A 30 year old male came with complains of unilateral blurred vision with floaters since 15 days. On examination, AC flare and cells were seen with 'headlight in fog' appearance on indirect ophthalmoscopy. Also, a single inflammatory focus of fluffy retinochoroiditis lesion is seen. What is the diagnosis?

Ans. is 'b' i.e., Toxoplasmosis chorioretinitis * Toxoplasmosis is caused by Toxoplasma gondii, an obligate intracellular protozoan.* Symptoms: Unilateral acute or subacute onset of floaters, blurring and photophobia.* 'Spill-over' anterior uveitis is common. It may be granulomatous or resemble Fuchs uveitis syndrome; elevated IOP may develop.* A single inflammatory focus of fluffy white retinitis or retinochoroiditis associated with a pigmented scar ('satellite lesion') is typical. Lesions tend to involve the posterior pole.# Vitritis may be severe and impair fundus visualization. 'Headlight in the fog' is the classic description of a white retinal inflammatory nidus viewed through vitritis.# Extensive and fulminant retinal involvement is generally confined to the immunocompromised.