Sympathetic Ophthalmia

Sympathetic ophthalmia (SO) is a bilateral, diffuse, granulomatous panuveitis following penetrating injury or intraocular surgery to one eye (the exciting eye), involving the fellow eye (the sympathising eye). It is rare (0.2 to 0.5 percent after penetrating trauma and about 0.01 percent after intraocular surgery, particularly vitreoretinal surgery) but potentially blinding.

• Mechanism: T-cell-mediated autoimmunity against uveal and retinal antigens (melanocytes, retinal S-antigen) exposed after uveal tissue breach.
• Onset: about 65 percent within 3 months of injury, 90 percent within 1 year; it may be as early as 5 days or as late as decades.
• Risk factors: uveal prolapse, delayed wound repair, multiple surgeries, retained uveal tissue in wounds, vitrectomy, glaucoma drainage and cyclodestructive surgery, ocular tumour irradiation.

• Sympathising eye: blurred vision (loss of accommodation, near vision first), photophobia, pain, redness, floaters.
• Exciting eye: persistent inflammation after injury, with pain and poor healing.
• Signs: granulomatous anterior uveitis with mutton fat keratic precipitates, iris nodules, synechiae, vitritis, multifocal yellow white choroidal infiltrates (Dalen-Fuchs nodules), choroidal thickening, optic disc oedema, exudative retinal detachment.
• Chronic: depigmentation (sunset glow), sympathetic uveitis scars, cataract, glaucoma, subretinal fibrosis, choroidal neovascularisation.
• Systemic features similar to Vogt-Koyanagi-Harada disease may occur (headache, vitiligo, poliosis, hearing loss) but are less common.

• Clinical, based on a history of penetrating injury or surgery to the other eye with bilateral granulomatous panuveitis; no specific test.
• Fluorescein angiography: multiple pinpoint leaks at retinal pigment epithelium, late pooling and disc staining; indocyanine green angiography: hypofluorescent spots; optical coherence tomography: subretinal fluid, thickened choroid; B-scan choroidal thickening.
• Exclude infection (syphilis, tuberculosis, endophthalmitis), phacoantigenic uveitis, sarcoid, lymphoma, and VKH disease (no history of trauma).
• Histology of enucleated exciting eye shows diffuse granulomatous uveitis with epithelioid cells and giant cells, sparing the choriocapillaris.

• Prevention: meticulous early primary repair of penetrating injury (within 24 hours), removal of prolapsed uveal tissue, and prompt treatment of postoperative inflammation. Evisceration or enucleation of a hopelessly damaged exciting eye within 2 weeks of injury may reduce the risk, but is not routinely recommended when the eye has any visual potential, and does not alter the course once SO has begun.
• Acute treatment:
  • High dose corticosteroid: intravenous methylprednisolone 1 g daily for 3 days, then oral prednisolone 1 to 1.5 mg/kg daily (60 to 80 mg), tapered slowly over 6 to 12 months.
  • Topical prednisolone acetate 1 percent every 1 to 2 hours and atropine 1 percent twice daily; periocular triamcinolone 40 mg as adjunct.
• Early steroid sparing agents (within weeks): ciclosporin 3 to 5 mg/kg daily, mycophenolate mofetil 1 to 1.5 g twice daily, azathioprine 2 mg/kg daily, methotrexate 15 to 25 mg weekly, or adalimumab 80 mg then 40 mg every 2 weeks, infliximab 5 mg/kg for refractory cases. Treat for at least 1 to 2 years.
• Complications: cataract extraction after at least 3 months of quiet inflammation, glaucoma surgery, anti-VEGF (bevacizumab 1.25 mg) for choroidal neovascularisation.
• Prognosis: about 60 to 70 percent retain vision of 6/12 or better with early aggressive treatment; the sympathising eye may recover better than the exciting eye.
• Monitor every 2 to 4 weeks initially for relapse, and for treatment toxicity.