What is uveitis?
Uveitis refers to inflammation of the middle layer of the eye (the uvea), but in common usage, it refers to all inflammatory processes inside the eye. The eye is shaped like a tennis ball, with three different layers surrounding a gel-filled cavity. The innermost layer is the retina, which is like the film in a camera. The middle layer, between the sclera and the retina, is called the uvea. The outermost layer is the sclera, the strong white wall of the eye. The uvea includes the iris (colored part of the eye), choroid (a thin membrane containing many blood vessels) and ciliary body (the part of the eye that joins these together). The uvea is very important because its many veins and arteries transport blood to the parts of the eye that are critical for vision.
What are the symptoms of uveitis?
Symptoms of uveitis may include eye redness, blurred vision, pain, or light sensitivity. Uveitis may develop rapidly. It is very important that you see your ophthalmologist for a complete eye examination if you develop these symptoms, especially if a painful, red eye does not clear up quickly. Left untreated, uveitis may permanently damage your vision.
What causes uveitis?
Uveitis has many potential causes, including viral, fungal, bacterial, or parasitic infections. It may be associated with systemic diseases or develop following an injury to the eye.
There are several types of uveitis categorized according to the location of inflammation:
- Iritis, the most common form of uveitis, affects the iris. This condition is often associated with autoimmune disorders such as arthritis. Iritis may develop suddenly and may last up to eight weeks, even with treatment.
- Cyclitis is inflammation of the middle portion of the eye and may affect the muscle that focuses the lens. This also may develop suddenly and last several months.
- Retinitis affects the back of the eye. It may be rapidly progressive, making it difficult to treat. Retinitis may be caused by viruses such as herpes zoster or herpes simplex, bacterial infections such as syphilis, or parasitic inflections such as toxoplasmosis or autoimmune diseases.
- Choroiditis, or inflammation of the layer beneath the retina, may also be caused by an infection such as tuberculosis or be due to autoimmune diseases.
- Panuveitis refers to inflammation involving the entire interior of the eye.
Uveitis also may be caused by injury to the eye. In a large number of cases, the cause of uveitis is not known.
How is uveitis diagnosed?
Uveitis can permanently damage your eyesight and even cause blindness. If you have any symptoms of uveitis, it is very important for you to see your ophthalmologist right away. Your ophthalmologist will perform a careful examination of your eyes. He or she may order laboratory tests including blood work or X-rays. Uveitis may have an underlying cause elsewhere in your body and your ophthalmologist may want to talk with your primary care physician or a specialist to evaluate your general medical condition.
How is uveitis treated?
Because uveitis is serious, treatment needs to begin right away. For noninfectious uveitis, your ophthalmologist may prescribe eye drops containing steroids to reduce swelling and a dilating drop to relieve pain. Antibiotics are used in patients with infectious uveitis. Dark glasses will help with light sensitivity. For severe cases, other medications may be prescribed.
Complications of uveitis may include glaucoma, cataract, abnormal blood vessel growth, fluid within the retina, and vision loss. Early diagnosis and treatment by your ophthalmologist can often help to avoid vision loss.