Ocular Tuberculosis: A Case Series from a London Hospital

Background: Ocular TB is defined as an infection of Mycobacterium tuberculosis involving any part of the eye. Estimates of 1.4% of patients with pulmonary tuberculosis have ocular involvement and though rare, this presentation can have devastating consequences if not recognised. We present a case series of ocular TB diagnosed at London North West Healthcare trust which serves a multicultural community with the highest rates of TB infection in the UK. Methods and materials: Retrospective analysis of laboratory and medical records, radiology and microbiology results of patients with ocular TB identified from the London TB register from September 2012 to July 2019 from London North West Hospitals University NHS Trust. Results: 28 patients with ocular TB were identified: 23 uveitis (10 anterior uveitis, 6 posterior uveitis, 7 panuveitis), 1 maculopathy, 1 optic neuritis, 1 epislceritis, 1 orbital fibrovascular TB lesion and 1 retinal periphlebitis. All were presumptive diagnoses with only one having ocular microbiological samples obtained; which were negative. 54% of cases were female, average age at diagnosis 48 years (range 22 to 72). 89.3% were migrants; 29% African and 61% South Asian, particularly Indian (39%). Average time from symptoms presenting to treatment commencing was 186 days. Only 2 patients had evidence of TB at other sites; both extra-pulmonary (mediastinal and extra thoracic lymph nodes). 1 patient was HIV positive. Nine patients (32.6%) received steroids (3 eye drops and 6 systemic therapies). Nearly all patients had either a reactive Mantoux test (10) or Interferon Gamma Release Assay (17). Treatment duration was usually the standard 6 months (57%) followed by 9 months (19%), 12 months (19%) and 13 months (5%) with 2 patients lost to follow up. 19 patients (67.9%) were treated with ethambutol sparing regimens usually replacing with moxifloxacin. 1 patient had blindness as a long term sequaela of ocular TB. Conclusion: Our case series demonstrates that ocular tuberculosis frequently occurs in the absence of pulmonary tuberculosis and should be considered in all cases of uveitis in patients from endemic regions.