Anterior Uveitis (Iritis)

Anterior uveitis is inflammation at the front of the eye - primarily the iris (iritis) and sometimes the ciliary body (iridocyclitis), with inflammatory cells visible in the anterior chamber. It is the most common form of uveitis, accounting for roughly 75% of cases overall. Most episodes are acute, painful, and respond well to topical steroids, but recurrent or chronic anterior uveitis can be the eye manifestation of a systemic autoimmune or infectious disease that needs identifying.

Symptoms

• Eye pain - deep, aching, often worse with light
• Photophobia - intense light sensitivity, often the dominant complaint
• Red eye with ciliary flush (perilimbal redness) more pronounced than diffuse conjunctival redness
• Blurred vision from inflammatory cells in the anterior chamber
• Tearing with no significant discharge
• Headache on the affected side in some patients
• Usually unilateral in acute cases; bilateral involvement is more common in chronic and granulomatous forms

Symptoms typically develop over hours to days. The combination of red, painful, photophobic eye with blurred vision is a classic clinical presentation, but milder and atypical cases occur.

Subtypes

Acute Anterior Uveitis

• Sudden onset
• Symptoms last 6 weeks or less per episode
• Often unilateral
• HLA-B27-associated cases are typical

Chronic Anterior Uveitis

• Insidious onset, often without dramatic symptoms
• Lasts 3 months or longer
• Often bilateral
• Associated with juvenile idiopathic arthritis (JIA), sarcoidosis, Fuchs heterochromic iridocyclitis

Granulomatous vs. Non-Granulomatous

• Granulomatous - large "mutton-fat" keratic precipitates, iris nodules; sarcoidosis, TB, syphilis, sympathetic ophthalmia, Vogt-Koyanagi-Harada. Herpetic uveitis is usually non-granulomatous but can occasionally show granulomatous features (especially zoster)
• Non-granulomatous - fine KPs, no iris nodules; HLA-B27 spectrum, herpetic, idiopathic

Causes

Idiopathic (~50%)

No identifiable systemic cause despite full workup.

HLA-B27 Spectrum

• Ankylosing spondylitis
• Reactive arthritis
• Inflammatory bowel disease
• Psoriatic arthritis

HLA-B27 is positive in approximately 40-60% of patients with recurrent acute non-granulomatous unilateral anterior uveitis.

Infectious

• Herpes simplex and herpes zoster keratouveitis
• Toxoplasmosis - usually with retinal lesion
• Syphilis - a "masquerader" that can produce many uveitis patterns
• Lyme disease, tuberculosis
• Cytomegalovirus anterior uveitis - typically unilateral, often with elevated IOP and stellate or coin-shaped KPs; CMV has been implicated in a subset of patients with Posner-Schlossman syndrome (glaucomatocyclitic crisis) and in Fuchs-like uveitis

Systemic Inflammatory

• Sarcoidosis
• Behcet disease
• Juvenile idiopathic arthritis (often asymptomatic, screened by routine slit lamp)
• Vogt-Koyanagi-Harada disease

Other

• Trauma
• Post-surgical
• Drug-induced (rifabutin, cidofovir, bisphosphonates)

Diagnosis

Slit Lamp Examination

• Cells in the anterior chamber - graded 0 to 4+ by the Standardization of Uveitis Nomenclature (SUN) working group
• Flare - protein in the aqueous, giving a hazy beam; graded 0 to 4+
• Keratic precipitates - patterns guide diagnosis (see KP page)
• Posterior synechiae - adhesions of iris to lens
• Hypopyon - layer of inflammatory cells in severe cases

Other Examination

• Visual acuity
• Intraocular pressure - can be low (ciliary body inflammation reducing aqueous production) or elevated (trabeculitis, inflammatory cells obstructing outflow, posterior synechiae causing iris bombé, or steroid response). Herpetic, CMV, and Posner-Schlossman uveitis are classically associated with elevated IOP
• Pupil examination - irregular pupil with synechiae
• Dilated fundoscopic exam - to exclude posterior involvement

Workup at First Presentation

A first episode of acute anterior uveitis with no red flags can sometimes be managed empirically. A workup is appropriate for:

