Painful red eye with photophobia, miotic pupil, and cells/flare in the anterior chamber; treat with cycloplegic and topical steroid; investigate for HLA-B27 disease.
Also known as: anterior uveitis, iritis, iridocyclitis, acute anterior uveitis, HLA-B27 uveitis
Overview
Inflammation localized primarily to the anterior segment of the uveal tract — the iris (iritis) and ciliary body (iridocyclitis). Classified by onset (acute, recurrent, chronic), laterality, and granulomatous vs nongranulomatous appearance. Most common form of uveitis (about 75% of cases).
Epidemiology
Incidence 8-12 per 100,000 per year. Peak age 20-50, slight male predominance. HLA-B27 is positive in about 50% of acute anterior uveitis cases; the lifetime risk in HLA-B27 carriers is 1-2%.
Try two board-style Anterior Uveitis questions
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Question 1EENTMedium
A 28-year-old man presents with a 2-day history of a painful, red right eye with photophobia and blurred vision. He reports a dull brow ache and says bright light makes the pain worse. He has had a similar episode in the same eye a year ago and notes several months of low back stiffness that improves with activity. On examination, visual acuity is mildly reduced. There is perilimbal redness with deeper vessel injection, and the pupil is small and slightly irregular. Slit-lamp examination shows cells and flare in the anterior chamber with fine keratic precipitates on the corneal endothelium. Fluorescein staining is negative. Which of the following is the most likely diagnosis?
AHerpes simplex keratitis
BAngle-closure glaucoma
CBacterial conjunctivitis
DAcute anterior uveitis
Reveal answer & full explanation
Correct answer: D — Acute anterior uveitis
AHerpes simplex keratitis
BAngle-closure glaucoma
CBacterial conjunctivitis
DAcute anterior uveitis✓
Why Acute anterior uveitis is correct
The triad of a painful red eye with photophobia, ciliary (circumlimbal) flush, and a miotic, slightly irregular pupil from ciliary spasm is the classic anterior uveitis presentation.
Cells and flare in the anterior chamber on slit-lamp exam are diagnostic, and fine (nongranulomatous) keratic precipitates on the corneal endothelium support the diagnosis. No cells, no uveitis.
Recurrent unilateral acute anterior uveitis in a young man with inflammatory low back pain that improves with activity points to HLA-B27-associated disease (ankylosing spondylitis spectrum).
Why the others are wrong
Angle-closure glaucoma causes severe pain with headache, nausea, and halos, a fixed mid-dilated pupil, corneal edema, and markedly elevated intraocular pressure; the small, irregular pupil and anterior-chamber cells here argue against it.
Herpes simplex keratitis produces a dendritic corneal lesion that stains with fluorescein and reduced corneal sensation, but fluorescein staining is negative here.
Bacterial conjunctivitis causes purulent discharge and a papillary conjunctival reaction with a normal pupil, no anterior-chamber cells, and no true photophobia.
Question 2EENTMedium
A 29-year-old man presents with 2 days of aching pain, redness, and light sensitivity in his right eye, along with blurred vision. He reports a similar episode in the same eye last year and has had intermittent low back pain that improves with exercise. Visual acuity is mildly reduced on the right. Examination shows perilimbal redness and a small, somewhat irregular pupil. Intraocular pressure is normal, and fluorescein staining shows no corneal epithelial defect. Which of the following additional findings is most likely on examination?
AA branching dendritic lesion that stains with fluorescein
BLeukocytes and protein layered in the anterior chamber
CA fixed mid-dilated pupil with elevated intraocular pressure
DA follicular conjunctival reaction with a watery discharge
Reveal answer & full explanation
Correct answer: B — Leukocytes and protein layered in the anterior chamber
AA branching dendritic lesion that stains with fluorescein
BLeukocytes and protein layered in the anterior chamber✓
CA fixed mid-dilated pupil with elevated intraocular pressure
DA follicular conjunctival reaction with a watery discharge
Why Leukocytes and protein layered in the anterior chamber is correct
Anterior uveitis is a clinical diagnosis confirmed on slit-lamp examination: breakdown of the blood-aqueous barrier lets leukocytes (cells) and protein (flare) leak into the anterior chamber, and this is the defining finding.
