The uvea refers to the pigmented part of the three concentric layers of the eye. The constituents of the uvea include the iris, ciliary body, and choroid. The uveal tract can be divided into anterior (iris and ciliary body) and posterior (choroid) components. The term “uvea” may be a reference to the almost black color and wrinkled appearance when the uvea is stripped from the eye of a cadaver. The uveal tract is responsible for nutrition and gas exchange as well as light absorption. Some added functions include control of the focus of the eye, secretion of aqueous humour, and retinal illumination optimization.
When the uvea is inflamed, it results in a condition known as uveitis. Uveitis is considered an ophthalmic emergency where an examination and treatment by an ophthalmologist is required to help reduce the inflammation. It is an emergency as it can be serious and result in permanent loss of vision. To prevent the complications of uveitis, early diagnosis and treatment is key. This condition can affect one or both eyes and can be caused by infection (Lyme disease, herpes zoster, cat-scratch disease, toxoplasmosis, syphilis, West Nile virus), autoimmune disease (ankylosing spondylitis, sarcoidosis), injury, inflammatory disorder (ulcerative colitis, Crohn’s disease), or eye surgery. In many cases, the cause is unidentified (idiopathic uveitis). Studies have also shown significant association between cigarette smoking and uveitis. Left untreated, uveitis may result in complications such as permanent loss of vision, cataracts, glaucoma, retinal detachment, and optic nerve damage.
While it affects all ages, it usually affects those between the ages of 20 to 50 years old. It is estimated that there are 200 out of every 10,000 individuals newly diagnosed with uveitis annually. In the United States, uveitis causes about 10 to 15 percent of blindness with 30,000 new cases of legal blindness yearly. In pediatric patients, uveitis affects males more than females while in adults, females are affected more than males.
Symptom #1: Floaters
Floaters are deposits in the eye, specifically in the vitreous humor, that have various shapes, sizes, refractive index, and consistency. In most cases, the floaters occur due to the degenerative changes as the age of the individual progresses.
Floaters are only visible due to the shadows they cast on the retina. They can appear as fragments, cobwebs, threads, and spots. These imperfections float slowly and usually move in the direction where the eyes move. Floaters are more common in patients with intermediate and posterior uveitis.