A 37-year-old woman presenting with impaired visual function during antituberculosis drug therapy: a case report

A 37-year-old Yoruba woman, weighing 48 kg, presented to our facility with impaired visual functions and mild sensory polyneuropathy in about the fourth month of antituberculosis treatment. Her therapy comprised ethambutol 825 mg, isoniazid 225 mg, rifampicin 450 mg, and pyrazinamide 1200 mg. Her visual acuity was 6/60 in her right eye and 1/60 in her left eye. She had sluggish pupils, red-green dyschromatopsia, hyperemic optic discs and central visual field defects. Her intraocular pressure was 14 mmHg. Her liver and kidney functions were essentially normal. Screening for human immunodeficiency virus was not reactive. Her impaired visual function improved following prompt diagnosis and attention, including the discontinuation of medication.The ethambutol and isoniazid in antituberculosis medication are notorious for causing impaired visual function. The diagnosis of ocular toxicity from antituberculosis drugs should never be delayed, and should be possible with the patient's history and simple but basic eye examinations and tests. Tight weight-based antituberculosis therapy, routine peri-therapy visual function monitoring towards early detection of impaired function, and prompt attention will reduce avoidable ocular morbidity.Tuberculosis is a multisystemic and wide-ranging communicable disease across the globe, specifically in resource limited economies. It is caused by a type of acid-fast and alcohol-fast mycobacteria. The bacilli are difficult to treat and there may be resistance, which is common in immunosuppressed states, especially human immunodeficiency virus (HIV) and/or acquired immunodeficiency syndrome (AIDS). However, the 'combination drug therapy' employed in the treatment of tuberculosis has been hailed as a medical breakthrough.Various combination drug regimens are employed in the treatment of tuberculosis. The common combination drug therapy is one comprising the 'first-line' antituberculosis drugs including ethambutol, isoniazid, rifampicin and pyr