Definition: CMV, or cytomegalovirus, retinitis is an infection caused by decreased T-helper cell counts found in HIV-positive individuals. Most patients are asymptomatic unless the optic nerve or macula is involved.
Symptoms: Symptoms of CMV retinitis may include floaters or painless loss of central or peripheral vision.
Although the eyes will always look and feel normal, a thorough dilated retinal examination is needed to diagnose the retinal infection. Diagnosis is based on the clinical findings of hemorrhagic retinal inflammation often following a vascular distribution. If left untreated, the infection will spread throughout the retina and cause blindness.
Retinal detachment is a late cause of vision loss in CMV retinitis, and may develop in eyes with completely inactive infection. The 6-month and 1-year risks of retinal detachment are 11% and 24% respectively.
Treatment: CMV retinitis is a progressive, bilateral, and blinding disease if left untreated. Treatment with antiviral agents is the only effective means for controlling ocular infection. Since all current drugs are virostatic (suppress, rather than kill the virus), they must be given for the life of the patient. Monthly retinal examinations are necessary to monitor the infection and modify treatment when necessary.
The decisions regarding choice of drug and route of administration are multifactor and becoming more complicated as more options become available. Treatment strategies and management are truly a team effort involving the patient, family members, internist, and retinal specialist. Current antiviral options include oral Ganciclovir, intravenous therapy, and localized therapy. All have their distinct advantages and disadvantages and none offer the perfect balance of quality of life, efficacy, safety, and cost.