A previously healthy 30-year-old woman develops severe unilateral eye pain, blurred vision, and redness over 4 days. Examination shows prominent anterior chamber and vitreous inflammation, patchy peripheral necrotising retinitis with sharp borders, and occlusive retinal vasculitis. The most common causative agent is:

• A Varicella-zoster virus ✓
• B Cytomegalovirus
• C Treponema pallidum
• D Toxoplasma gondii

Explanation

This is acute retinal necrosis, a necrotising herpetic retinochoroiditis defined by one or more foci of retinal necrosis with discrete borders, rapid progression, occlusive vasculopathy, and prominent inflammatory reaction. Varicella-zoster virus is the most frequent isolate, followed by herpes simplex virus. CMV retinitis occurs in profound immunosuppression and lacks such dense occlusive vasculitis, which kills option B.

Reference: Ryan's Retina, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.