About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Commonest form of uveitis (~90%) — usually unilateral, acute onset
- Classic: painful red eye + photophobia + blurred vision + small/irregular pupil
- Slit-lamp: anterior chamber cells and flare, keratic precipitates, posterior synechiae
- Strong HLA-B27 association — ankylosing spondylitis, reactive arthritis, IBD
- Treatment: topical steroids (prednisolone 1%) + cycloplegic (cyclopentolate 1%) to prevent synechiae
Overview
Anterior uveitis (iritis/iridocyclitis) is inflammation of the iris and ciliary body. Most cases are idiopathic (38–88%), but important associations include HLA-B27-positive spondyloarthropathies, sarcoidosis, infections (HSV, VZV, syphilis, TB), and Behçet disease. The condition is typically acute and unilateral, though bilateral or chronic presentations should prompt investigation for systemic causes.
Epidemiology
Annual incidence approximately 12–17 per 100,000, most common in adults aged 20–50. HLA-B27 positivity confers a ~1% lifetime risk of anterior uveitis. Approximately 50% of patients experience recurrence. HLA-B27-positive disease typically presents more acutely but responds well to treatment.
Clinical Features
Symptoms
Unilateral eye pain — deep, aching, worse on focusing
Photophobia (even consensual — light in the unaffected eye causes pain in the affected eye)
Blurred vision
Excessive lacrimation
Red eye — circumcorneal (ciliary) injection
Floaters or significant visual loss suggests posterior involvement
Signs
Small (miotic) and possibly irregular pupil (posterior synechiae)
Circumcorneal (ciliary) injection
Anterior chamber cells and flare on slit-lamp (Tyndall effect)
Keratic precipitates (KPs) on corneal endothelium
Posterior synechiae — iris adheres to anterior lens capsule
Hypopyon in severe cases — consider Behçet or endophthalmitis
Investigations
First-line
Slit-lamp biomicroscopyESSENTIAL — demonstrates AC cells, flare, KPs, synechiae
Visual acuityTypically mildly reduced
IOPCan be raised or low
Second-line
HLA-B27If recurrent, bilateral, or associated joint symptoms
CRP/ESR, FBCAssess for systemic inflammation
Chest X-raySarcoidosis or TB screening
Serum ACEIf sarcoidosis suspected
Specialist
Syphilis serology, QuantiFERON-TB GoldExclude infectious causes in atypical cases
ANAIf JIA-associated uveitis suspected (children)
Management
NICE CKS — Uveitis + RCOphth guidelines1
Acute anterior uveitis
- Topical corticosteroid: prednisolone 1% or dexamethasone 0.1% — initially hourly, taper over 4–6 weeks
- Cycloplegic: cyclopentolate 1% TDS or atropine 1% BD — pain relief AND prevents/breaks synechiae
- Do NOT stop steroids abruptly — taper to prevent rebound
2
Referral
- Same-day or next-day ophthalmology referral
- Rheumatology referral if recurrent + joint symptoms
3
Recurrent or chronic uveitis
- Investigate for systemic cause
- Steroid-sparing immunosuppression: methotrexate, azathioprine, mycophenolate
- Adalimumab for refractory non-infectious uveitis (NICE TA460)
Complications
- Posterior synechiae: Can cause pupil block and secondary glaucoma
- Band keratopathy: Calcium deposits from chronic inflammation
- Cataract: From inflammation or prolonged steroids
- Cystoid macular oedema
- Secondary glaucoma
UKMLA Exam Tips
- 1Red eye + small irregular pupil + photophobia = anterior uveitis. Compare: AACG (mid-dilated fixed pupil), conjunctivitis (normal pupil)
- 2HLA-B27 = anterior uveitis + AS + reactive arthritis + psoriatic arthritis + IBD
- 3Consensual photophobia is classic — light in GOOD eye causes pain in affected eye
- 4Cycloplegic serves dual purpose: pain relief AND preventing synechiae
- 5Granulomatous uveitis (large "mutton fat" KPs) = sarcoidosis, TB, syphilis
- 6Hypopyon = Behçet disease or endophthalmitis
- 7Child with chronic anterior uveitis + ANA-positive = JIA
practicetest your knowledge on anterior uveitisApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — ophthalmology and beyond.
open q-bank