IFNG and infection: A study conducted in Iraq showed high sensitivity and specificity of tuberculin sensitivity test with more than 14 mm induration.26 Many researchers recommend using combination of Mantoux test, interferon gamma release assays, and clinical signs to diagnose ocular tuberculosis.27,28,29,30 Ang et al.31 suggested that interferon assays should be preferred in areas where the prevalence of infection is low, and tuberculin skin test should be preferred where there is high prevalence of TB associated infection.