A number of infectious diseases cause uveitis (see Table 1: Uveitis and Related Disorders: Infectious Causes of Uveitis). The most common are herpes simplex virus, varicella-zoster virus, and CMV infection and toxoplasmosis. Different organisms affect different parts of the uveal tract.

Table 1
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Infectious Causes of Uveitis Frequency Viruses or Infections More common Cytomegalovirus* Herpes simplex virus Pneumocystis jirovecii* Toxoplasmosis Varicella-zoster virus Less common Bartonellosis Histoplasmosis Lyme disease Syphilis Toxocariasis Tuberculosis Rare Aspergillus Candida Coccidioidomycosis Cryptococcus Cysticercosis Leprosy Leptospirosis Onchocerciasis Tropheryma whippelii *Particularly in patients with AIDS.

Herpesvirus: Herpes simplex virus (see also Herpesviruses: Herpes Simplex Virus (HSV) Infections) causes anterior uveitis. Varicella-zoster virus does so less commonly, although the prevalence of zoster-associated anterior uveitis increases with age. Symptoms include ocular aching, photophobia, and decreased vision. Signs include redness; conjunctival injection and anterior chamber inflammation (cells and flare), often accompanied by corneal inflammation (keratitis); decreased corneal sensation; and patchy or sectorial iris atrophy. Intraocular pressure may be elevated as well; elevation can be detected by using applanation tonometry with a Schiotz tonometer, a Goldmann tonometer, or a pneumotonometer.

Treatment should generally be initiated by an ophthalmologist and should include a topical corticosteroid and a cycloplegic-mydriatic drug. AcyclovirSome Trade Names
ZOVIRAX
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(400 mg po 5 times/day for herpes simplex virus and 800 mg po 5 times/day for herpes zoster virus) may also be given. Drops to lower intraocular pressure may be required in patients with ocular hypertension.

Much less commonly, varicella-zoster and herpes simplex viruses cause a rapidly progressing form of retinitis called acute retinal necrosis (ARN), which typically manifests as confluent retinitis, occlusive retinal vasculitis, and moderate to severe vitreous inflammation. One third of ARN cases become bilateral, and in three fourths of eyes, retinal detachment occurs. ARN may also occur in patients with HIV/AIDS, but severely immunocompromised patients can have less prominent vitreous inflammation. Vitreous biopsy for culture and PCR analysis may be useful in diagnosing ARN. Treatment options include IV acyclovirSome Trade Names
ZOVIRAX
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, IV ganciclovirSome Trade Names
CYTOVENE
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or foscarnetSome Trade Names
FOSCAVIR
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, intravitreal ganciclovirSome Trade Names
CYTOVENE
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or foscarnetSome Trade Names
FOSCAVIR
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, and oral valacyclovirSome Trade Names
VALTREX
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or valganciclovirSome Trade Names
VALCYTE
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.

Retinitis (Herpes)

Toxoplasmosis: Toxoplasmosis (see also Extraintestinal Protozoa: Toxoplasmosis) is the most common cause of retinitis in immunocompetent patients. Most cases are acquired postnatally; however, congenital cases occur as well, particularly in countries where infection is endemic. Symptoms of floaters and decreased vision may be due to cells in the vitreous humor or to retinal lesions or scars. Concurrent anterior segment involvement can occur and may cause ocular ache, redness, and photophobia. Laboratory testing should include serum anti-Toxoplasma gondii antibody titers.

Treatment is recommended for patients with posterior lesions that threaten vital visual structures, such as the optic disk or macula, and for immunocompromised patients. Multidrug therapy is commonly prescribed; it includes pyrimethamineSome Trade Names
DARAPRIM
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, sulfonamides, clindamycinSome Trade Names
CLEOCIN
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, and, in select cases, systemic corticosteroids. Corticosteroids should not, however, be used without concurrent antimicrobial coverage. Long-acting periocular and intraocular corticosteroids (eg, triamcinoloneSome Trade Names
ARISTOCORT
KENACORT
KENALOG
NASACORT
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acetonide) should be avoided. Patients with small peripheral lesions that do not directly threaten vital visual structures may be observed without treatment and should begin to show slow improvement in 1 to 2 mo.

Retinitis (Toxoplasmosis)

Cytomegalovirus: CMV (see also Herpesviruses: Cytomegalovirus (CMV) Infection) is the most common cause of retinitis in immunocompromised patients, but prevalence has decreased among patients with HIV/AIDS receiving highly active antiretroviral therapy (HAART). Currently, ≤ 5% of these patients are affected. Most affected patients have a CD4+ count < 100 cells/μL. CMV retinitis may also occur in neonates and in pharmacologically immunosuppressed patients but is uncommon.

The diagnosis is largely clinical based on direct or indirect ophthalmoscopic examination; serologic tests are of limited use. Treatment in patients with HIV/AIDS is with systemic or local (implant) ganciclovirSome Trade Names
CYTOVENE
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, systemic foscarnetSome Trade Names
FOSCAVIR
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, or valganciclovirSome Trade Names
VALCYTE
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. Therapy is typically continued indefinitely, unless immune reconstitution is achieved with combination antiretroviral therapy (typically a CD4+ count > 100 cells/μL for at least 3 mo).

Retinitis (Cytomegalovirus)

Last full review/revision September 2012 by Emmett T. Cunningham, Jr., MD, PhD, MPH

Content last modified November 2012