Sandwiched between the retina and the sclera is a tissue abundant in blood vessels, called the choroid. When this choroidal layer becomes inflamed, we call the condition uveitis. There are many varieties of uveitis. Some types affect only the front or back part of the eye, while other types affect the entire eye.
There are many causes of uveitis. In fact, certain bacterial, viral, and fungal infections can lead to uveitis. Uveitis may arise from or be related to auto-immune diseases. These autoimmune diseases are conditions in which the body actually attacks its own tissue. A thorough physical examination, including specific laboratory tests, may discover the underlying cause. However, most of the time we are unable to actually determine the cause of uveitis. Nonetheless, even if no underlying cause can be determined, most of these cases still respond nicely to medication.
Fortunately, most patients with uveitis become aware of symptoms. For some, the eye becomes red, painful, and sensitive to light. For others, vision simply becomes blurred. Many cases of uveitis involve both eyes. Fortunately, a thorough eye examination can allow the eye doctor to detect uveitis. In fact, the careful observer can even detect cases of uveitis that occurred in the distant past.
Uveitis can go in a variety of directions. Many cases resolve after treatment and never occur again. Other patients have recurrent episodes in one eye and then the other. Unfortunately, there is a group of patients in which the uveitis continues to smolder for many years and never completely resolves, which is called chronic uveitis.
Careful follow-up examinations to assess the response to treatment is obligatory. Uveitis can result in glaucoma, cataracts, or retinal damage. Specifically, if the inflammation results in swelling of the macula and retina, central vision can be significantly compromised.
For most patients, treatment can slow down or prevent the development of many of these associated conditions; but, for a small group of patients, these conditions cannot be prevented. Sometimes surgery, either cataract extraction or vitrectomy — removal of the jelly of the eye — can be used to restore vision or aid in diagnosis.