Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid. Uveitis is described anatomically, by the part of the eye affected, as anterior, intermediate, or posterior, or panuveitic if all parts are involved. Anterior uveitis (iridocyclitis) is the most common, with the incidence of uveitis overall affecting approximately 1:4500, most commonly those between the ages of 20 and 60. Symptoms include eye pain, eye redness, floaters, and blurred vision, and ophthalmic examination may show dilated ciliary blood vessels and the presence of cells in the anterior chamber. Uveitis may arise spontaneously, have a genetic component, or be associated with an autoimmune disease or infection. While the eye is a relatively protected environment, its immune mechanisms may be activated, resulting in inflammation and tissue destruction associated with T-cell activation. Uveitis is an ophthalmic emergency that requires urgent control of the inflammation to prevent vision loss. Treatment typically involves the use of topical eye drops (steroids), intravitreal injection, newer biologics, and treating any underlying disease. While initial treatment is usually successful, complications include other ocular disorders, such as uveitic glaucoma, retinal detachment, optic nerve damage, cataracts, and in some cases, a permanent loss of vision. In the United States, uveitis accounts for about 10–20% of cases of blindness.
Classification Uveitis is classified anatomically into anterior, intermediate, posterior, and panuveitis forms—based on the part of the eye primarily affected. Before the twentieth century, uveitis was typically referred to in English as "ophthalmia."
Anterior uveitis includes iridocyclitis and iritis. Iritis is the inflammation of the anterior chamber and iris. Iridocyclitis is inflammation of the iris and ciliary body, with inflammation predominantly confined to the ciliary body. Between 66% and 90% of uveitis cases are anterior in location (iritis). This condition can occur as a single episode and subside with proper treatment or may take on a recurrent or chronic nature. Intermediate uveitis, also known as pars planitis, consists of vitritis—which is inflammation of cells in the vitreous cavity, sometimes with snowbanking, or deposition of inflammatory material on the pars plana. There are also "snowballs," which are inflammatory cells in the vitreous. Posterior uveitis or chorioretinitis is the inflammation of the retina and choroid. Panuveitis is the inflammation of all layers of the uvea.
Signs and symptoms
The disease course, anatomy, and laterality can vary widely and are important to consider in diagnosis and treatment. Cases may be acute (sudden onset with < 3-month duration) and monophonic, acute and recurrent, or chronic. The signs and symptoms of uveitis may include the following:
Anterior uveitis (iritis) Pain in the eye(s) Redness of the eye(s) Blurred vision Photophobia Irregular pupil Signs of anterior uveitis include dilated ciliary vessels, presence of cells and flare in the anterior chamber, and keratic precipitates ("KP") on the posterior surface of the cornea. In severe inflammation, there may be evidence of a hypopyon. Pigment deposits identify old episodes of uveitis on the lens, KPs, and a festooned pupil on dilation of the pupil. Busacca nodules, inflammatory nodules located on the surface of the iris in granulomatous forms of anterior uveitis such as Fuchs heterochromic iridocyclitis (FHI). Synechia, adhesion of the iris to the cornea (anterior synechiae) or more commonly the lens (posterior synechiae)
Intermediate uveitis
Most common:
Floaters, which are dark spots that float in the visual field Blurred vision Intermediate uveitis usually affects one eye. Less common is the presence of pain and photophobia.
Posterior uveitis Inflammation in the back of the eye is commonly characterized by:
Floaters Blurred vision
Causes Uveitis is usually an isolated illness, but it can be associated with many other medical conditions. In anterior uveitis, no associated condition or syndrome is found in approximately one-half of cases. However, anterior uveitis is often one of the syndromes associated with HLA-B27. Presence of this type of HLA allele has a relative risk of evolving this disease by approximately 15%. The most common form of uveitis is acute anterior uveitis (AAU). It is most commonly associated with HLA-B27, which has important features: HLA-B27 AAU can be associated with ocular inflammation alone or in association with systemic disease. HLA-B27 AAU has characteristic clinical features, including male preponderance, unilateral alternating acute onset, a non-granulomatous appearance, and frequent recurrences, whereas HLA-B27-negative AAU has an equivalent male-to-female onset, bilateral chronic course, and more frequent granulomatous appearance. Rheumatoid arthritis is not uncommon in Asian countries, with a significant association with uveitis.
Noninfectious or autoimmune causes
Sympathetic ophthalmia Behçet disease Crohn's disease Fuchs heterochromic iridocyclitis Granulomatosis with polyangiitis HLA-B27 related uveitis Spondyloarthritis (especially seen in ankylosing spondylitis) Juvenile idiopathic arthritis Sarcoidosis Tubulointerstitial nephritis and uveitis syndrome
Associated with systemic diseases Systemic disorders that can be associated with uveitis include:
Enthesitis Ankylosing spondylitis Juvenile rheumatoid arthritis psoriatic arthritis reactive arthritis Behçet's disease inflammatory bowel disease Whipple's disease systemic lupus erythematosus polyarteritis nodosa Kawasaki's disease chronic granulomatous disease sarcoidosis multiple sclerosis Vogt–Koyanagi–Harada disease
Infectious causes Uveitis may be an immune response to fight an infection caused by an organism in the eye. They are less common than non-infectious causes and require antimicrobial/viral/parasitic treatment in addition to inflammatory control. Infectious causes in order of global burden include: }
bartonellosis tuberculosis brucellosis human herpesvirus viruses (herpes simplex virus, herpes zoster ophthalmicus - shingles of the eye) leptospirosis presumed ocular histoplasmosis syndrome syphilis toxocariasis toxoplasmic chorioretinitis Lyme disease Zika fever
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