A 28-year-old Indian female presents with floaters, photopsia, and blurred vision. Fundoscopy reveals vitritis inflammation with scattered retinal hemorrhages and cotton-wool spots. Anterior chamber is quiet. What is the most common infectious cause of posterior uveitis in India?

Explanation

## Most Common Infectious Cause of Posterior Uveitis in India **Key Point:** Tuberculosis is the most common infectious cause of posterior uveitis in India. TB can present as choroiditis, retinal vasculitis, or miliary TB with multiple choroidal tubercles. **High-Yield:** In endemic regions, TB accounts for 5–15% of all posterior uveitis cases. The presentation of vitritis inflammation with retinal hemorrhages and cotton-wool spots is consistent with TB retinal vasculitis. ### Infectious Causes of Posterior Uveitis — Epidemiology | Organism | Prevalence in India | Clinical Presentation | Key Diagnostic Feature | |----------|-------------------|----------------------|------------------------| | **Tuberculosis** | Most common | Retinal vasculitis, choroiditis, miliary TB | Mantoux +ve, chest imaging, AFB | | Toxoplasmosis | Common (but usually anterior) | Focal retinochoroiditis, "headlight in headlight" | Serology (IgG/IgM), imaging | | CMV retinitis | Rare (mainly AIDS) | Hemorrhagic retinitis, "pizza pie" appearance | CD4 <50, PCR, immunocompromised | | Acute retinal necrosis | Rare | Acute retinal necrosis, hemorrhage, vasculitis | HSV/VZV serology, PCR | **Clinical Pearl:** TB posterior uveitis presents as: - **Choroidal tubercles** — small, yellowish nodules at the choroid (miliary TB) - **Retinal vasculitis** — inflammation of retinal vessels with hemorrhages and cotton-wool spots - **Serpiginous choroiditis** — rare but characteristic serpentine pattern of choroidal inflammation - Quiet anterior chamber (unlike bacterial endophthalmitis) **Mnemonic — Posterior Uveitis Causes (TORCH + TB):** Toxoplasmosis, Other (syphilis, CMV), Rubella, Cytomegalovirus, Herpes simplex, **Tuberculosis** (most common in India). **Warning:** Toxoplasmosis is often cited as the most common cause of posterior uveitis globally, but in India, TB is more prevalent due to high endemicity. Do not confuse global epidemiology with Indian epidemiology. **Clinical Pearl:** The presence of retinal hemorrhages and cotton-wool spots with vitritis inflammation suggests vasculitis, which is highly characteristic of TB retinal vasculitis. Anterior chamber being quiet rules out acute bacterial endophthalmitis. **Tip:** Always obtain Mantoux test, chest X-ray, and ESR in any case of posterior uveitis in an Indian patient. TB serology and imaging should be part of the workup.