Uveitis means "inflammation of the uvea", or the middle layer of the eye. The uvea consists of three structures: the iris, the ciliary body, and the choroid. When any part of the uvea becomes inflamed then it is called Uveitis. A big problem, when trying to understand Uveitis, for patients and doctors alike, is that there are many different types of Uveitis. Uveitis is estimated to be responsible for approximately 12% of the blindness in the United States.

Causes

The causes of uveitis depends on there type. Anterior uveitis refers to inflammation of the iris alone or the iris and ciliary body; anterior uveitis is the most common form. Intermediate uveitis refers to inflammation of the ciliary body. Posterior uveitis is inflammation of the choroid. Diffuse uveitis is inflammation in all areas of the uvea. It may result from an infection such as a virus (e.g. herpes) or a fungus (e.g. histoplasmosis). It may be due to a parasite such as toxoplasmosis.

It may be related to Autoimmune Disease (with or without involvement of other parts of the body). This, essentially, is when our immune system recognises a part of our own body as foreign (albeit a small part, like one type of protein).
The inflammation causes spotty areas of scarring on the choroid and retina that result in areas of vision loss. The degree of vision loss depends on the amount and location of scarring. If the central part of the retina, called the macula, is involved, central vision becomes impaired.

Symptoms

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. Common symptoms of uveitis include :-

Eye redness
Eye pain
Light sensitivity
Blurred vision
Dark, floating spots in your field of vision
Decreased vision
Small pupil
Tearing
Elevated intraocular pressure

Treatment

The appropriate treatment for uveitis is dependent on the severity of the disease. Topical eye drops and/or oral medications are prescribed to reduce inflammation. In some cases, medication is required to lower the intraocular pressure.
Uveitis is typically treated with glucocorticoid steroids, either as topical eye drops (such as betamethasone, dexamethasone or prednisolone) or oral therapy with prednisolone tablets. In addition topical cycloplegics, such as atropine or homatropine, may be used.
Antimetabolite medications, such as methotrexate are often used for recalcitrant or more aggressive cases of uveitis. Experimental treatment with Infliximab infusions may prove helpful.