Case of the Month

Edited by Robert N. Johnson, MD

Case History:

24 year old Chinese male patient with no previous medical or surgical history presents for evaluation of severe left vision loss for 1 week. His history was negative for substance abuse or sexually transmitted infections. He immigrated from China 5 months prior to presentation.

On examination, best corrected visual acuity was 20/25 and 20/250-2 in right and left eyes, respectively. Intraocular pressure was 12 and 14. Anterior segment exam was unremarkable. Posterior segment exam revealed trace vitreous cell, disc hyperemia, macular edema with subretinal fluid, and retinal pigment epithelial changes along the superotemporal arcade. Multiple yellow outer retinal/choroidal lesions were note in the macula and the superior and inferior mid periphery (Figure 1). Irregular fluorescence was noted on fluorescein angiography (Figure 2) with late leakage. ICG angiography showed multiple areas of hypocyanescent lesions (Figure 3).

Differential Diagnosis

Non-infectious inflammations: Sarcoidosis, Serpiginous Choroidopathy, APMPPE

infectious causes: Syphilis, Tuberculosis, DUSN

Masquerade syndromes: lymphoma, leukemia

Additional History and Diagnosis:

Patient was started on topical steroids, while awaiting the results of a directed work up that included chest x-ray, ACE, lysozyme, Quantiferon Gold, RPR, FTA-Abs, CBC, ESR and CRP. Three days later, patient’s serum analysis was positive only for QuantiFERON Gold. Patient’s chest x-ray returned with a normal read. Given the exam findings, patient was diagnosed with disseminated tuberculous chorioretinitis of the left eye.

Treatment and Outcome:

Patient was started on Isoniazid, Rifampicin, Pyrazinamide and Ethambutol, followed by 60 mg oral prednisone one week later. The steroid was tapered by 10 mg every week until the dose reached 10 mg/day. Ten days later, significant improvement in the lesions in the posterior fundus was noted, but active lesions were present inferiorly (Figure 4). By two months, substantial improvement was present, but a small area of resolving inflammation was present superiorly (Figure 4). Complete resolution of inflammatory activity at the outer retinal and choroidal lesions was noted by 3 months (Figure 6). Patient’s best corrected visual acuity improved to 20/30.

Figure 4: Color photo montage of the left eye showing some improvement of the lesions in the posterior pole, but active lesions inferiorly and superiorly.

Figure 5: Fundus color montage of the left eye. Substantial improvement in the areas of chorioretinitis is seen. There is still an area of activity superiorly.

Figure 6: Wide-field color photo of the left eye. Note that the lesions have become inactive with wide-spread chorioretinal scarring.

Discussion:

Approximately a quarter of the world’s population is infected with Mycobacterium tuberculosis (TB).¹ In 2018, the world health organization (WHO) reported 10 million cases of active TB disease. Geographically, most TB cases in 2018 were in the WHO regions of South-East Asia (44%), Africa (24%) and the Western Pacific (18%), with smaller percentages in the Eastern Mediterranean (8%), the Americas (3%) and Europe (3%).¹ India alone accounted for 27% of all cases, with China (9% a distant second.1 In the United States and most Western European countries, the majority of cases occur in foreign-born residents and recent immigrants from countries in which tuberculosis is endemic.¹

Ocular tuberculosis can affect all parts of the eye. In TB-endemic Northern India, Amod Gupta et al found that suggestive clinical signs in eyes with intraocular TB (IOTB) include broad posterior synechiae, retinal perivasculitis with or without discrete choroiditis/scars and often with capillary non-perfusion, multifocal serpiginoid choroiditis (MSC), choroidal or optic disc granuloma(s), and optic neuropathy. Retinal perivasculitis and MSC, in particular, have been reported to have positive predictive values of 90% or greater.^2,3 Amod Gupta el al suggest in a later paper that IOTB can be classified as “confirmed, “probable” or “possible.” A confirmed diagnosis can be made in patients whom other causes of uveitis have been excluded, and have at least one clinical sign of IOTB and microbiological confirmation of TB from ocular fluids or tissues. “Probable IOTB” can be used in patients with active uveitis, but no microbiological confirmation when: (1) other causes of uveitis have been excluded; (2) at least one suggestive clinical sign of IOTB is present; (3) there is evidence of pulmonary or extrapulmonary TB; and (4) there is either a documented TB exposure history OR immunological evidence of TB infection – such as a positive TST or IGRA. Lastly, “Possible IOTB” would require one or more similarly suggestive clinical findings in addition to EITHER direct evidence of pulmonary or extrapulmonary TB OR exposure history and TST/IGRA evidence of prior exposure, but not both.⁴

The Who recommends 6 months of therapy anti-TB treatment (ATT), starting with rifampin, isoniazid, ethambutol, and pyrazinamide for 8 weeks, and then only rifampin and isoniazid the next 16 weeks for drug-susceptible pulmonary TB disease.⁵ However, a consensus does not exist regarding management of IOTB. Lou et al. report the results of two international surveys of the approach to diagnosis and treatment of IOTB – one completed by 87 members of the American Uveitis Society (AUS), most of whom were from either the US or Europe, and a second by an expanded group of 143 participants, nearly half of whom were from the developing world. Overall, 86% of respondents indicated that ATT should be continued for six months or more, with roughly half treating for nine to 12 months. The concurrent use of oral corticosteroids was recommended by approximately 50 and 25% of respondents from the developing and developed world, respectively.^6,7

References:

1. Global Tuberculosis Report 2019, World Health Organization (https://www.who.int/tb/publications/global_report/en/)
2. Gupta A, Bansal R, Gupta V, et al. Ocular signs predictive of tubercular uveitis. Am J Ophthalmol. 2010;149:562–570
3. Emmett T. Cunningham Jr, Sivakumar R. Rathinam, Thomas A. Albini, Soon-Phaik Chee, Manfred Zierhut. (2015) Tuberculous Uveitis. Ocular Immunology and Inflammation 23:1, pages 2-6.
4. Gupta A, Sharma A, Bansal R, Sharma K. Classification of intraocular tuberculosis. Ocul Immunol Inflamm. 2015;23:7–3
5. Guidelines for treatment of drug-susceptible tuberculosis and patient care 2017 update (https://www.who.int/tb/publications/2018/latent-tuberculosis-infection/en/)
6. Lou SM, Larkin KL, Winthrop K, Rosenbaum JT, and members of Uveitis Specialists Study Group. Lack of consensus in the diagnosis and treatment for ocular tuberculosis among uveitis specialists. Ocul Immunol Inflamm. 2015;23:25–31
7. Lou SM, Montgomery P, Winthrop K, et al. Diagnosis and treatment for ocular tuberculosis among uveitis specialists: The international perspective. Ocul Immunol Inflamm. 2015;23:32–39.