Uveitis
The term uveitis comes from uvea (vascular tunic) and refers to the iris, ciliary body and vascular tunic. Uveitis is the inflammation of these structures and generally occurs in both eyes. In iritis, the ciliary body is almost always inflammated; this is defined as iridocylitis. Inflammation of the vascular tissue is defined as chorioiditis. If the retina is also inflammated, this is defined as retinochoioiditis (inflammation of the retina and vessels).
In no other eye disease probable causes are so variable as in uveitis : Many microorganisms (bacteriae, viruses, fungi etc.) may directly invade the eye in eye injuries or reach the eye through the blood circulation in inflammation of other body parts and lead to uveitis. In pregnant women with infection, the bacteriae that are delivered by blood circulation may be dangerous for the child and lead to congenital uveitis. Uveitis may also occur in many rheumatic diseases (especially in joint inflammation). Nevertheless, the cause of uveitis can usually not be found despite detailed investigations. Autoimmune disease is mentioned in such cases. Here, the immune system suddenly perceives its own tissue as a foreign body and gives defense reaction to the uvea. The reaction of the immun system is manifested as inflammation. The uvea may be affected with different degrees. Single-centered or multi-centered inflammations (with a distance to each other) may be present. Sometimes, the whole uvea may be inflammated diffusely. Inflammatory cells invade the corpus vitreum and lead to cloudiness with different degrees especially in vasculitis. Uveitis may be an acute event that occurs once, but it usually recurs or becomes chronic from the beginning. In this case, the risks of permanent retina damage, lens cloudiness and increased intraocular pressure are especially high.
The symptoms depend on the parts of the uvea which are involved. In acute iridocyclitis, pain occurs in the depths of the eye, this expands to the periphery and increases in bright light. Inflammatory cells that accumulate excessively in the aqueous humor lead to blurred vision. A red eye and narrow pupil are also noticed. Generally, patients do not have many complaints in chronic iridocyclitis. Decreased visual acuity is mostly related with complications (for example, cataract). If the vascular tissue and retina are inflammated acutely (see picture), the symptoms depend on the location of the center and degree of inflammation. If the outer vascular layer is inflammated and the corpus vitreum is not very clouded, no to few complaints are observed. If the posterior part of the eye is inflammated, the visual acuity decreases markedly. In the chronic process, the visual acuity decreases markedly with complications including lens cloudiness, increased pressure and macular edema. Healed inflammation leaves a wound scar in the central retina, and this causes to narrowing of the visual field to a certain extent. The ophtalmologist examines intraocular inflammation using a biomicroscope, opthalmoscope and contact lens. Sometimes, dye test may also be required (Fluorescein angiography). In this method, especially the retinal changes in the macula can be picturized. A detailed blood test is always performed in cases of uveitis. Intraocular inflammation is treated by anti-inflammatory antibiotic eye drops or pills, corticosteroids and sometimes drugs which supress autoimmune reaction according to the cause. Sometimes cold therapy (cryotherapy) may be needed in inflammation of the vascular tissue and retina or in strong changes in the corpus vitreum. In advanced cases, operation of corpus vitreum (vitrectomy) may be required.