Medical term:

uveitis

Uveitis

Definition

Uveitis is an inflammation of the uveal tract, which lines the inside of the eye behind the cornea. Much of the uvea lies between the retina and tough, outer sclera. The uveal tract has three parts: the iris, the ciliary body, and the choroid. Uveitis is categorized according to the part of the uveal tract that is affected. Anterior uveitis is an inflammation of the front part of the uveal tract; it includes inflammation of the iris (iritis) and inflammation of the iris and the ciliary body (iridocyclitis). Posterior uveitis is an inflammation of the part of the uveal tract behind the lens of the eye. It includes inflammation of the choroid (choroiditis) and inflammation of the choroid and retina (chorioretinitis). Uveitis that affects the entire uveal tract is called panuveitis or diffuse uveitis.

Description

The uveal tract is made up of the iris, ciliary body, and choroid. The iris is the colored part of the eye. The ciliary body is inside the eye and produces a fluid called aqueous humor. Ciliary muscles aid in accommodation, the process of changing the shape of the lens in the eye to see things at various distances. The choroid lines the back of the eye and has many blood vessels. It helps nourish part of the retina. The choroid lies between the retina and outermost sclera.

Uveitis may either persist for a long time (chronic) or have a short-term duration (acute). Anterior uveitis is classified as either granulomatous or nongranulomatous. The distinction is based on the disease agents that were considered responsible for the condition. At one time, it was thought that granulomatous uveitis was caused by tuberculosis bacilli whereas nongranulomatous uveitis was thought to be caused by streptococci. The distinction is still used even though the causes of uveitis are now understood differently.

In most cases, uveitis affects only one eye, although posterior uveitis sometimes involves both eyes. About 60% of cases develop within the eye itself, but 40% are associated with systemic diseases or disorders ranging from toxoplasmosis to syphilis. Many of these are diseases of childhood and adolescence. Uveitis does not appear to run in families or to be associated with lifestyle choices, occupational history, geographical location, or environmental factors.

Uveitis is a serious condition that may develop rapidly and cause lasting damage to the eye. Patients who think they may have chronic uveitis should seek evaluation and treatment by an ophthalmologist (a physician who specializes in diseases of the eye) as soon as possible. If the patient has a sudden loss of vision and the eye looks inflamed, the patient should go immediately to the doctor for emergency treatment.

Causes and symptoms

The causes of uveitis are not fully understood, but they can be a result of trauma, allergy, or a response to a systemic or ocular disease. Uveitis may be a type of immune-response mechanism. In people with impaired immune systems, uveitis may be due to an infection.

Chronic uveitis is often associated with systemic disorders (e.g., Lyme disease, sarcoidosis, or juvenile rheumatoid arthritis).

Anterior uveitis

The so-called classic symptoms of anterior uveitis—severe pain; redness, particularly around the edge of the iris; and extreme sensitivity to light (photophobia)—occur mostly in acute uveitis. In anterior uveitis, the doctor will see a so-called "flare and cell" pattern when looking into the watery fluid (aqueous humor) between the cornea and the lens of the patient's eye. The iris may adhere to the lens, thus increasing the intraocular pressure. There may be nodules on the iris. There may be tearing and the pupil may be constricted and nonreactive. In severe cases of anterior uveitis, there may be hypopyon (a small amount of pus or collection of white cells) visible when the doctor examines the eye.

GRANULOMATOUS UVEITIS. In granulomatous uveitis, there will be large yellowish-white cells visible on the back of the cornea, and possibly some small nodules on the iris. Granulomatous uveitis is usually less acute than the nongranulomatous form; the eye is only mildly inflamed and the patient's vision is somewhat blurred.

Granulomatous uveitis can be produced by syphilis, toxoplasmosis, cytomegalovirus, sarcoidosis, tuberculosis, or Vogt-Koyonagi-Harada syndrome (VKH). VKH is marked by severe uveitis associated with hair loss, hearing loss, loss of pigment in the eyelashes and brows, and headaches. It occurs most commonly in Asians.

