How do you differentiate between ocular involvement due to active tuberculosis versus latent infection in a patient with uveitis and suspected tuberculosis?

The type of ocular involvement (phenotype) is important to determine if the uveitis is related to active tuberculosis [like the presence of a single choroidal granuloma, serpiginous-like choroidopathy or choroiditis (unifocal or multifocal)] vs. a patient with recurrent unilateral anterior uveitis. Excluding other causes of uveitis like syphilis and sarcoidosis is also important. The detection of M. tuberculosis in ocular fluids or tissues is extremely difficult and PCR has low sensitivity so th...