From the Research
Tuberculosis (TB) can cause homonymous hemianopia, particularly in cases where it affects the central nervous system, such as tuberculous meningitis or tuberculomas, with the specific type depending on the location of the lesion along the visual pathway. Hemianopia refers to blindness in half the visual field and is not a characteristic feature of TB infection. However, in rare cases where TB involves the visual pathways in the brain, it can potentially cause visual field defects including hemianopia. For example, a tuberculoma affecting the optic tract could cause a contralateral homonymous hemianopia, while one affecting the optic radiation might cause a quadrantanopia. According to a study published in the Korean journal of ophthalmology 1, a patient with tuberculous meningoencephalitis developed a right homonymous visual field defect, suggesting that TB can indeed cause homonymous hemianopia in some cases. CNS tuberculosis requires prompt treatment with standard anti-TB medications (isoniazid, rifampin, ethambutol, and pyrazinamide) for at least 9-12 months, along with corticosteroids in cases of meningitis to reduce inflammation and prevent complications. Any visual symptoms in a patient with TB should prompt immediate neurological and ophthalmological evaluation to identify the cause and location of the lesion.
Some key points to consider:
- The location of the TB lesion along the visual pathway determines the type of hemianopia that occurs
- Homonymous hemianopia can occur in cases of tuberculous meningitis or tuberculomas
- Prompt treatment with anti-TB medications and corticosteroids is essential to prevent complications and reduce inflammation
- Regular follow-ups and immediate evaluation of visual symptoms are crucial in patients with TB. It's worth noting that while the study by 1 provides insight into the potential for TB to cause homonymous hemianopia, other studies such as 2 and 3 discuss the ocular side effects of antitubercular drugs and the importance of early detection and management, but do not directly address the type of hemianopia caused by TB.