Chorioretinitis

Multifocal Choroiditis (MC)

Multifocal choroiditis usually affects women in their 40s. Patients present with metamorphopsia or bilateral, subacute decrease in central vision. Vitritis may be present in one or both eyes. The characteristic fundus appearance includes several yellow to gray lesions at the level of the retinal pigment epithelium that are round or oval in shape and can be seen alone, in clusters or in a linear configuration. These lesions eventually become round and atrophie. Fibrosis and subretinal neovascularization are common complications.

Management: Periocular or systemic corticosteroids have been used to treat MC, although the best therapy is still unclear. Angiography is needed to monitor for subretinal neovascularization that may respond to treatment with laser photocoagulation or verteporfin therapy.

Presumed Ocular Histoplasmosis Syndrome

In presumed ocular histoplasmosis syndrome, serous and hemorrhagic detachments of the macula due to subretinal neovascularization are associated with multiple peripheral atrophie chorioretinal scars and peripapillary chorioretinal scarring.

This usually occurs in healthy, young patients between the ages of 30 and 60 and is due to a preceding subclinical infection with Histoplasma capsulatum. Patients may have a history of living in the Midwest where this condition is common.

Management: Argon laser photocoagulation of subretinal neovascularization outside the foveal avascular zone may help preserve vision in symptomatic patients.

Verteporfin (Visudyne) photodynamic therapy is used for subfoveal choroidal neovascularization (CNV). Surgical removal of submacular membranes may be necessary to prevent vision loss.

All patients should be instructed to use an Amsler grid bilaterally and report changes promptly.

Vitiliginous Chorioretinitis (Birdshot Retinochoroidopathy)

Diffuse cream-colored patches and retinal vasculitis are associated with cystoid macular edema and vitritis. The disease course waxes and wanes with visual acuity changing due to edema, scarring and subretinal neovascularization. Patients may have a genetic predisposition.

Management: Treatment includes immunosuppression with systemic steroids and anti-inflammatory medications. Close monitoring with angiography may be necessary to detect and treat neovascularization and its sequelae.

Toxoplasma Chorioretinitis

Toxoplasma chorioretinitis is the result of Toxoplasma gondii, a congenitally acquired, bilateral, protozoan infection. Retinal vasculitis and focal necrotic retinochoroiditis (fluffy white areas) are seen. Active edematous lesions often are adjacent to old, healed lesions.

Episodes of posterior uveitis and chorioretinitis usually herald reactivation of a latent, congenital infection. Patients usually present with floaters, blurred vision, pain or photophobia. Peripheral vision is preserved but, because of frequent macular involvement, central vision may be reduced.

Management: A serologie test for Toxoplasma gondii may be necessary for diagnosis. Small lesions in the retinal periphery generally do not require treatment.

However, large, severe or posteriorly located lesions are treated with trisulfapyrimidine (Terfonyl) and pyrimethimine or clindamycin (Cleocin). Subretinal neovascularization may be treated with argon laser photocoagulation.

Copyright Boucher Communications, Inc. Sep 2005
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