Eye Concerns

Uveitis is one of the leading causes of blindness in the United States.  It is an inflammation of the inside the eye, specifically affecting one or more of the three parts of the eye that make up the uvea: the iris, the ciliary body and the choroid.

The eye and different types of Uveitis

The eye is a hollow, fluid-filled, ball-shaped organ. It has several layers. The outer layer is the tough coat composed of the cornea and sclera, the innermost is the retina, a thin light-receptor layer, and the middle layer is the uvea. The uvea is made up of iris, the ciliary body and the choroid. When any part of the uvea becomes inflammed then it is called uveitis.

Anterior Uveitis
This is the most common form of uveitis, accounting for 40 - 70% of cases. It is often referred to as Iritis as the iris is the part of the uvea that is usually inflammed.

Intermediate Uveitis
This affects the area just behind the ciliary body (pars plana) and also the most forward edge of the retina. This is the least common type (7 -15%) of uveitis.

Posterior Uveitis
This is when the inflammation affects the part of the uvea at the back of the eye, the choroid. Often the retina is affected in this group. The choroid is basically a layer rich in small blood vessels, which nourishes the photoreceptor layer of the retina. This kind of uveitis (15 - 22%) is commonly slower in onset and may last longer, and it is often more difficult to treat and is often associated with progressive loss of vision.

What are the symptoms?

The symptoms of uveitis can include:

•  Light sensitivity
•  Blurring of vision
•  Pain
•  Redness of the eye
•  Floaters

Uveitis may come on suddenly with redness and pain, or it may be slow in onset with little pain or redness, but gradual blurring of vision.
    

What are the causes?

Uveitis may be infectious -- resulting from virus, fungus, parasites or bacteria. It can also be non-infectious -- resulting from a trauma, an immunological process, or in many cases having no known etiology.

How can it be treated?

Currently the following are used to treat uveitis:

• Eye drops, especially steroids, to reduce inflammation and pain. Eye drops do not penetrate well to the back of the eye, therefore this type of treatment is not efficacious in posterior uveitis.
• Periocular injections of steroids. This is an uncomfortable form of therapy but can be very effective especially in acute episodes of uveitis. This effect is not long lasting (3-4 weeks).
• Systemic or oral administration of steroids, other immuno-suppressants or anti-metabolite drugs. These drugs have poor penetration into the eye and thus the systemic dose required to treat uveitis in the eye is frequently associated with side-effects in the rest of the body (including Cushing's Syndrome, renal, liver and bone-marrow damage).
  

The primary source for the information provided here is The Uveitis Information Group's Web site, www.uveitis.net .