Transient vision loss in a patient with severe metformin-associated lactic acidosis

Abstract

A 54-year-old male, insulin-dependent diabetic and chronic kidney disease stage I, was brought to Emergency Department with a complaint of acute vision loss, severe hypoglycemia, hyperventilation, metabolic acidosis and acute renal failure. Five days prior to admission suffered diarrhea and vomiting with loss of vision at the last 12 h. Home medications included insulin lantus, valsartan 160 mg, amlodipine 5 mg and metformin 850 mg twice a day. There was not previous history of drinking alcohol, smoking or drugs abuse. In the emergency room, physical examination revealed an ill man with a Kussmaul respiratory pattern with 34 breaths/min, dry mucous membranes and skin. Blood pressure was found to be 70/52 mmHg, heart rate 101 beats/min, temperature 36.8°C and pulseoximeter reading was 99% on room air. The patient was lying calmly supine on stretcher under bright lights with his eyes opened, and he answered questions slowly in one or two words. He had no signs of trauma in the head or body. Neurological examination showed slight confusion. No focal neurological deficit was seen. His pupils were midsized, equal and normal to react. Fundoscopic examination revealed bilateral proliferative diabetic retinopathy with vitreous hemorrhage. Visual acuity and fields were not normal. Laboratory data are shown in Table 1. His baseline renal function before admission was assessed by estimated glomerular filtration rate (modified diet …