Update on ocular tuberculosis

Despite recent downtrends, tuberculosis remains a worldwide public health concern. This review provides an update on recent demographic data, clinical and experimental data, and diagnostic modalities.

Quantitative PCR showing mycobacterial load in intraocular fluids may have an emerging role in the diagnosis of ocular tuberculosis when used in combination with ophthalmic features of tuberculosis. Recent investigations in porcine models of ocular tuberculosis have provided valuable insight into the microbiologic, histologic, and clinical features of Mycobacterium tuberculosis infection of the choroid. Differentiating features between sarcoidosis and tuberculosis include tuberculin skin test status, the presence of ocular surface disease, and the anatomic relationship between vasculitis and choroiditis.

The diagnosis of presumed ocular tuberculosis remains a clinical challenge with currently available diagnostic modalities. Although newer interferon-γ release assays can distinguish exposure to M. tuberculosis from the Bacille-Calmette-Guérin vaccine strain, they currently lack the specificity to distinguish between latent tuberculosis infection and active tuberculosis. Continued improvement in the currently available molecular diagnostic techniques including quantitative PCR may be valuable in our ability to establish an earlier etiologic diagnosis and institute appropriate antimycobacterial therapy.