• Recurrent disease
• Bilateral disease
• Granulomatous features
• Atypical features
• Systemic symptoms

Typical tests:

• HLA-B27 typing
• Blood tests: CBC, ESR, CRP
• Syphilis serology (RPR/VDRL + treponemal-specific), often included because syphilis can mimic many uveitis patterns
• Tuberculosis testing (interferon-gamma release assay)
• ACE level + chest imaging if sarcoidosis suspected
• Lyme serology in endemic areas

Treatment

Topical Corticosteroids

• Prednisolone acetate 1% is a common first agent
• Often started frequently during waking hours and tapered as inflammation responds
• Duration varies; many acute episodes require several weeks of tapering
• Patients with frequent recurrences may need longer courses
• Difluprednate is a more potent alternative; loteprednol may be used in selected milder or steroid-response situations but is not a substitute for close monitoring

Cycloplegic Drops

• Your ophthalmologist will choose and prescribe a cycloplegic agent based on the severity of inflammation. Typical regimens include cyclopentolate 1% during active inflammation, homatropine 5%, or atropine 1% for severe inflammation; the dosing and frequency are individualized
• Relieve ciliary spasm and reduce pain
• Prevent posterior synechiae by keeping the pupil mid-dilated
• Frequency is adjusted to break or prevent synechiae as the inflammation responds

Treatment of Specific Causes

• Herpetic uveitis: oral antiviral (valacyclovir or acyclovir) plus topical steroid under supervision
• CMV anterior uveitis: antiviral therapy such as valganciclovir or topical/intravitreal options, depending on severity and specialist judgment
• Toxoplasma: oral antimicrobial therapy
• Syphilis: systemic penicillin regimen coordinated with infectious disease or primary care
• Sarcoidosis: topical, periocular, or systemic steroid depending on severity, with possible immunosuppressant therapy

Chronic / Steroid-Sparing Therapy

For frequent recurrences or steroid-dependent disease:

• Methotrexate
• Azathioprine
• Mycophenolate
• Biologic therapy such as TNF inhibitors in selected chronic non-infectious or systemic inflammatory disease, usually with uveitis/rheumatology input

Complications

• Posterior synechiae with secondary glaucoma if pupil cannot dilate
• Steroid-induced cataract and glaucoma with prolonged topical steroid use
• Cystoid macular edema - vision loss from chronic inflammation; detected on OCT
• Band keratopathy in chronic disease
• Hypotony in severe ciliary body involvement

Prognosis

Most acute anterior uveitis episodes resolve fully with prompt treatment. Recurrence is common, particularly in HLA-B27-associated cases. Chronic anterior uveitis (e.g., JIA-associated) requires long-term monitoring and immunosuppression. Sight-threatening complications are uncommon when treatment is timely.

Frequently Asked Questions

Is anterior uveitis the same as iritis?

Iritis describes inflammation of the iris specifically; iridocyclitis adds the ciliary body. "Anterior uveitis" is the encompassing term that includes both, and is the preferred clinical terminology.

Will it come back?

Approximately 50% of patients with HLA-B27-associated anterior uveitis have recurrent episodes. Other forms have variable recurrence rates. Patients with one episode are followed at intervals to look for new flares early.

Why do I need a workup if my first episode resolved with drops?

A first typical episode of unilateral acute non-granulomatous anterior uveitis often does not require systemic workup if it resolves quickly. Recurrent, bilateral, granulomatous, or atypical cases are different - the underlying cause matters for both ocular treatment and systemic management.

Can I drive with anterior uveitis?

Do not drive while vision is blurred, light sensitivity is severe, or cycloplegic drops have made the pupil too dilated to see comfortably. Once symptoms and vision are stable enough, driving can be discussed with the treating clinician.

Can my child have anterior uveitis?

Yes - juvenile idiopathic arthritis (JIA)-associated uveitis is often asymptomatic and detected on routine slit lamp screening. Children with JIA need scheduled slit-lamp screening - typically every 3 months in highest-risk groups for the first 4 years after diagnosis - even if their eyes feel fine.

References