Background: Tuberculosis (TB) affects all ages resulting in morbidity in multiple organ systems. This study was performed to determine pattern of posterior uveitis, incidence of visual loss, role of aqueous humour analysis in systemic tuberculosis and its correlation with ocular and laboratory investigations.
Materials and Methods: A retrospective study on 200 patients with systemic tuberculosis over 2 years. Laboratory workup consisted of tuberculin test, chest x-ray, polymerase chain reaction, and interferon gamma assay. Blood and ocular sample analysis with ancillary ophthalmic investigations were performed.
Results: Incidence of uveitis in TB was 32%, visual loss in 7% and the initial presentation in 12%. Mean age of onset was 38 years (SD+/- 5). Uveitis was due to active systemic TB in 12% and immune response in 75% which was statistically significant (p=0.02). Etiology was pulmonary TB in 21% and extrapulmonary TB in 4%. Posterior uveitis occurred in 49 patients (77%) and was the most common (p=0.01.)
Chest x-rays revealed lung infiltrates, hilar lymphadenopathy, and calcification in 15% of patients. Mantoux was positive in 72% and positive PCR in 37% and positive aqueous humour analysis PCR results ranged from 71% to 96%. Overall, systemic investigations were positive in 72% of patients. Improvement was observed within 6 months in 87% of patients. Vision improvement or complete resolution occurred in 78% with ATT and corticosteroids.
Conclusion: Clinical suspicion guided by combination of investigations provides accurate diagnosis. In diagnostic dilemmas, when investigations are inconclusive, PCR performed on ocular samples are reliable and confirmatory. We recommend a multidisciplinary approach in the management of tuberculosis in the active stage, during and after treatment.
Keywords: Posterior uveitis, Tuberculosis, Vitritis, anti-tuberculosis treatment, Vasculitis.
