Uveitis Clinic

Definition of uveitis?

Uveitis is the inflammation of the uvea, a part of the eye.

Description of Uveitis

The eye is shaped much like a tennis ball, hollow inside with three different layers of tissue surrounding a central cavity. The outermost is the sclera (white coat of the eye) and the innermost is the retina (image-gathering tissue in the back of the eye much like the film in a camera).

The middle layer between the sclera and the retina is called the uvea, from the Greek word “uva” meaning grape. In the laboratory, it looks much like a “peeled grape.” When the uvea becomes inflamed, the condition is called uveitis.

The uvea contains many of the blood vessels which nourish the eye. Inflammation of the uvea can affect the cornea, the retina, the sclera, and other vital parts of the eye.

Since the uvea borders many important parts of the eye, inflammation of this layer may threaten sight more seriously than the more common inflammation of the outside layers of the eye.

When the uvea is inflamed near the front of the eye in the iris, it is called iritis. If the uvea is inflamed in the middle of the eye involving the ciliary body, it is called cyclitis. If the inflammation is in the back of the eye affecting the choroid, it is called choroiditis.

Anatomical Classification

Uveitis may be classified anatomically into anterior, intermediate, posterior and panuveitic forms, based on which part of the eye is primarily affected by the inflammation.

  • Anywhere from two-thirds to 90% of uveitis cases are anterior in location (anterior uveitis), frequently termed iritis – or 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, presence of cells and flare in the anterior chamber, and keratic precipitates (“KP”) on the posterior surface of the cornea.
  • Intermediate uveitis (pars planitis) consists of vitritis – 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.
Conditions associated with uveitis and uveitis syndromes

Myriad conditions can be associated with uveitis, including diseases with major extra-ocular involvement, as well as syndromes confined to the eye. 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%.

Systemic disorders associated with uveitis

Systemic disorders that can be associated with uveitis include:

  • Ankylosing spondylitis
  • Behçet’s disease
  • Chronic granulomatous disease
  • Enthesitis
  • Inflammatory bowel disease
  • Juvenile rheumatoid arthritis
  • Kawasaki’s disease
  • Multiple sclerosis
  • Polyarteritis nodosa
  • Psoriatic arthritis
  • Reactive arthritis
  • Sarcoidosis
  • Systemic lupus erythematosus
  • Vogt-Koyanagi-Harada syndrome
  • Whipple’s disease
  • Lyme disease
  • A wide range of autoimmune and autoinflammatory disease
Infectious causes

Uveitis may be a (normal) immune response to fight an infection inside the eye. While representing the minority of patients with uveitis, such possible infections include:-

  • Brucellosis
  • Herpes simplex
  • Herpes zoster
  • Leptospirosis
  • Lyme disease
  • Presumed ocular histoplasmosis syndrome
  • Syphilis
  • Toxocariasis
  • Toxoplasmosis
  • Tuberculosis
Uveitis Syndromes

In many cases, uveitis is not associated with a systemic (i.e. extraocular) condition: the inflammation is confined to the eye. In some of these cases, the presentation in the eye is characteristic of a described syndrome, and include the following diagnoses:

  • Acute posterior multifocal placoid pigment epitheliopathy (APMPPE).
  • Birdshot retinochoroidopathy.
  • Fuchs Heterochromic Iridocyclitis.
  • Multifocal Choroiditis and Panuveitis Syndrome.
  • Multiple Evanescent White Dot Syndrome (MEWDS).
  • Punctate Inner Choroidopathy (PIC).
  • Serpiginous Choroiditis.
Masquerade syndromes

Masquerade syndromes are ophthalmic disorders that clinically present as either an anterior or posterior uveitis, but are not primarily inflammatory. The following are some of the most common:

Description of Uveitis

Masquerade syndromes are ophthalmic disorders that clinically present as either an anterior or posterior uveitis, but are not primarily inflammatory. The following are some of the most common:

  • Anterior segment
  • Intraocular foreign body
  • Juvenile xanthogranuloma
  • Leukemia
  • Malignant melanoma
  • Retinal detachment
  • Retinoblastom
  • Posterior segment
  • Lymphoma.
  • Malignant melanoma.
  • Multiple sclerosis.
  • Reticulum cell sarcoma.
  • Retinitis pigmentosa.
  • Retinoblastoma.
Symptoms and Signs

Symptoms and signs may be subtle and vary depending on the site and severity of inflammation.

Anterior uveitistends to be the most symptomatic, usually manifesting with pain (ocular ache), redness, photophobia, and, to a variable degree, decreased vision. Signs include hyperemia of the conjunctiva adjacent to the cornea (ciliary flush or limbal injection). Slit-lamp findings include cells and flare (a haze) in the anterior chamber (aqueous humor), keratic precipitates (WBC clumps on the inner corneal surface), and posterior synechiae. With severe anterior uveitis, WBCs may layer in the anterior chamber (hypopyon).

Intermediate uveitis is typically painless and manifests with floaters and decreased vision. The primary sign is cells in the vitreous humor. Aggregates and condensations of inflammatory cells often occur over the pars plana (near the junction of the iris and sclera), forming snowballs. Vision may be decreased because of floaters or cystoid macular edema, which results from fluid leakage from blood vessels in the macula. Confluent and condensed vitreous cells and snowballs over the pars plana may cause a classic snowbank appearance, which can be associated with neovascularization of the retinal periphery.

Posterior uveitis may give rise to diverse symptoms but most commonly causes floaters and decreased vision as occurs in intermediate uveitis. Signs include cells in the vitreous humor; white or yellow-white lesions in the retina (retinitis), underlying choroid (choroiditis), or both; exudative retinal detachments; retinal vasculitis; and optic disc edema.

Panuveitismay cause any combination of the previously mentioned symptoms and signs.

Consequences:Consequences of uveitis include profound and irreversible vision loss, especially when unrecognized, inadequately treated, or both. The most frequent complications include cataract; glaucoma; retinal detachment; neovascularization of the retina, optic nerve, or iris; and cystoid macular edema (the most common cause of decreased vision in patients with uveitis).

Diagnosis
  • Slit-lamp examination
  • Dilated fundus examination

Uveitis should be suspected in any patient who has ocular ache, redness, photophobia, floaters, or decreased vision. Patients with anterior uveitis have ocular ache in the affected eye if light is shined in the unaffected eye (true photophobia), which is uncommon in conjunctivitis. Diagnosis of anterior uveitis is by recognizing cells and flare in the anterior chamber. Cells and flare are seen with a slit lamp and are most evident when using a narrow, intensely bright light focused on the anterior chamber in a dark room. Findings of intermediate and posterior uveitis are most easily seen after dilating the pupil ,. Indirect ophthalmoscopy is more sensitive than direct ophthalmoscopy.

Many conditions that cause intraocular inflammation can mimic uveitis and should be considered in the appropriate clinical settings. Such conditions include intraocular cancers in the very young (typically retinoblastoma and leukemia) and in the elderly (intraocular lymphoma). Less commonly, retinitis pigmentosa can manifest with mild inflammation, which may be confused with uveitis

Treatment
  • Corticosteroids (usually topical)
  • Cycloplegic-mydriatic drugs

Treatment of active inflammation usually involves corticosteroids given topically or by periocular or intraocular injection along with a cycloplegic-mydriatic drug (eg, homatropine ) . Antimicrobial drugs are used to treat infectious uveitis. Particularly severe or chronic cases may require systemic corticosteroids, systemic noncorticosteroid immunosuppressive drugs, laser phototherapy, cryotherapy applied trans-sclerally to the retinal periphery, or surgical removal of the vitreous (vitrectomy).