Paradoxical reactions in ocular tuberculosis.

Paradoxical reactions following initiation of anti-tubercular therapy have been documented most often in extrapulmonary tuberculosis. A combination of factors such as delayed hypersensitivity, decreased suppressor mechanisms, and an increased response to mycobacterial antigens mediated by the host's immune system have been implicated in the development of these reactions. Similar worsening in patients with ocular tuberculosis while on treatment has been described. It is therefore important for the clinician to be aware of this occurrence, as prompt recognition and timely institution of corticosteroids and immunosuppressants can lead to restoration of vision. In these patients, an alteration or discontinuation of anti-tubercular therapy may not be indicated.