Acute Visual Loss After Thioridazine Overdose

Mr. A, a 29-year-old man, was admitted to the emergency department while unconscious. He had ingested in excess of 1500 mg of thioridazine with a moderate amount of alcohol. Two years before this hospitalization, he had been maintained with thioridazine, 100 mg/day, to treat a psychiatric illness. On admission his blood pressure was 90/50 mm Hg, and his pulse was 110 bpm. The next morning, before further assessment, he left the hospital. He visited his general practitioner 11 days later complaining of decreased vision since the overdose and was referred for ophthalmological assessment.

His visual acuity was 3/60 in the right eye and 2/60 in the left eye. His pupils were dilated, and he had a sluggish, minimal reaction to light. A fundoscopy revealed poorly perfused retinal arteries with diffuse retinal edema and bilateral cherry-red maculae that were consistent with central retinal artery nonperfusion. The results of a Goldmann field test showed that his visual field was constricted to a central island. These findings were unchanged at a review conducted 1 week later. Fundus fluorescein angiography showed arterial and venous nonperfusion with poor choroidal perfusion. Subsequently, Mr. A failed to return for follow-up and electrodiagnostic tests.