Uveitis and infectious retinitis
Unlike other organs in our bodies, the eye tends to be spared the potential for our immune system to attack perceived foreign objects in the way the immune system can attack foreign objects in other parts of the body. The fascinating presence of this “immune privilege” is the subject of much scientific research into the understanding of our immune system in general.
However, for reasons that are not always clear, some patients lose the “immune privilege” of their eye and experience attack by their immune system against structures within the eye. This inflammatory attack against oneself is directed at such sensitive structures within the eye that pain and loss of vision may occur. In severe cases if the inflammation is not halted blindness may occur.
Uveitis is not a single disease, but rather can be triggered by a host of infections, autoimmune and malignant disorders. Prompt diagnosis and prompt treatment is critical in this challenging group of disorders.
Uveitis specifically refers to inflammation of the middle layer of the eye, termed the “uvea” but in common usage may refer to any inflammatory process involving the interior of the eye. Uveitis is estimated to be responsible for approximately 10% of blindness that exists in the United States. If uveitis is suspected or diagnosed, it requires a thorough examination by an ophthalmologist.
Uveitis is usually categorized anatomically into anterior, intermediate, posterior, and panuveitic forms. Anywhere from two-thirds to 90% of uveitis cases are anterior in location (anterior uveitis). This type is frequently referred to as iritis, meaning inflammation of the iris and anterior chamber. This condition can occur as a single episode and subside with proper treatment or may take on a recurrent or chronic nature. Symptoms include red eye, injected conjunctiva, pain, and decreased vision. Signs include dilated ciliary vessels, the presence of cells and flare in the anterior chamber, and keratic precipitates (KP) on the posterior surface of the cornea.
Intermediate uveitis consists of vitritis—that is, inflammatory cells in the vitreous cavity, sometimes with snowbanking—or deposition of inflammatory material on the pars plana.
Posterior uveitis is the inflammation of the retina and choroid. Pan-uveitis is the inflammation of all the layers of the uvea.
Depending on which part of the eye is inflamed in uveitis, various combinations of these symptoms may be present: redness, light sensitivity, floaters, blurry vision, and pain. These symptoms may come on suddenly, and the patient may not experience any pain.
The experience of these symptoms does not necessarily mean that a patient has uveitis. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.
Treatment may include steroid eye drops, injections, or pills, plus eye drops that dilate the pupil and reduce pain. More severe cases of uveitis may even require treatment with chemotherapeutic agents to suppress the immune system.