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Uveitis is inflammation of the uveal tract—the iris, ciliary body, and choroid. Most cases are idiopathic, but identifiable causes include various infections and systemic diseases, many of which are autoimmune. Symptoms include decreased vision, ocular ache, redness, photophobia, and floaters. Although intraocular inflammation is identified clinically, identifying the cause of the inflammation typically requires testing. Treatment depends on cause but typically includes topical, locally injected, or systemic corticosteroids with a topical cycloplegic-mydriatic drug. Noncorticosteroid immunosuppressive drugs may be used in severe and refractory cases. Infectious causes require antimicrobial therapy.
Inflammation of the uvea (uveitis) may occur with or without vitreitis, retinitis, papillitis, or optic neuritis. Uveitis is classified anatomically as anterior, intermediate, or posterior uveitis or panuveitis.
Anterior uveitis is localized primarily to the anterior segment of the eye and includes iritis (inflammation in the anterior chamber alone) and iridocyclitis (inflammation in the anterior chamber and anterior vitreous).
Intermediate uveitis (peripheral uveitis or chronic cyclitis) occurs in the vitreous.
Posterior uveitis refers to any form of retinitis, choroiditis, or inflammation of the optic disk.
Panuveitis (also called diffuse uveitis) implies inflammation in both the anterior and posterior chambers.
Etiology
Most cases are idiopathic and presumed to be autoimmune in origin. Identifiable causes include
The most common cause of anterior uveitis is trauma (traumatic iridocyclitis). Other causes are spondyloarthropathies (20 to 25%), juvenile idiopathic arthritis, and herpesvirus (herpes simplex and varicella-zoster) infection. Half of all cases of anterior uveitis are idiopathic.
Most intermediate uveitis is idiopathic. Uncommon identifiable causes include multiple sclerosis, sarcoidosis, TB, syphilis, and, in endemic regions, Lyme disease.
Most posterior uveitis (retinitis) is idiopathic. The most commonly recognized cause of posterior uveitis in immunocompetent patients is toxoplasmosis; the most commonly recognized cause in patients with HIV/AIDS is cytomegalovirus (CMV).
The most commonly identified cause of panuveitis is sarcoidosis, but most cases remain idiopathic despite appropriate testing.
Infrequently, systemic drugs cause uveitis (usually anterior). Examples are sulfonamides, pamidronate (an inhibitor of bone resorption), rifabutin, and cidofovir.
Systemic diseases causing uveitis and their treatment are discussed elsewhere in The Manual.
Symptoms and Signs
Symptoms and signs may be subtle and vary depending on the site and severity of inflammation.
Anterior uveitis tends to be the most symptomatic, usually manifesting with pain (ocular ache), redness, photophobia, and, to a variable degree, decreased vision. Signs include hyperemia of the conjunctiva adjacent to the cornea (ciliary flush or limbal injection). Slit-lamp findings include keratic precipitates (WBC clumps on the inner corneal surface), cells and flare (a haze) in the anterior chamber (aqueous humor), and posterior synechiae. With severe anterior uveitis, WBCs may layer in the anterior chamber (hypopyon).
Intermediate uveitis is typically painless and manifests with floaters and decreased vision. The primary sign is cells in the vitreous humor. Aggregates and condensations of inflammatory cells often occur over the pars plana (near the junction of the iris and sclera), forming "snowballs." Vision may be decreased because of floaters or cystoid macular edema, which results from fluid leakage from blood vessels in the macula. Confluent and condensed vitreous cells and snowballs over the pars plana may cause a classic "snowbank" appearance, which can be associated with neovascularization of the retinal periphery.
Posterior uveitis may give rise to diverse symptoms but most commonly causes floaters and decreased vision as occurs in intermediate uveitis. Signs include cells in the vitreous humor; white or yellow-white lesions in the retina (retinitis), underlying choroid (choroiditis), or both; exudative retinal detachments; retinal vasculitis; and optic disk edema.
Panuveitis may cause any combination of the previously mentioned symptoms and signs.
Complications
Serious complications of uveitis include profound and irreversible vision loss, especially when uveitis is unrecognized, inadequately treated, or both. The most frequent complications include cataract; glaucoma; retinal detachment; neovascularization of the retina, optic nerve, or iris; and cystoid macular edema (the most common cause of decreased vision in patients with uveitis).
Diagnosis
Uveitis should be suspected in any patient who has ocular ache, redness, photophobia, floaters, or decreased vision. Patients with anterior uveitis have ocular ache in the affected eye if light is shined in the unaffected eye (true photophobia), which is uncommon in conjunctivitis. Diagnosis of anterior uveitis is by recognizing cells and flare in the anterior chamber. Cells and flare are seen with a slit lamp and are most evident when using a narrow, intensely bright light focused on the anterior chamber in a dark room. Findings of intermediate and posterior uveitis are most easily seen after dilating the pupil (see Approach to the Ophthalmologic Patient: Ophthalmoscopy). Indirect ophthalmoscopy (usually done by an ophthalmologist) is more sensitive than direct ophthalmoscopy. (Note: If uveitis is suspected, patients should be referred immediately for complete ophthalmologic evaluation.)
Many conditions that cause intraocular inflammation can mimic uveitis and should be considered in the appropriate clinical settings. Such conditions include, most commonly, severe conjunctivitis (eg, epidemic keratoconjunctivitis), severe keratitis (eg, herpetic keratoconjunctivitis, peripheral ulcerative keratitis), and severe scleritis, and, less commonly, intraocular cancers in the very young (typically retinoblastoma and leukemia) and in the elderly (intraocular lymphoma). Much less commonly, retinitis pigmentosa (see Retinal Disorders: Retinitis Pigmentosa) can manifest with mild inflammation, which may be confused with uveitis.
Treatment
Treatment of active inflammation usually involves corticosteroids given topically (eg, prednisolone acetate 1% 1 drop q 1 h while awake) or by periocular or intraocular injection along with a cycloplegic-mydriatic drug (eg, homatropine 2% or 5% drops bid to qid depending on severity). Antimicrobial drugs are used to treat infectious uveitis. Particularly severe or chronic cases may require systemic corticosteroids (eg, prednisone 1 to 2 mg/kg po once/day), systemic noncorticosteroid immunosuppressive drugs (eg, methotrexate 15 to 20 mg po once/wk), laser phototherapy, cryotherapy applied transsclerally to the retinal periphery, or surgical removal of the vitreous (vitrectomy).
Key Points
Last full review/revision September 2012 by Emmett T. Cunningham, Jr., MD, PhD, MPH
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