An international study has found that a significant proportion of patients with ocular tuberculosis (OTB) experience a relapse of uveitis even after successful initial treatment. The research, which followed patients over a 10-year period, highlights the challenges in managing this extrapulmonary manifestation of tuberculosis and identifies key risk factors for relapse.
The study, conducted by researchers from Indonesia, The Netherlands, the UK, and Singapore, retrospectively analyzed 93 cases of OTB. Of these, 75 patients achieved clinical inactivity following treatment, with a median time to inactivity of 3.97 months. However, during a median follow-up of 20.7 months after achieving clinical inactivity, 25 of these 75 patients (33.3%) experienced a relapse of uveitis.
Risk Factors and Relapse Characteristics
The researchers found that patients who were considered poor responders to the initial uveitis treatment had a significantly higher risk of relapse after achieving clinical inactivity (adjusted hazard ratio, 3.84; 95% confidence interval, 1.28-11.51). This suggests that the initial response to treatment is a crucial predictor of long-term outcomes in OTB.
Of the 25 patients who relapsed, 13 experienced multiple uveitis relapse episodes, accounting for a total of 78 eye-relapse episodes during the observation period. A significant proportion of these episodes (59.0%) manifested as anterior uveitis. Notably, a substantial number of uveitis relapse episodes (39.7%) were effectively managed with topical corticosteroids, indicating that in many cases, more aggressive interventions like restarting antitubercular treatment (ATT) may not be necessary.
Implications for Clinical Management
The study's findings have important implications for the clinical management of OTB. According to the researchers, "The intraocular inflammation status at 6 months following treatment initiation for the initial uveitis appeared to be a significant predictor of relapse prognosis. Poor responders for the treatment of the initial uveitis episode were at a significantly higher risk of experiencing a relapse after achieving clinical inactivity."
This highlights the need for close monitoring of OTB patients, particularly those who do not respond well to initial treatment. Regular follow-up and prompt management of uveitic relapses are essential to prevent long-term complications and vision loss. The fact that many relapses can be effectively managed with topical corticosteroids is encouraging, as it suggests that less toxic and invasive treatments can be sufficient in many cases.
Context of Ocular Tuberculosis
Tuberculosis primarily affects the lungs, but the eye can also be affected as an extrapulmonary site. The prevalence of OTB among patients with uveitis can range from 3% in non-high-burden settings to 7-11% in high-burden settings. Treating OTB can be challenging, and while ATT is recommended for patients with tubercular choroiditis, serpiginous-like choroiditis, or tuberculoma who also have signs of systemic TB, the decision is more complex in the presence of uveitic manifestations.
This study provides valuable insights into the long-term outcomes of OTB treatment and underscores the importance of identifying and managing risk factors for relapse. Further research is needed to better understand the mechanisms underlying uveitic relapses in OTB and to develop more effective strategies for preventing and treating this challenging condition.
