A 4-year-old female presented with vision decrease for the past 6 months. Examination of the anterior segment revealed cells 1+ and flare 2+. The iris was studded with diffuse nodules suggestive of granulomatous inflammation. Her tests for tuberculosis were positive. She was initiated on oral steroids and anti-tubercular therapy
Chronic recurrent anterior uveitis may be complicated with the development of posterior subcapsular cataract. In addition, the posterior synechiae may lead to pupillary block and secondary glaucoma. Band keratopathy and iris neovascularization are other associations in anterior segment disease.
Intermediate Uveitis
IOTB may also present as intermediate uveitis that has nonspecific presentation, but vitritis with snowballs and peripheral retinal phlebitis is common (Parchand et al. 2011). This phenotype is most commonly likely to be mistaken for pars planitis, a disease that has typical phenotype but is believed to be idiopathic.
A 30-year-old female presented with decreased vision in both eyes for the past 1 month (only left eye shown). Ocular examination revealed 1+ cellular reaction in the anterior chamber. (a) There was significant vitritis in both eyes. (b, c) Fluorescein angiography revealed early disc hyperfluorescence with late leakage and petalloid pattern of dye accumulation in the macula suggestive of cystoid macular edema. She was diagnosed as probable tubercular intermediate uveitis since her immunological and radiological investigations were positive. She received intravitreal dexamethasone depot injection in both eyes and anti-tubercular therapy
Posterior and Panuveitis
- 1.
Choroidal Tubercles/Tuberculoma:
Choroidal tubercles were the earliest sign described in IOTB, mostly in association with disseminated TB. They appear as round, small, multiple, well-defined lesions. Choroidal granulomas or tuberculomas or subretinal granulomas are larger in size, solitary, unilateral, and usually in the posterior pole with surrounding exudative retinal detachment (Gupta et al. 2015b; Singh et al. 2012).
- 2.
Serpiginous-like choroiditis (multifocal serpiginoid choroiditis):
Serpiginous-like choroiditis (SLC) typically affects young to middle-aged adults from TB-endemic areas such as India and immigrants in other countries such as UK (Bansal et al. 2012; Gupta et al. 2003). Unlike autoimmune serpiginous choroiditis, tubercular serpiginous-like choroiditis occurs at a younger age, associated with mild vitritis and is bilateral in majority of the cases (Nazari Khanamiri and Rao 2013). This entity may have different morphological patterns (Fig. 16.3) (Bansal et al. 2012).
- (a)
Placoid chorioretinitis: In this phenotype of IOTB, a diffuse plaque-like lesion is observed, which has a characteristic amoeboid pattern and active edge. The borders of the lesions are yellowish-white and elevated, whereas the center of the lesion is less elevated with pigmentary changes suggestive of a healing process in the center of the lesion.
- (b)
Multifocal choroiditis: This phenotype of IOTB presents with discrete lesions, yellowish-white in color with well-defined margins and slightly raised edges. The edges of these lesions are non-contiguous initially and show a wave-like progression over a period of 1–4 weeks and gradually become confluent.
- (c)
Mixed/Undetermined pattern: These lesions of IOTB present with overlapping features of both multifocal and placoid chorioretinitis. There have been descriptions of TB choroiditis lesions that may appear as other white dot syndromes such as ampiginous choroiditis.
- (a)
- 3.
Tubercular Subretinal Abscesses:
TB-related subretinal abscess appears distinct and more yellowish in color compared to a small choroidal granuloma. They usually have overlying retinal hemorrhages, and have a tendency to develop retinal angiomatous proliferation over a period of time.
Imaging Features of Posterior/Panuveitis
- 1.