NONGRANULOMATOUS UVEITIS. In nongranulomatous uveitis, the cells visible on the cornea are smaller, and there are no masses on the iris. This type of anterior uveitis is, however, more painful. The eye is red and the patient experiences both photophobia and loss of vision.

Systemic diseases that can cause nongranulomatous uveitis include ankylosing spondylitis, Reiter's syndrome, psoriasis, ulcerative colitis, Behcet's syndrome, Lyme disease, and Crohn's disease. Children—especially girls—with anterior uveitis should be screened for juvenile rheumatoid arthritis (JRA).

Posterior uveitis

The symptoms of posterior uveitis are sometimes subtle. The patient may notice blurred or hazy vision, or floating black spots before the eyes. There may be pain and photophobia. The iris may attach to the lens in the eye thus increasing intraocular pressure.

Posterior uveitis may be acute or chronic. It is more likely to involve both eyes. When the doctor examines the eye, cells may be seen in the vitreous humor, which is the normally transparent gel that fills the eyeball behind the lens. There will be yellowish or dark areas of inflammation on the choroid and the retina. The blood vessels in the retina develop a sheath or covering of inflammatory tissue. In severe cases, the vitreous humor is so cloudy that the doctor cannot see the retina at the back of the eye.

PARS PLANITIS. Pars planitis is an inflammation of the pars plana, which is a part of the ciliary body. Pars planitis usually occurs in older children or young adults, and can develop into posterior uveitis.

The diseases that cause granulomatous uveitis may also cause posterior uveitis.

Diagnosis

The eye doctor will examine the patient's eyes with a slit lamp in order to rule out conjunctivitis and certain types of glaucoma. The slit lamp is an instrument that combines a binocular microscope with a special light. The slit lamp can shine a narrow beam of very bright light into the eye and allow the doctor to examine the front part of the eye in detail. The slit-lamp exam is not painful, however if the patient is sensitive to light there will be discomfort.

Key terms

Choroid — The part of the uveal tract behind the ciliary body. The choroid underlies and nourishes the retina and absorbs scattered light.

Ciliary body — The part of the uveal tract between the iris and the choroid.

Cornea — The transparent front part of the eye that covers the iris and pupil.

Flare and cell — A pattern revealed by slit-lamp examination that indicates uveitis. Flare and cell resembles light filtered through smoke.

Hypopyon — A small amount of pus or collection of white cells that is visible in the front of the eye in severe cases of anterior uveitis.

Iris — The circular membrane that forms the colored portion of the eye and expands or contracts around the pupil.

Photophobia — Extreme sensitivity to light. Photophobia is a major symptom of acute uveitis.

Pupil — The opening in the center of the iris that allows light to pass through to the retina.

Retina — The innermost membrane at the back of the eyeball on which images are projected by the lens.

Slit lamp — An instrument that combines a binocular microscope with special lights. It allows an eye doctor to examine the front portion of the eye.

Uveal tract — The pigmented membrane that lines the back of the retina of the eye and extends forward to include the iris. The uveal tract is sometimes called the uvea and has three parts: the iris, the choroid, and the ciliary body.

Vitreous humor — The clear gel-like substance that fills the eyeball behind the lens.

The absence of a discharge from the eye and the absence of infectious organisms in a laboratory smear usually rule out conjunctivitis. In addition, the size of the pupil is often small in uveitis whereas it is normal in conjunctivitis. In acute glaucoma, the patient has severe pain, the cornea of the eye is cloudy, and the pressure level of the fluid inside the eye is abnormally high; whereas in uveitis the pain is moderate, the cornea is clear, and the fluid pressure is normal or possibly lower or slightly above normal. The doctor may also use the slit lamp and another lens to examine the back of the eye to get a good look at the retina and choroid. Other instruments, such as a hand-held ophthalmoscope or a binocular indirect ophthalmoscope, can be used to examine the back of the eye. There should be no discomfort with these tests except if the patient is sensitive to the bright light.

