Ophthalmology · Anterior Uveitis
The facts most likely to be tested
Iritis presents with unilateral eye pain, photophobia, tearing, and a decreased visual acuity.
Slit-lamp examination reveals cells and flare in the anterior chamber, which is the hallmark of anterior uveitis.
Physical examination findings include a ciliary flush (limbal injection) and a constricted, non-reactive pupil (miosis).
Iritis is strongly associated with HLA-B27 positive conditions, most notably ankylosing spondylitis, reactive arthritis, and psoriatic arthritis.
The presence of keratic precipitates on the corneal endothelium is a classic sign of chronic or granulomatous inflammation.
First-line treatment for non-infectious iritis is topical corticosteroids to reduce inflammation and cycloplegic agents to prevent synechiae formation.
Failure to treat iritis can lead to permanent vision loss due to complications like secondary glaucoma, cataracts, or cystoid macular edema.
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A 28-year-old male presents with 3 days of left eye pain, blurred vision, and significant photophobia. He reports a history of chronic low back pain that improves with exercise. On physical exam, there is a ciliary flush around the limbus. Slit-lamp examination demonstrates cells and flare in the anterior chamber and a small, irregular pupil.
What is the most likely diagnosis and the most appropriate initial management?
Anterior uveitis (iritis); topical corticosteroids and cycloplegic agents.
The patient's presentation of unilateral eye pain, photophobia, and ciliary flush, combined with a history suggestive of ankylosing spondylitis (HLA-B27 association), is classic for iritis.
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High yield triage
Etiology / Epidemiology
Associated with HLA-B27 conditions like ankylosing spondylitis, reactive arthritis, and IBD.
Clinical Manifestations
Unilateral ciliary flush, photophobia, and cells and flare on slit lamp exam.
Diagnosis
Slit lamp examination is the gold standard to visualize anterior chamber inflammation.
Treatment
Topical corticosteroids are first-line; never use topical steroids without ruling out herpes simplex.
Prognosis
Risk of synechiae formation; requires urgent ophthalmology referral to prevent permanent vision loss.
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Epidemiology & Etiology
Iritis, or anterior uveitis, is frequently idiopathic but strongly linked to HLA-B27 seropositive spondyloarthropathies. Other triggers include sarcoidosis, Behçet disease, and infectious etiologies like syphilis or tuberculosis. It is the most common form of uveitis, typically presenting in young to middle-aged adults.
Pertinent Anatomy
The iris and ciliary body comprise the anterior uvea. Inflammation here disrupts the blood-aqueous barrier, leading to the leakage of protein and white blood cells into the anterior chamber.
Pathophysiology
Inflammatory mediators cause vasodilation of the limbal vessels, resulting in the characteristic ciliary flush. Breakdown of the blood-aqueous barrier allows protein exudation, termed flare, and leukocyte infiltration, termed cells. If untreated, fibrin deposition leads to the formation of synechiae (adhesions between the iris and lens or cornea).
Clinical Manifestations
Patients present with acute, unilateral eye pain, photophobia, and blurred vision. The hallmark finding is ciliary flush (circumlimbal injection). Slit lamp exam reveals cells and flare in the anterior chamber. Red flags include severe pain, decreased visual acuity, or irregular pupil shape, which may indicate synechiae.
Diagnosis
The slit lamp examination is the gold standard for diagnosis, revealing inflammatory cells and protein flare in the anterior chamber. A tonometry reading may show low or high intraocular pressure. Workup for systemic disease is indicated for recurrent or bilateral cases, focusing on HLA-B27 testing and chest X-ray for sarcoidosis.
Treatment
Management centers on topical corticosteroids (e.g., prednisolone acetate) to reduce inflammation. Cycloplegics (e.g., homatropine) are used to relieve pain and prevent synechiae. Contraindications include the use of steroids in the presence of an active herpes simplex infection, which can cause corneal melting.
Prognosis
Most cases resolve with prompt treatment, but complications like secondary glaucoma, cataract formation, and cystoid macular edema can occur. Patients must be monitored for synechiae formation, which can permanently distort the pupil and impair vision.
Differential Diagnosis
Conjunctivitis: diffuse redness, no photophobia, no ciliary flush
Acute Angle-Closure Glaucoma: fixed mid-dilated pupil, steamy cornea, high IOP
Keratitis: corneal staining with fluorescein, foreign body sensation
Scleritis: severe boring pain, blue-violet hue, tender to palpation
Subconjunctival Hemorrhage: painless, focal blood patch, no vision change