Ocular TB as the only manifestation of TB: diagnostic uncertainty and treatment thresholds

To review diagnostic approaches and treatment thresholds for presumed tuberculous uveitis when ocular inflammation is the only manifestation of tuberculosis (TB), focusing on phenotype-based risk stratification, interferon-gamma release assay (IGRA) interpretation, mimic exclusion, and evidence for antitubercular therapy (ATT).

Narrative review using targeted PubMed search of ocular TB literature. Search terms included "ocular tuberculosis", "tuberculous uveitis", specific phenotypes (serpiginous-like choroiditis, retinal vasculitis, tuberculoma), and treatment outcomes. We prioritized consensus guidelines, systematic reviews, meta-analyses, and randomized data. Findings were synthesized into a phenotype-anchored diagnostic and treatment algorithm.

Ocular TB is usually diagnosed through a comprehensive assessment of ocular phenotype, epidemiologic risk, systemic evaluation, TB immunologic testing, and mimic exclusion. Higher-suspicion phenotypes include serpiginous-like choroiditis, occlusive retinal vasculitis, choroidal tuberculoma, anterior uveitis with iris nodules, and chronic granulomatous anterior uveitis in the appropriate clinical context. IGRA results support prior TB sensitization but do not establish ocular causality; positive results may be incidental, particularly in low-burden settings, while negative results do not fully exclude ocular TB when phenotype and epidemiologic context are strongly suggestive. Consensus guidance and recent randomized evidence support ATT in selected patients, but treatment thresholds remain phenotype- and context-dependent.

Compatible ocular phenotypes should prompt TB-directed evaluation, including IGRA and systemic assessment, with immunologic testing interpreted as supportive evidence. Treatment decisions should consider phenotype, epidemiological risk, mimic exclusion, and consequences of delayed treatment. High-risk presentations may justify lower treatment thresholds, while nonspecific ocular findings with isolated immunologic positivity should prompt consideration of alternative diagnoses or LTBI management according to local guidance.