Laboratory testing

Laboratory testing is used to rule out conjunctivitis in some patients. The doctor wipes the inside of the patient's eyelid with a swab in order to obtain a sample for testing. Although blood tests are not necessary to diagnose uveitis by itself, they are used to diagnose the cause if the doctor suspects that toxoplasmosis or another systemic disease is responsible for the uveitis.

Treatment

Uveitis is generally treated by an ophthalmologist because therapy requires topical and oral medications, however, some optometrists (O.D.) are state licensed to use therapeutic medications. Other doctors may be involved in treating the underlying disease, if the patient has one, and in monitoring the patient's responses to medications.

Anterior uveitis is treated with corticosteroid drops; in severe cases, the patient may be given steroid injections in the area of the eye or oral steroids. Atropine sulfate drops may be given to dilate the patient's pupil. Posterior uveitis is treated with systemic corticosteroids. It is usually not necessary to dilate the pupil.

Prolonged steroid use may increase intraocular pressure, thereby increasing the risk of glaucoma. Steroid use has also been connected to cataract formation. Patients should be monitored closely and frequently.

Prognosis

The prognosis depends upon the location of the uveitis, on whether it is chronic or acute, and on the promptness of treatment. The prognosis for untreated uveitis is poor. Untreated anterior uveitis usually progresses to posterior uveitis, resulting in cataracts, scar tissue, and eventual glaucoma. If treated promptly, anterior uveitis usually clears up in several days or weeks, but is likely to recur. Posterior uveitis usually results in some permanent loss or blurring of vision.

Prevention

Patients with anterior uveitis should be warned about the possibility of recurrence and instructed about its symptoms, especially inflammation of the iris. They should be advised to seek treatment at once at the first signs of recurrence.

Resources

Organizations

American Academy of Ophthalmology. 655 Beach Street, P.O. Box 7424, San Francisco, CA 94120-7424. http://www.eyenet.org.

American Optometric Association. 243 North Lindbergh Blvd., St. Louis, MO 63141. (314) 991-4100. http://www.aoanet.org.

uveitis

[u″ve-i´tis]

an inflammation of part or all of the middle (vascular) tunic of the eye, the uvea. The term also includes inflammation that involves the other tunics (the sclera and cornea, and the retina). adj., uveit´ic.

heterochromic uveitis heterochromic iridocyclitis.

sympathetic uveitis sympathetic ophthalmia.

u·ve·i·tis

, pl.

u·ve·i·ti·des

(yū'vē-ī'tis, -it'ĭ-dēz),

Inflammation of the uveal tract: iris, ciliary body, and choroid.

[uvea + G. -itis, inflammation]

uveitis

(yo͞o′vē-ī′tĭs)

Inflammation of the uvea.

uveitis

Choroidoretinitis Ophthalmology Inflammation of the uveal tract–iris, ciliary body, choroid, uvea–the vascular layer between sclera and retina Types Anterior uveitis–aka iritis, linked to autoimmune disease; posterior uveitis–granulomatous affects choroid and/or retina, and may follow systemic infection Etiology Allergy, infection–eg, Toxoplasma gondii–congenital uveitis, histoplasmosis, TB, CMV, trauma, chemicals, idiopathic, ulcerative colitis, pauciarticular rheumatoid arthritis, Kawasaki disease, HSV, ankylosing spondylitis, Behçet disease, sarcoidosis, psoriasis, Reiter syndrome, syphilis; posterior uveitis causes patchy scars that correspond to vision defects; if the macula is involved, central vision is impaired. See Granulomatous uveitis, Salt & pepper choroidoretinitis.

u·ve·i·tis

, pl. uveitides (yū'vē-ī'tis, -it'i-dēz)

Inflammation of the uveal tract: iris, ciliary body, and choroid.

