Strengths and weaknesses of diagnostic tools for tuberculous uveitis

Diagnostic criteria for tuberculous uveitis encompass exclusion of other known etiologies of uveitis, suggestive clinical history and signs, supportive systemic investigations, positive response to empiric antituberculosis treatment and evidence of Mycobacterium tuberculosis or its DNA in ocular fluids/tissues. Recent advances in diagnostic tools for tuberculous infection, including molecular biology techniques for detection of M. tuberculosis DNA and interferon-gamma release assays, have improved the specificity of the diagnosis and the ability to ascertain exposure to the infectious agent. However even with such advances, establishing the diagnosis of tuberculous uveitis remains a challenging issue because each of these available investigations has its strengths and limitations and tuberculous infection can present with clinical features of any type of extraocular or intraocular inflammation. This article critically analyzes the role of these tests in supporting the diagnosis of tuberculous uveitis and proposes a practical diagnostic approach, based on a judicious combination of these tests.