravenously (15, 10, then 5 mg/kg), and hemodialysis. Methanol metabolism was effectively blocked by f omepizole even after ethanol had been eliminated, and the patient recovered 20/20 vision by day, 14 with normal fundoscopy. This case report confirms highly efficient inhibition of alcohol dehydrogenase by fomepizole, as well as demonstrate the safety of fomepizole in a patient already, exhibiting e nd-organ retinal toxicity. The potential for fomepizole to inhibit retinol dehydrogenase, an isoenzyme of alcohol dehydrogenase essential to vision, d id not appear to be clinically, significant in this symptomatic methanol-po isoned patient.