Color Photography and Ultra-wide Field Imaging
In order to accurately study the morphology of the IOTB lesions, it is important to obtain color fundus photography at regular intervals. This greatly aids in the analysis of the fundus lesions and provides an objective assessment of change in the lesions over an extended period. Serial fundus photography (from acute stage to the stage of healing) is very useful in assessment of morphological evolution of the lesions (Bansal et al. 2012). Ultra-wide field (UWF) fundus imaging is a recent addition in the imaging modalities used for the assessment of various chorioretinal pathologies. Compared to conventional imaging (fundus photography and fluorescein angiography), UWF imaging systems aid in detection of additional features such as perivascular choroiditis, retinal vasculitis, and retinal neovascularization (Aggarwal et al. 2016). In addition, UWF imaging may be superior to conventional imaging in identifying peripheral paradoxical worsening, which may be otherwise missed on conventional imaging (Aggarwal et al. 2016).
- 2.
Fundus Autofluorescence
Studies have shown that fundus autofluorescence (FAF) is a very useful noninvasive imaging modality in the management of IOTB, specifically TB serpiginous-like choroiditis. Staged of lesions using FAF (Gupta et al. 2012) is as follows: active lesions demonstrate ill-defined hyper-autofluorescence throughout the lesions. Thus, the lesions have a diffuse, amorphous appearance (Stage 1). In the stage of early healing (Stage 2), a thin rim of hypo-autofluorescence is seen surrounding the lesion, which remains predominantly hyper-autofluorescent with a stippled pattern. With further healing, the lesion becomes predominantly hypo-autofluorescent (Stage 3) on FAF imaging. On complete healing, the lesions become uniformly hypo-autofluorescent without hyper-autofluorescent areas (Stage 4) (Gupta et al. 2012).
- 3.
Fluorescein Angiography
Fluorescein angiography (FA) is a very useful modality in the diagnosis and follow-up of patients with IOTB. TB choroiditis lesions appear hypofluorescent in the early phase and show hyperfluorescence in the late phase. Due to RPE damage and choriocapillaris atrophy, the areas of healing may demonstrate window defects (Bansal et al. 2012). Thus, FA is very helpful in demonstrating the activity of the lesions. In addition, complications of the disease such as inflammatory choroidal neovascularization may be detected using FA, though it may be very challenging in the absence of high index of suspicion (Bansal et al. 2016).
- 4.
Indocyanine Green Angiography
On Indocyanine green angiography (ICGA), active lesions of TB SLC remain hypofluorescence from early to late phase on ICGA. ICGA is very useful in detecting choriocapillaritis and presence of choriocapillaris hypoperfusion among patients with IOTB. Other changes of tubercular uveitis include presence of numerous hyperfluorescent spots, fuzzy appearance of choroidal vessels in the intermediate phase, and late choroidal hyperfluorescence due to dye leakage, which tends to regress after the completion of treatment with ATT and corticosteroids.
- 5.
Optical Coherence Tomography
Spectral-domain OCT, especially enhanced-depth imaging (EDI) OCT, has provided numerous insights into the pathogenesis of IOTB. OCT permits identification of peripapillary retinal atrophy, disruption of the photoreceptor and other outer retinal layers, thinning of the RPE, mild cystic changes as well as subretinal fibrosis in area of old choroidal neovascularization and marked attenuation of the interdigitation zone in the outer retina (Punjabi et al. 2008; Rifkin et al. 2015). TB choroiditis may also result in alteration of the ellipsoid and the myoid zones in the outer retina along with choriocapillaris thinning. Active edges of the lesions show localized, fuzzy area of hyper-reflectivity in the outer retinal layers involving the RPE, photoreceptor outer segment tips, external limiting membrane, and the outer nuclear layer without increased backscattering from the inner choroid. As the lesions begin to heal from the center, the hyper-reflective fuzzy areas begin to disappear and are replaced by irregular, hyper-reflective knobbly elevations of the outer retinal layers. Eventually, there is loss of RPE and outer retinal layers, and persistent increased reflectance from the choroid on OCT (Bansal et al. 2011).
With the introduction of advanced technologies such as EDI and swept-source (SS)-OCT, there has been tremendous advancement in the diagnostic capabilities in the field of IOTB. Recent introduction of OCT angiography, a dye-less noninvasive technique to obtain photographs of retinochoroidal endoluminal networks, has furthered our capabilities to understand the pathological involvement in IOTB.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
