Usually immunologic but possibly infective or neoplastic
Acute nongranulomatous anterior uveitis: pain, redness, photophobia, and visual loss
Granulomatous anterior uveitis: blurred vision in a mildly inflamed eye
Posterior uveitis: gradual loss of vision in a minimally inflamed eye
General Considerations
Intraocular inflammation (uveitis) is classified as acute or chronic and as nongranulomatous or granulomatous, according to the clinical signs, and by its involvement of the anterior, intermediate, posterior, or all (panuveitis) segments of the eye The common types are acute nongranu- lomatous anterior, granulomatous anterior, and posterior In most cases the pathogenesis of uveitis is primarily immunologic, but infection may be the cause, particularly in immunodeficiency states The systemic disorders associated with acute nongranulomatous anterior uveitis are the HLA-B27-related conditions (ankylosing spondylitis, reactive arthritis, psoriasis, ulcerative colitis, and Crohn disease) Chronic nongranulomatous anterior uveitis occurs in juvenile idiopathic arthritis Behçet syndrome produces both anterior uveitis, with recurrent hypopyon but little discomfort, and posterior uveitis, characteristically with branch retinal vein occlusions Both herpes simplex and herpes zoster infections may cause nongranulomatous anterior uveitis as well as retinitis (acute retinal necrosis) Diseases producing granulomatous anterior uveitis also tend to be causes of posterior uveitis These include sarcoidosis, toxoplasmosis, tuberculosis, syphilis, Vogt Koyanagi-Harada disease (bilateral uveitis associated with alopecia, poliosis [depigmented eyelashes, eyebrows, or hair], vitiligo, and hearing loss) , and sympathetic ophthalmia that occurs after penetrating ocular trauma In toxoplasmosis, there may be evidence of previous episodes of retinochoroiditis Syphilis characteristically produces a “salt and pepper” fundus but may present with a wide variety of clinical manifestations The other principal pathogens responsible for ocular inflammation in HIV infection are cytomegalovirus (CMV), herpes simplex and herpes zoster viruses, mycobacteria, Cryptococcus, Toxoplasma, and Candida Retinal vasculitis and intermediate uveitis predomi- nantly manifest as posterior uveitis with central or peripheral retinal abnormalities in retinal vasculitis and far peripheral retinal abnormalities (pars planitis) in intermediate uveitis Retinal vasculitis can be caused by a wide variety of infectious agents and noninfectious systemic conditions but also may be idiopathic Intermediate uveitis is often idiopathic but can be due to multiple sclerosis or sarcoidosis
Clinical Findings
Anterior uveitis is characterized by inflammatory cells and flare within the aqueous In severe cases, there may be hypopyon (layered collection of white cells) and fibrin within the anterior chamber Cells may also be seen on the corneal endothelium as keratic precipitates (KPs) In granulomatous uveitis, there are large “mutton-fat” KPs, and sometimes iris nodules In nongranulomatous uveitis the KPs are smaller with no iris nodules The pupil is usually small, and with the development of posterior synechiae (adhesions between the iris and anterior lens capsule) it also becomes irregular Nongranulomatous anterior uveitis tends to present acutely with unilateral pain, redness, photophobia, and visual loss However, in juvenile idiopathic arthritis there tends to be an indolent, often initially asymptomatic process with a high risk of sight-threatening complications Granulomatous anterior uveitis is usually indolent, causing blurred vision in a mildly inflamed eye In posterior uveitis, there are cells in the vitreous and there may be inflammatory retinal or choroidal lesions Fresh retinal lesions are yellow with indistinct margins and there may be retinal hemorrhages, whereas older lesions have more definite margins and are commonly pigmented Retinal vessel sheathing may occur adjacent to such lesions or more diffusely In severe cases, vitreous opacity precludes visualization of retinal details Posterior uveitis tends to present with gradual visual loss in a minimally inflamed eye Bilateral involvement is common Visual loss may be due to vitreous haze and opacities, inflammatory lesions involving the macula, macular edema, retinal vein occlusion, or rarely optic neuropathy
Differential Diagnosis
Retinal detachment, intraocular tumors, and central nervous system lymphoma may all masquerade as uveitis
Treatment
Anterior uveitis usually responds to topical corticoste- roids Occasionally periocular corticosteroid injections or even systemic corticosteroids are required Dilation of the pupil is important to relieve discomfort and prevent permanent posterior synechiae Posterior uveitis more com- monly requires systemic, periocular, or intravitreal corticosteroid therapy and occasionally systemic immunosuppression with agents such as azathioprine, cyclosporine, mycophenolate, methotrexate, tacrolimus, or sirolimus, of which some can be administered by intraocular injection The use of biologic therapies is increasing Pupillary dilation is not usually necessary If an infectious cause is identified, specific antimicrobial therapy is often needed In general, the prognosis for anterior uveitis, particularly the nongranulomatous type, is better than for posterior uveitis
When to Refer
Any patient with suspected acute uveitis should be referred urgently to an ophthalmologist or emergently if visual loss or pain is severe
Any patient with suspected chronic uveitis should be referred to an ophthalmologist, urgently if there is more than mild visual loss
When to Admit Patients with severe uveitis, particularly those requiring intravenous therapy, may require hospital admission