uveitis Haneen Omar Abu Hani

Definition Uveitis is the Inflammation of the uveal tract (the iris, ciliary body and choroid). It is usual for structures adjacent to the inflamed uveal tissue to become involved in the inflammatory process.

It may be classified anatomically: • Inflammation of the iris, accompanied by increased vascular permeability, is termed iritis or anterior uveitis. • An inflammation of the ciliary body is termed cyclitis, of the pars plana is pars planitis and of the vitreous is vitritis. As a group these are termed intermediate uveitis. • Inflammation of the posterior uvea is termed posterior uveitis and may involve the choroid ( choroiditis) , the retina ( retinitis) or both (chorioretinitis). • A panuveitis is present when inflammatory changes affect the anterior chamber, vitreous and retina and/or the choroid.

Epidemiology The incidence of uveitis is about 15 per 100 000 people. About 75% of these are anterior uveitis. About 50% of patients with uveitis have an associated systemic disease.

History The patient may complain of: • ocular pain (less frequent with posterior uveitis or choroiditis); • photophobia; • blurring of vision; • redness of the eye. Posterior uveitis may, however, not be painful.

The patient must be questioned about other relevant symptoms that may help determine whether or not there is an associated systemic disease: • Respiratory symptoms such as shortness of breath, cough, and the nature of any sputum produced (associated sarcoidosis or tuberculosis). • Skin problems: Erythema nodosum (painful raised red lesions on the arms and shins) may be present in granulomatous diseases such as sarcoidosis and Behçet’s disease. Patients with Behçet’s may also have thrombophlebitis, dermatographia and oral and genital ulceration. Psoriasis (in association with arthritis) may be accompanied by uveitis. • Joint disease: Ankylosing spondylitis with back pain is associated with acute anterior uveitis. In children juvenile chronic arthritis may be associated with uveitis. Reiter’s disease (classically urethritis, conjunctivitis and a seronegative arthritis) may also be associated with anterior uveitis.

• Bowel disease. Occasionally uveitis may be associated with inflammatory bowel diseases such as ulcerative colitis, Crohn’s disease and Whipple’s disease. • Infectious disease. Syphilis with its protean manifestations can cause uveitis (particularly posterior choroiditis). Herpetic disease (herpes simplex and zoster) may also cause uveitis. Cytomegalovirus (CMV) may cause uveitis, particularly in patients with AIDS. Fungal infections and metastatic infections may also cause uveitis, usually in immunocompromised patients.

SIGNS On examination: • The visual acuity may be reduced. • The eye will be inflamed, mostly around the limbus (ciliary injection). Intermediate and Posterior uveitis • There may be cells in the vitreous. • There may be retinal or choroidal foci of inflammation. • Macular oedema may be present.

Anterior uveitis • Inflammatory cells may be visible clumped together on the endothelium of the cornea, particularly inferiorly (keratitic precipitates or KPs). ‘Pic a’ • The iris may adhere to the lens and bind down the pupil ( posterior synechiae or PS ). Peripheral anterior synechiae (PAS) between the iris and the trabecular meshwork or cornea may occlude the drainage angle. ‘pic b’

• Slit- lamp examination will reveal aqueous cells and a flare due to exuded protein. If the inflammation is severe there may be sufficient white cells to collect as a fluid level inferiorly (hypopyon). ‘picture c’ • The vessels on the iris may be dilated. • The intraocular pressure may be elevated by PAS or increased aqueous protein.

Investigations These are aimed at determining a systemic association and are directed in part by the type of uveitis present. An anterior uveitis is more likely to be associated with ankylosing spondylitis, and human leucocyte antigen (HLA) typing may help confirm the diagnosis. The presence of large KPs and possibly nodules on the iris may suggest sarcoidosis: a chest radiograph, serum calcium and serum angiotensin - converting enzyme levels would be appropriate. In toxoplasmic retinochoroiditis the focus of inflammation often occurs at the margin of an old inflammatory choroidal scar. A posterior uveitis may have an infectious or systemic inflammatory cause. Some diseases such as CMV infections in HIV - positive patients have a characteristic appearance, and with an appropriate history may require no further diagnostic tests. Associated symptoms may also point towards a systemic disease (e.g. fever, diarrhoea, weight loss). Not all cases of anterior uveitis require investigation at first presentation unless associated systemic symptoms are present.

Treatment This is aimed at: • suppressing inflammation in the eye, and relieving pain in anterior uveitis; • preventing damage to ocular structures, particularly to the macula and the optic nerve, which may lead to permanent visual loss.

Treatment 1.Steroids therapy: is the mainstay of treatment. In anterior uveitis this is delivered by eye drops. However, topical steroids do not effectively penetrate to the posterior segment. Posterior uveitis is therefore treated with systemic steroids, or with steroids injected onto the orbital floor or into the sub –Tenon’s space. ‘the adjacent figure’

2. Mydriatics, e. g. cyclopentolate or atropine drops 2. Mydriatics, e.g. cyclopentolate or atropine drops. In anterior uveitis, dilating the pupil relieves the pain from ciliary spasm and prevents the formation of posterior synechiae by separating it from the anterior lens capsule. Synechiae otherwise interfere with normal dilation of the pupil. 3. antiviral or antibiotic medication may also be required. 4. other systemic immunosuppressive drugs such as azathioprine or ciclosporin.