Metformin: Metabolic acidosis and vision loss.

A 68-year-old man experienced metabolic acidosis and vision loss while being treated with metformin for diabetes mellitus. The man had a history of diabetes and was also taking glibenclamide and sitagliptin. After traveling to Tanzania, he developed severe pain in his lower limbs and returned to India. He was hospitalized and found to have significant renal dysfunction. Following dialysis, he suddenly lost vision in both eyes, but his vision gradually improved after receiving treatment in the ICU. The man's metabolic acidosis was corrected, and further tests revealed positive urine myoglobin and elevated creatine phosphokinase levels. [Extracted from the article]