Six-Month Versus Nine-Month Anti-Tubercular Therapy for Tubercular Posterior Uveitis: A Multicenter, Randomized Controlled Trial

Purpose The benefits of anti-tubercular therapy (ATT) in treating ocular tuberculosis (TB) are well documented. However, the optimal duration of ATT remains uncertain. We assessed the efficacy of 6-month ATT compared to 9-month therapy in preventing recurrent intraocular inflammation. Design Multi-center, open-label, non-inferiority, randomized controlled trial across three centers in India, Myanmar, and Thailand. Methods Patients aged ≥ 18 years with tubercular posterior uveitis (retinal vasculitis, serpiginous-like choroiditis [SLC] or multifocal choroiditis) were randomized to receive either 6- or 9-month ATT. Systemic corticosteroids were mandatory for SLC and, at the treating physician's discretion, for other phenotypes. The primary outcome measure was the non-recurrence of inflammation 1 year after ATT. Results Sixty-four patients (64.1% males, median age 38 years [22-70], 43.8% bilateral) were randomized across the three sites during the study period. Thirty patients were assigned to the 6-month arm and 34 to the 9-month arm. Both treatments demonstrated a high non-recurrence rate on intention-to-treat (ITT) analysis (0.94 [0.79-0.99] for 9-month [ n = 32] and 0.85 [0.65-0.96] for 6-month treatment [ n = 26]). The difference in proportion remained below the non-inferiority margin (0.16) for both the ITT (0.09 [84% CI -0.02 - 0.2]) and per-protocol (0.13 [84% CI 0.01 - 0.25]) analyses. In subgroup analysis, retinal vasculitis appeared to favor 6-month ATT, and SLC 9-months, with the confidence intervals not deviating on bootstrap resampling. No discontinuation due to drug toxicity was reported in either group. Conclusion Six-month ATT is non-inferior to 9-month ATT for treating tubercular posterior uveitis, though it may vary between the different clinical phenotypes.