What Is Uveitis?
Uveitis is swelling of the middle layer of the eye, which is called the uvea. The uvea supplies blood to the retina. The retina is the light-sensitive part of the eye that focuses the images you see and sends them to the brain. It is normally red due to its blood supply from the uvea.
The cause of uveitis is often not known and frequently occurs in otherwise healthy people. However, it can also be associated with another illness such as an autoimmune disorder or an infection from a virus or bacteria. Uveitis may cause blurred vision, floaters (dark floating spots in your field of vision), and eye pain.
Uveitis is often treated with eye drops. Normally, the condition isn’t serious. If uveitis is caused by another condition, treating that underlying condition may eliminate the uveitis. More severe cases of uveitis can cause vision loss if not treated early enough.
What Causes Uveitis?
In many cases, particularly in healthy individuals, the cause is unknown. Some types of uveitis may be caused by an underlying autoimmune or inflammatory disorder. An autoimmune disease occurs when your own immune system attacks a part of your body. These conditions include:
- rheumatoid arthritis
- ankylosing spondylitis
- Behcet’s syndrome
- ulcerative colitis
- Kawasaki disease
- Crohn’s disease
Infections are another cause of uveitis, including:
- AIDS (viral infection)
- herpes (viral infection)
- CMV retinitis (viral infection of the eye)
- syphilis (sexually transmitted bacterial infection)
- toxoplasmosis (parasitic infection)
- tuberculosis (bacterial infection)
- histoplasmosis (fungal infection)
- West Nile (viral infection)
Other potential causes of uveitis include exposure to a toxin that penetrates the eye or bruising, injury, or trauma to the eye
Types of Uveitis
There are many types of uveitis. Each type is classified by where the inflammation occurs in the eye. They include:
Anterior Uveitis (Front of the Eye)
Anterior uveitis is often referred to as “iritis” because it affects the iris. The iris is the colored part of the eye near the front. Iritis is the most common type of uveitis and generally occurs in healthy people. It can affect one eye, or it may affect both eyes at once. Iritis is usually the least serious type of uveitis.
Intermediate Uveitis (Middle of the Eye)
Intermediate uveitis involves the middle part of the eye and is also called iridocyclitis. The word intermediate in the name refers to the location of the inflammation and not the severity of the inflammation. The middle part of the eye includes the pars plana, the part of the eye between the iris and the choroid. This type of uveitis may occur in otherwise healthy people, but has been linked to some autoimmune diseases such as multiple sclerosis.
Posterior Uveitis (Back of the Eye)
Posterior uveitis may also be referred to as choroiditis because it affects the choroid. The tissue and blood vessels of the choroid are important because they deliver blood to the back of the eye. This type of uveitis usually occurs in people with an infection from a virus, parasite, or fungus, or who have an autoimmune disease. Posterior uveitis tends to be more serious than anterior uveitis because it can cause scarring in the retina. The retina is a layer of cells in the back of the eye. However, posterior uveitis is the least common form of uveitis.
Pan-Uveitis (All Parts of the Eye)
When the inflammation affects all major parts of the eye, it is called pan-uveitis. It often involves a combination of features and symptoms from all three types of uveitis.
What Are the Symptoms of Uveitis?
The following symptoms may occur in one or both eyes:
- redness in the eye
- eye pain
- floaters (dark floating spots in your vision)
- sensitivity to light
- blurred vision
How Is Uveitis Diagnosed?
An eye doctor (ophthalmologist) will conduct an eye examination and take a complete health history.
Certain laboratory tests may be ordered to rule out an infection or autoimmune disorder. The ophthalmologist may refer you to another specialist if an underlying condition is suspected to be the cause of your uveitis.
How Is Uveitis Treated?
Treatment for uveitis depends on the cause and the type of uveitis. The goal of treatment is to reduce the inflammation in the eye.
Treatment for anterior uveitis (iritis) includes:
- dark glasses
- eye drops to dilate the pupil and reduce pain
- steroid eye drops to reduce inflammation
Treatment for posterior uveitis may include:
- steroids taken by mouth
- visits to additional specialists to treat the infection or autoimmune disease. A body-wide infection will usually be treated with antibiotics.
Treatment for intermediate uveitis includes:
- steroid eye drops
- steroids taken by mouth
Severe cases of uveitis may require drugs that suppress the immune system.
Post-Treatment Recovery and Outlook
Uveitis will typically go away within a few days with treatment. Uveitis that affects the back of the eye (posterior uveitis) typically heals more slowly than uveitis that affects the front of the eye. Relapses are common.
Posterior uveitis due to another condition may persist for months and can cause permanent vision damage.
Potential Complications from Uveitis
Untreated uveitis can lead to serious complications, including:
- cataracts (clouding of the lens or cornea)
- fluid in the retina
- glaucoma (high pressure in the eye)
- retinal detachment
- loss of vision
How Can Uveitis Be Prevented?
Seeking proper treatment for an autoimmune disease or infection can help to prevent uveitis. However, uveitis in otherwise healthy individuals cannot usually be prevented since the cause is not yet known.
Early detection and treatment is important to reduce the risk of vision loss, since the vision loss can be permanent.