Tubercular Retinitis: Clinical Spectrum and Multimodal Imaging Features of an Insufficiently Characterized Entity

Area of Science:

• Ophthalmology
• Infectious Diseases
• Retinal Imaging

Background:

• Ocular tuberculosis (OTB) commonly affects the posterior segment, often presenting as choroiditis.
• Tubercular retinitis (TBR) is a rare and less understood manifestation of OTB.
• Differentiating TBR from other chorioretinal lesions in OTB is crucial for appropriate management.

Purpose of the Study:

• To define the clinical spectrum of tubercular retinitis (TBR).
• To analyze multimodal imaging characteristics of TBR lesions.
• To differentiate TBR from similar-appearing chorioretinal lesions in ocular tuberculosis (OTB).

Main Methods:

• Retrospective case series of patients with suspected retinitis.
• Analysis of clinical data, fundus findings, and multimodal imaging (fundus photography, FFA, ICGA, OCT).
• Diagnosis of OTB based on Collaborative Ocular Tuberculosis Study (COTS) criteria; treatment with antitubercular therapy (ATT) and corticosteroids.

Main Results:

• Eight patients presented with 37 lesions; 25 (67.6%) were classified as TBR (purely retinal) and 12 (32.4%) as tubercular retinochoroiditis (TBRC) (involving choroid/RPE).
• Occlusive retinal vasculitis was observed in all eyes.
• Multimodal imaging revealed distinct features: 'moat sign' on FFA for TBR, intraretinal hyper-reflectivity on OCT for TBR, and outer retinal/RPE changes with choroidal shadowing for TBRC. TBR lesions healed without scarring, while TBRC lesions showed scarring and RPE disruption.

Conclusions:

• Posterior segment OTB spectrum includes intraretinal inflammation (TBR) and retinochoroiditis (TBRC), often associated with retinal vasculitis.
• Clinical examination and multimodal imaging are key to identifying tubercular etiology.
• Distinct imaging features allow differentiation between TBR and TBRC, aiding in diagnosis and management.