[uvea + G. -itis, inflammation]

uveitis

Inflammation of the UVEA. Uveitis of the front part of the uvea is called IRIDOCYCLITIS or anterior uveitis, inflammation of the rear part is called CHOROIDITIS or posterior uveitis.

uveitis

Inflammation of the uvea. All three tissues of the uvea tend to be involved to some extent in the same inflammatory process because of their common blood supply. However, the most severe reaction may affect one tissue more than the others as in iritis, cyclitis or choroiditis or sometimes two tissues, e.g. iridocyclitis. The symptoms also vary depending upon which part of the tract is affected. Acute anterior uveitis is accompanied by pain, photophobia and lacrimation and some loss of vision because of exudation of cells (aqueous flare), protein-rich fluid and fibrin into either the anterior chamber or vitreous body, as well as ciliary injection, adhesion between the iris and lens (posterior synechia), miosis and keratic precipitates. The condition is often associated with ankylosing spondylitis, rheumatoid arthritis, sarcoidosis, syphilis or tuberculosis (usually with granulomatous uveitis). It is the most common form of uveitis. Many cases are HLA-B27 positive. Treatment includes corticosteroids and mydriatics to reduce the risk of posterior synechia and to relieve a spasm of the ciliary muscle. See juvenile idiopathic arthritis; Reiter's disease; Busacca's nodules; Koeppe's nodules; sympathetic ophthalmia; Behçet's syndrome; phthisis bulbi; synchisis scintillans; Vogt-Koyanagi-Harada syndrome; Table I6.
fungal uveitis Uveitis caused by a fungus such as Candida albicans, Cryptococcus neoformans and Histoplasma capsulatum. It is often accompanied by other disorders (e.g. choroiditis, retinitis). It may have spread from other bodily tissues (e.g. skin, mouth, gastrointestinal tract) in patients who are intravenous drug addicts, patients with indwelling venous catheters or patients who are immunosuppressed.
intermediate uveitis A chronic inflammation of the ciliary body (cyclitis) or its pars plana zone (pars planitis) or of the peripheral retina and vitreous (peripheral uveitis). The cause is unknown in most cases but others are associated with systemic conditions such as multiple sclerosis, sarcoidosis or HIV infection. It affects mainly young adults and is bilateral in about 80% of cases. Symptoms are floaters and, sometimes, blurred vision, and there may be anterior chamber cells and flare. Ophthalmoscopic examination may show vitreous condensation and gelatinous exudates ('cotton balls' or 'snowballs'). Snowbanking, i.e. a whitish plaque or exudates involving the pars plana, often the inferior part of it, appears mainly in pars planitis. Intermediate uveitis may be associated with retinal vasculitis (i.e. inflammation of a retinal blood vessel). In a few cases the condition is self-limiting within a few months. However, in most cases the condition lasts several years may lead to complications such as cystoid macular oedema, posterior subcapsular cataract, retinal detachment or cyclitic membrane formation. Treatment includes corticosteroids and in resistant cases immunosuppressive agents.
posterior uveitis A uveitis involving the posterior segment of the eye. Symptoms include floaters and visual loss if the choroiditis involves the macular area. Ophthalmoscopically there is an accumulation of debris in the vitreous and choroidal lesions appear as yellow-white areas of infiltrates surrounded by normal fundus. Retinitis is also present in most cases, as well as retinal vasculitis. Posterior uveitis may be associated with AIDS, Behçet's disease, Lyme disease, histoplasmosis, sarcoidosis, toxoplasmosis, syphilis, tuberculosis, Vogt-Koyanagi-Harada syndrome, sympathetic ophthalmia, etc.
viral uveitis Uveitis caused by a virus. Common viruses are: herpes simplex, which is usually associated with keratitis and may cause anterior uveitis; herpes zoster which may also be associated with keratitis; human T-cell lymphotrophic virus; measles; cytomegalovirus; rubella; human immunodeficiency virus (HIV). See herpes simplex blepharoconjunctivitis; herpes zoster ophthalmicus.

u·ve·i·tis

, pl. uveitides (yū'vē-ī'tis, -it'i-dēz)

Inflammation of the uveal tract: iris, ciliary body, and choroid.

[uvea + G. -itis, inflammation]

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