Tranexamic acid-induced visual impairment in a hemodialysis patient

We report a case of overdosage of tranexamic acid (TNA), which was suggested as the cause of visual impairment in a 56-year-old man. He had been undergoing chronic hemodialysis for 1 year, following 10 years of peritoneal dialysis. He had been hospitalized for an emergency operation for a bleeding ulcer of the stomach and duodenum. After the operation, he experienced a gradual loss of sight over about 1 week, although his general condition was good. He received intravenous injections of TNA as a hemostat during hospitalization for the operation. Two weeks after the operation he became blind. Retinography was flat and his visual field had become narrowed. On fluorescein angiography, microgranular hyperfluorescence, which indicated malfunction of the pigmented layer of the retina, was observed. No abnormality of the brain or the optic nerve was shown by magnetic resonance imaging. Concentrations of vitamins and trace minerals in the blood were within the normal ranges. Administration of vitamins A and B12 did not improve his sight. However, discontinuation of TNA rapidly restored his sight, within a few days. He had received TNA once before because of bleeding ulcer, and his sight had been impaired at that time. Based on the repeated episodes, it was strongly suggested that an overdose of TNA in this dialysis patient caused the sight disturbance. Because TNA is metabolized by the kidney, caution is necessary when prescribing TNA for patients with renal failure.