Immunosuppressed patients are at risk for developing
cytomegalovirus retinitis. This disorder is the most common cause of vision loss in patients with the
acquired immunodeficiency syndrome (
AIDS).
Cytomegalovirus retinitis is probably the result of hematogenous spread of the virus to the retina after systemic reactivation of a latent
cytomegalovirus infection. Although the ophthalmic
infection may initially be asymptomatic, the
retinal necrosis it produces may result in both loss of visual field and decreased visual acuity. Routine screening of these patients is required for early diagnosis. The
retinitis is detected with ophthalmoscopy as either a perivascular yellow-white
retinal lesion frequently associated with
retinal hemorrhage or as a focal white granular infiltrate, often without
hemorrhage. Both lesions enlarge in a progressively expanding "brushfire" pattern. The diagnosis of
cytomegalovirus retinitis, as well as the evaluation of its response to
therapy, is determined primarily by clinical criteria. Serial
retinal photography is an objective method to assess the changing appearance of these lesions.
Ganciclovir and
foscarnet are investigational
antiviral drugs that appear to be effective in treating
cytomegalovirus retinitis. However, maintenance
therapy with these medications is required after initial treatment because the disease often relapses. The combined expertise of the internist and the ophthalmologist is needed to diagnose and treat these patients.