8158 Transient Blindness In Metformin-Associated Lactic Acidosis

Abstract Disclosure: Y. Abouelkheer: None. A. Nasir: None. M. Ibrahem: None. Transient Blindness in Metformin-associated Lactic Acidosis Background: Metformin-associated lactic acidosis (MALA) is a rare side effect of metformin use. MALA can result in acute transient blindness in patients with severe metabolic derangements. Clinical Case: A 62-year-old woman presented with severe diarrhea, poor oral intake, malaise, and vomiting on a background of metformin-treated type 2 diabetes mellitus. Laboratory investigations showed bicarbonate <2 mmol/L, anion gap 48 mmol/L, lactic acid 20.5 mmol/L, serum osmolality 352 mOsm/kg, negative urine toxicology screen, and positive SARS-CoV-2. In the emergency department, the patient developed sudden onset bilateral vision loss. The examination was remarkable for complete vision loss bilaterally in all fields, associated with minimally reactive pupils and spontaneous ocular movements with an otherwise unrevealing neurological examination. Computed Tomography (CT) of the brain with stroke protocol showed no evidence of acute intracranial process. CT angiogram of the brain and neck showed patent intracranial and cervical vasculature without high-grade stenosis, large vessel occlusion, or aneurysm. While receiving medical management with intravenous fluid resuscitation and sodium bicarbonate supplementation, the patient had a spontaneous return of vision with no additional neurological complications or deficits. The severe metabolic derangements were associated with distributive shock, requiring admission to the intensive care unit for urgent hemodialysis, pressor support, empiric antibiotics, and stress-dose steroids. Shortly after the patient’s only hemodialysis session, we noted the resolution of her critical metabolic disturbances, renal failure, and shock state. Laboratory investigations post-dialysis showed bicarbonate 12 mmol/L, anion gap 36 mmol/L, and lactic acid 10.5 mmol/L. Follow-up MRI showed chronic lacunar infarct of the left basal ganglia, and she was discharged home six days later. Conclusion: Transient blindness in MALA can mimic acute neurovascular events. Prompt correction of metabolic derangements can aid in reversing systemic symptoms and blindness. Reference: DeFronzo R, Fleming GA, Chen K, Bicsak TA. Metformin-associated lactic acidosis: Current perspectives on causes and risk. Metabolism. 2016;65(2):20-29. doi:10.1016/j.metabol.2015.10.014 Presentation: 6/2/2024