Uveitis refers to a group of inflammatory conditions that occur in the eye. Often uveitis reflects diseases that are developing elsewhere in the body. Sometimes uveitis is the first evidence of disease in the body. In most cases, the cause of uveitis is unknown.
Inflammation vs. Infection
The symptoms of inflammation are swelling, redness, and dilated blood vessels. Infection occurs when a germ is growing in tissue. Not all inflammation indicates an infection. Inflamed joints in arthritis are seldom infected. Scraped skin is inflamed but not infected. Infection (germs-bacteria and viruses) can also cause inflammation. In uveitis, inflammation can be due to an infection or due to non-infective causes.
The symptoms of acute uveitis are frequent pain, red eyes, and light sensitivity (photophobia). In chronic uveitis, patients complain of dull aches and/or blurring of vision.
Since many kinds of uveitis have no known cause, they are treated nonspecifically with corticosteroids (cortisone) to suppress inflammation and to prevent structural damage to the eye. Corticosteroids may be addressed in the form of eyedrops, ointments, injections next to the eye, or pills. Corticosteroids in the pill form (prednisone) can have serious side effects. As a result, Ophthalmologists treat most cases of uveitis with eyedrops or injections of corticosteroids next to the eye. Even “local” corticosteroids have side effects, including cataracts, glaucoma, and the loss of ability to fight infections around the eye caused by bacteria, fungi, or viruses. Any patient on corticosteroids must be carefully monitored for side effects by an Ophthalmologist.
Common Types of Uveitis
Acute iritis (inflammation of the iris) affects young adults. It begins abruptly with symptoms of pain, redness, and photophobia (light sensitivity). Often, patients have a genetic tendency to acute iritis, and other family members may have had iritis. This genetic tendency often predisposes patients to other diseases such as ankylosing spondylitis (arthritis of the lower back), inflammatory bowel disease (colitis), and psoriasis (scaling skin disease).
By and large, attacks of uveitis last for two to six weeks and usually occur only in one eye. Some patients have only one or two attacks in a lifetime, and others have multiple episodes. Acute iritis is usually treated with eyedrops but occasionally pills or injections are necessary.
Chronic iridocyclitis affects the iris and ciliary body (glandlike structure) behind the iris. Chronic iridocyclitis often displays few symptoms but can severely damage the eye. This is especially true in children who have juvenile rheumatoid arthritis. In these children, especially in girls aged 2 to 6 years, this is a potentially blinding condition. Many of these children do not complain about problems with their sight. Therefore, it is important for pediatricians to refer all children with juvenile rheumatoid arthritis to an Ophthalmologist for evaluation. Since chronic iridocyclitis may start years after the juvenile rheumatoid arthritis began, children with this form of arthritis should have periodic checkups into their teenage years.
Pars planitis tends to occur in teenagers and young adults. The cause is unknown, and pars planitis is not associated with any systemic disease (disease of the whole body). The frequent symptoms are those of blurred vision or floaters (spots before the eyes). Most patients with pars planitis have a promising outcome after treatment. However, a few patients have severe visual problems.
Toxoplasmic retinitis is an infection of the retina caused by a protozoan parasite. Over 30% of the American population is exposed to this parasite. If a pregnant woman is infected, her infant is at risk of eye disease and even mental retardation. Besides acquiring this parasite at birth, people can also be infected by eating raw or undercooked meat or by handling cat feces.
Infection of the retina by toxoplasmosis can be blinding. In most cases, antibiotics can control the infection and suppress the inflammation. However, the infection is rarely cured and can be reactivated. The Uveitis Clinic at the University of Illinois was the first to use “quadruple antibiotic therapy” to treat toxoplasmosis. Due to the success of this therapy, many other centers now use it to treat this difficult infection.
Sarcoidosis is an inflammation of unknown cause. It can affect any part of the body but is most commonly found in the lungs, skin, and eyes. In the eyes, it can cause iritis or chorioretinitis (disease of the retina and choroid). Usually the symptoms are decreased vision and mild discomfort around the eyes. Most cases of sarcoidosis of the eye are treated with corticosteroids.
A final type of uveitis is viral retinitis. Herpes viruses, (including CMV, cytomegalovirus), which are normally kept at bay by the patient’s immune defenses, can, at times, destroy the retina. People whose immunity has been weakened due to diseases such as cancer or AIDS (acquired immunodeficiency syndrome) or from chemotherapy are at greater risk than others for this type of infection. Until recently if the immunity of these patients could not be restored, there was little that could be done to prevent damage to their eyes. Fortunately, new antibiotics have been developed that seem to work well against these viruses.