Ocular tuberculosis: Where are we today?

Abstract

Diagnosis and management of ocular tuberculosis (OTB) poses a significant challenge. Mixed ocular tissue involvement and lack of agreement on best practice diagnostic tests together with the global variations in therapeutic management contributed to the existing uncertainties regarding the outcome of the disease. The current review aims to update recent progress on OTB. In particular, the Collaborative Ocular Tuberculosis Study (COTS) group recently standardized a nomenclature system for defining clinical phenotypes, and also proposed consensus guidelines and an algorithmic approach for management of different clinical phenotypes of OTB. Recent developments in experimental research and innovations in molecular diagnostics and imaging technology have provided a new understanding in the pathogenesis and natural history of the disease.

Keywords: Antitubercular therapy; COTS CON nomenclature; collaborative ocular tuberculosis study (COTS); etiopathogenesis; multimodal imaging; ocular tuberculosis; tubercular uveitis.

Figure 1

Diagnostic and therapeutic conundrum of ocular tuberculosis

Figure 2

(a) Right eye ultrawide field color fundus photograph of serpiginous-like choroiditis having an active edge with amoeboid spread and a healing center (better seen in the magnified square 1) (b) Right eye ultrawide field fundus autofluorescence showing hyperautofluorescent active edge

Figure 3

Ultrawide field color fundus photograph of a 38-year-old Indian man diagnosed with tubercular multifocal choroiditis Right eye multifocal inactive lesions distributed in the posterior pole and the periphery Left eye multifocal active lesions (arrow and circle), along with old healing lesions, involving the posterior pole and peripheral fundus. Both eyes show sequelae of healed retinal vascultitis, including peripheral ischemia and retinal neovascularization

Figure 4

(a) Ultrawide field color fundus photograph of the right eye of a 55-year-old Indian man with positive QuantiFERON-TB Gold diagnosed with tuberculoma. (b) EDI-OCT showing large homogenous, hyporeflective choroidal granuloma (star) with subretinal fluid and “contact sign” (arrow), defined as a localized area of adhesion between RPE–choriocapillaris and overlying neurosensory retina, surrounded by an area of exudative retinal detachment. (c) ICGA revealing hypofluorescent lesion in the early phase (c, left panel), remaining hypofluorescent in the late phase (c, right panel)

Figure 5

Ultrawide field color fundus photograph of a patient diagnosed with bilateral tubercular vasculitis, showing vascular sheathing involving the veins, with a characteristic perivascular patch of choroiditis in the superior temporal periphery (circle)

Figure 6

Ultrawide field fluorescein angiography of the same eye as in Figure 2 diagnosed with serpiginous-like choroiditis showing (a) hypofluorescence in the early phase and (b) hyperfluorescence in the late phase

Figure 7

Ultrawide field fluorescein angiography of the same patient in Figure 3 diagnosed with tubercular multifocal choroiditis Right eye Healed lesions show early and late transmission hyperfluorescence Left eye Active lesions (arrow and circle) that are hypofluorescent in the early phase (a), showing hyperfluorescence in the late phase (b), along with inactive scars showing early and late transmission hyperfluorescence. Both eyes show peripheral areas of capillary nonperfusion and retinal neovascularization

Figure 8

Ultrawide field fluorescein angiography of the same eye as in Figure 5 diagnosed with bilateral tubercular vasculitis showing bilateral vascular leakage and bilateral leakage into the cystoid spaces suggestive of cystoid macular edema

Figure 9

Ultrawide field indocyanine angiography of the same patient in Figure 3 diagnosed with tubercular multifocal choroiditis Right eye healed lesions, showing early and late hypofluorescence Left eye showing active lesions (arrow and circle), that are hypofluorescent in the early phase (a) and remain hypofluorescent in the late phase (b), with fuzzy margins suggestive of activity; and healed lesions, showing early and late hypofluorescence with more discrete margins