Uveitis and Ocular Immunology
Uveitis and ocular immunology asks you to classify inflammation with the SUN criteria and then link it to a systemic disease, while recognising the masquerade syndromes that punish a reflex steroid prescription.
Core rules
- SUN grading: anterior chamber cells 0 to 4+ in a 1 mm by 1 mm slit beam, with flare graded separately. Use the same slit-lamp settings at each visit.
- Anterior uveitis: HLA-B27, ankylosing spondylitis, reactive arthritis, inflammatory bowel disease, Behçet disease, herpes, sarcoidosis and lens-induced disease. Acute unilateral non-granulomatous inflammation with a fibrinous reaction favours HLA-B27.
- Intermediate uveitis: pars planitis, snowbanking and vitritis; check for sarcoidosis, multiple sclerosis and lymphoma.
- Posterior and panuveitis: toxoplasmosis (headlight-in-fog lesion), Behçet (occlusive vasculitis, hypopyon), Vogt–Koyanagi–Harada (bilateral serous detachments, pleocytosis), sympathetic ophthalmia after penetrating trauma.
- Treatment: topical steroid and cycloplegic for anterior disease; periocular or intravitreal steroid for intermediate; systemic steroid, methotrexate, azathioprine, mycophenolate or biologics for sight-threatening posterior disease.
- Before immunosuppression: screen for tuberculosis with chest radiography and interferon-gamma release assay, and for hepatitis B and C.
Worked example
A 27-year-old man has his third episode of a painful red right eye in 18 months. The pupil is small, there are 3+ cells and fibrin, and the left eye is quiet. He has morning back stiffness. The diagnosis is HLA-B27-associated acute anterior uveitis, likely linked to ankylosing spondylitis. You treat with topical prednisolone acetate and cyclopentolate, refer for rheumatological assessment, and explain that recurrences should be treated early. You do not start oral steroids for a first episode of moderate severity.
Traps
Failing to dilate the pupil, treating a masquerade lymphoma with steroids, and starting a biologic without tuberculosis screening.