The recurrent, unilateral, painful red eye with ciliary (perilimbal) flush, a small irregular pupil, and inflammatory back pain that improves with exercise fits HLA-B27-associated acute anterior uveitis, which warrants HLA-B27 testing and rheumatology referral.
Why the others are wrong
A fixed mid-dilated pupil with elevated intraocular pressure describes acute angle-closure glaucoma; here the pupil is small (miotic from ciliary spasm) and the intraocular pressure is normal.
A branching dendritic lesion that stains with fluorescein defines herpes simplex keratitis; fluorescein staining showed no epithelial defect, excluding it.
A follicular conjunctival reaction with a watery discharge points to viral conjunctivitis, which causes minimal pain and no true photophobia or anterior chamber cells.
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Ocular trauma, recent intraocular surgery (sterile postoperative uveitis)
Idiopathic (about one-third of cases)
Pathophysiology
Breakdown of the blood-aqueous barrier permits leukocyte and protein leak into the anterior chamber. Inflammatory mediators released by ciliary body and iris produce ciliary spasm (pain, miosis, photophobia), exudation of cells (cells in AC) and protein (flare), and may deposit on the corneal endothelium (keratic precipitates). Chronic or recurrent inflammation causes posterior synechiae (iris adhesions to lens) and secondary glaucoma.
Conjunctivitis — Discharge, papillary or follicular reaction, no anterior chamber cells, no photophobia (or mild)
Episcleritis / scleritis — Sectoral redness, deep ache (scleritis); scleritis often associated with systemic disease and threatens vision
Endophthalmitis — Acute severe pain and vision loss after surgery or trauma; hypopyon, vitritis; emergency
Posterior uveitis or panuveitis — Floaters, decreased vision; cells in vitreous; chorioretinal lesions on fundus exam
Diagnostic workup
Diagnostic criteria
Clinical diagnosis by slit-lamp findings (cells and flare in the anterior chamber). Standardization of Uveitis Nomenclature (SUN) grading is used for cell and flare quantification.
Labs
First episode of unilateral acute anterior uveitis without systemic features may need NO workup
If recurrent, bilateral, granulomatous, or with systemic features: CBC, ESR, CRP, ACE, lysozyme, HLA-B27, RPR/treponemal, QuantiFERON-TB, ANA, urinalysis, Lyme serology if exposure
Chest X-ray or CT chest for sarcoid and TB screening
Sacroiliac imaging or MRI if back pain to assess for ankylosing spondylitis
Anterior chamber tap with PCR (HSV, VZV, CMV) for atypical or chronic cases
Topical cycloplegic — cyclopentolate 1%, homatropine 5%, or atropine 1% — to relieve ciliary spasm and prevent posterior synechiae
Topical corticosteroid — prednisolone acetate 1% every 1-2 hours initially, tapered over weeks; difluprednate 0.05% is an alternative potent steroid
Treat underlying cause if identified (antivirals for HSV/VZV uveitis, antibiotics for syphilis, anti-TB for tuberculosis)
Urgent ophthalmology referral within 24 hours
Monitor IOP at every visit — both inflammatory glaucoma and steroid-induced ocular hypertension can occur
Second-line / adjunct
Periocular or intravitreal corticosteroid injection (triamcinolone, dexamethasone implant) for severe or non-responsive disease
Systemic corticosteroid for bilateral severe or sight-threatening inflammation
Immunomodulatory therapy (methotrexate, azathioprine, mycophenolate, cyclosporine) for chronic recurrent disease
TNF-alpha inhibitors (adalimumab is FDA-approved for noninfectious uveitis; infliximab off-label) for HLA-B27-related, JIA-associated, or Behcet uveitis
Laser or surgical synechiolysis for refractory synechiae
Complications
Posterior synechiae with pupillary block and secondary angle-closure glaucoma
Cataract (from inflammation and from chronic steroid use)
Glaucoma (inflammatory, steroid-induced, or angle-closure)
Cystoid macular edema
Band keratopathy in chronic disease
Hypotony with phthisis in chronic uncontrolled inflammation
Vision loss
PANCE pearls
Cells in the anterior chamber on slit-lamp examination clinch the diagnosis — no cells, no uveitis.
Always dilate the pupil with a cycloplegic — both for synechiae prevention and to allow posterior segment examination.
Recurrent acute anterior uveitis, especially in young men with low back pain, should prompt HLA-B27 testing and rheumatology referral.
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