Following unilateral perforating injury to the right eye with uveal tissue prolapse, sympathetic ophthalmia can develop in the fellow eye. The histological hallmark of sympathetic ophthalmia in the excised sympathizing eye is:

• A Suppurative choroiditis with PMN infiltration
• B Diffuse granulomatous uveal inflammation with epithelioid and giant cells sparing the choriocapillaris (Dalen-Fuchs nodules) ✓
• C Focal necrotizing retinitis with multinucleated giant cells
• D Non-granulomatous lymphocytic panuveitis without choroidal involvement

Explanation

Sympathetic ophthalmia is a T-cell mediated autoimmune reaction against uveal antigens (RPE melanocytes, photoreceptor interstitial retinol-binding protein) unmasked after perforating injury. The histological hallmark is diffuse granulomatous panuveitis with epithelioid cell clusters and Langhans giant cells throughout the uveal tract, sparing the choriocapillaris — this choriocapillaris sparing is pathognomonic. Dalen-Fuchs nodules are focal accumulations of RPE cells and macrophages between Bruch's membrane and RPE seen in 25-35% of cases. Prevention requires enucleation of the exciting eye within 2 weeks of injury; after 2 weeks, risk of sympathetic ophthalmia is too high to guarantee enucleation prevents it.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.