Sympathetic ophthalmia following penetrating trauma develops through which immunological mechanism, and the minimum time interval after injury before it can present is:
- A Type I IgE-mediated allergy to uveal antigens; minimum 24 hours
- B Type III immune complex deposition in uveal vasculature; minimum 1 week
- C NK cell-mediated cytotoxicity against stressed retinal photoreceptors; minimum 1 month
- D CD4+ T-cell mediated autoimmunity against sequestered uveal antigens (melanocyte antigens); minimum 2 weeks, usually >3 months ✓
Explanation
Sympathetic ophthalmia is a bilateral granulomatous panuveitis triggered by trauma (or surgery) to one eye. The mechanism involves release of sequestered uveal antigens (specifically melanocyte-associated antigens including S-antigen/retinal arrestin and IRBP) that are normally shielded from immune surveillance. CD4+ Th1 cells become sensitized and attack the uveal tissue of both eyes. The minimum interval is approximately 9–14 days, but most cases occur 3 weeks to 3 months after injury (80% within 1 year). Enucleation of the injured (exciting) eye within 2 weeks may prevent SO, but thereafter enucleation is controversial.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.