What is Uveitis?
Uveitis is an inflammation that occurs in the middle layer of the eye. It can also lead to inflammation in the adjacent areas, like the retina and fluid in the back of the eye (called vitreous).
Importance of Uveitis
When any part of the uvea becomes inflamed, the condition is labeled as uveitis. This may be further subdivided depending upon the exact structures involved in the inflammation. Thus, if only the iris is inflamed it is called Iritis. Similarly Cyclitis is inflammation of the ciliary body. Anterior uveitis or iridocyclitis is inflammation of both the iris and ciliary body. Choroiditis or posterior uveitis is inflammation of the choroid. Intermediate uveitis is inflammation of the middle part of the uvea and is commonly also referred to as pars planitis. If all structures (iris, ciliary body and choroid) are inflamed then it is called panuveitis. These are medical terms but are helpful for you to know.
The signs, symptoms and characteristics of uveitis may include:
- Eye redness
- Eye pain
- Light sensitivity
- Blurred vision
- Dark, floating spots in your field of vision (floaters)
- Decreased vision
Symptoms may occur suddenly and get worse quickly, though in some cases, they develop gradually. They may affect one or both eyes. Occasionally, there are no symptoms, and signs of uveitis are observed on a routine eye exam.
The uvea is the middle layer of tissue in the wall of the eye. It consists of the iris, the ciliary body and the choroid. When you look at your eye in the mirror, you will see the white part of the eye (sclera) and the colored part of the eye (iris).
The iris is located inside the front of the eye. The ciliary body is a structure behind the iris. The choroid is a layer of blood vessels between the retina and the sclera. The retina lines the inside of the back of the eye, like wallpaper. The inside of the back of the eye is filled with a gel-like liquid called vitreous.
The type of uveitis you have depends on which part or parts of the eye are inflamed:
- Anterior uveitis affects the inside of the front of your eye (between the cornea and the iris) and the ciliary body. It is also called iritis and is the most common type of uveitis.
- Intermediate uveitis affects the retina and blood vessels just behind the lens (pars plana) as well as the gel in the center of the eye (vitreous).
- Posterior uveitis affects a layer on the inside of the back of your eye, either the retina or the choroid.
- Panuveitis occurs when all layers of the uvea are inflamed, from the front to the back of your eye.