Utility of routine chest radiography in ocular tuberculosis and sarcoidosis

BACKGROUND: Tuberculosis (TB) and sarcoidosis commonly present with pulmonary and ocular involvement. Routine chest radiography (CXR) is recommended in the workup for suspected intraocular TB (IOTB) or intraocular sarcoidosis (IOS); however, data on the utility of CXR in this setting are lacking.

METHODS: A post-hoc analysis was performed of a prospectively collected data set comprising 104 patients with uveitis of unknown cause. A pulmonologist and thoracic radiologist, blinded to the final diagnosis, independently reported these CXRs as being in keeping with TB or sarcoidosis.

RESULTS: CXRs were reported as normal/indeterminate (n = 88), probable/previous TB (n = 9) or possible/probable sarcoidosis (n = 8), with a 96% inter-observer concordance. CXRs were more often abnormal in IOS than in IOTB (5/8 vs. 5/34, P = 0.01). CXR had a sensitivity of 14.7%, specificity of 94.3%, positive predictive value (PPV) of 55.6% and negative predictive value (NPV) of 69.5% for IOTB, compared with a sensitivity of 62.5%, specificity of 96.9%, PPV of 62.5% and NPV of 96.9% for IOS. Overall diagnostic accuracy was 54.5% (58.1% in human immunodeficiency virus [HIV] positive participants) in the case of IOTB and 79.9% for IOS.

CONCLUSION: CXR had high specificity and NPV for IOS, and poor overall diagnostic accuracy for IOTB, including in the HIV-positive population.