Carbonic anhydrase inhibitors, such as acetazolamide, are widely used in the treatment of open-angle glaucoma. Severe metabolic acidosis is a rare complication of acetazolamide use, and life-threatening acidosis occurs most commonly in elderly patients, in patients with advanced renal failure, and in patients with diabetes. We describe an unusual case of an elderly patient with diabetic nephropathy and chronic renal failure who presented to the emergency department with severe metabolic acidosis and coma after exposure to high doses of acetazolamide in the postoperative period of ophthalmic surgery. As symptoms of acetazolamide intoxication and uremia are similar, high suspicion is required to detect excessive plasma drug concentrations and intoxication in patients presenting with concomitant uremia. Clinical symptoms are potentially reversible with prompt diagnosis and treatment, including supportive treatment, bicarbonate therapy, and renal replacement therapy. Hemodialysis is particularly helpful in the management of acetazolamide overdose as the medication is dialyzable.