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  • What is Cytomegalovirus Retinitis?

    Reviewed By Ninel Z Gregori, MD
    Published Apr. 26, 2023

    What is cytomegalovirus retinitis?

    Cytomegalovirus retinitis (CMV retinitis) is a serious viral eye infection of the retina. The retina is the light-sensing layer of cells lines the back of the eye. CMV retinitis is most often found in people with weakened immune systems.

    What are symptoms of CMV retinitis?

    CMV retinitis symptoms can begin with a slow onset of floaters with blurred vision over a few days. This can lead to a loss of peripheral (side) vision. Sometimes the symptoms begin with a blind spot in the center of vision and can lead to a loss of central vision. The symptoms usually happen first in one eye but often progress to the other eye. Without treatment or improvement in the immune system, CMV retinitis destroys the retina and damages the optic nerve. This results in decreased vision or even blindness. People with CMV retinitis will often develop a detached retina (when the retina develops tears and falls off the back of the eye).

    What causes CMV retinitis?

    CMV retinitis is caused by the cytomegalovirus. This is one of the herpes viruses that infects most adults. The vast majority of people who have cytomegalovirus have no symptoms of infection. They will never have any problems because of the virus. But in people with weakened immune systems, the virus can reactivate and spread to the retina. This can lead to vision-threatening eye problems.

    Who is at risk for CMV retinitis?

    CMV retinitis is a significant threat to people with weak immune systems. This includes people such as: 

    • those with HIV/AIDS
    • those undergoing immunosuppressive therapy for cancer/leukemia
    • recipients of organ transplants (including bone marrow transplants). 

    The earliest symptoms of CMV retinitis are floaters with a shadow appearing in the peripheral (side) vision as the disease worsens. Ophthalmologists need to check people with compromised immune systems for the disease.

    HIV, AIDS and CMV retinitis

    Before highly active antiretroviral therapy, CMV retinitis was a common problem for people with AIDS. While it is less common now, people with HIV or AIDS still have a higher risk for CMV retinitis. They should see an ophthalmologist regularly.

    How is CMV retinitis diagnosed?

    Your ophthalmologist will examine your eyes after dilating (widening) your pupils. Your ophthalmologist will look at areas of your eye, including your retina, for signs of CMV retinitis.

    How is CMV retinitis treated?

    Strengthening your immune system is an important part of treating CMV retinitis. People with HIV or AIDS often improve if they are on highly active antiretroviral therapy (HAART).

    There are also specific CMV retinitis treatments. Ganciclovir and other antiviral medicines can be taken in several ways:

    • by mouth
    • through a vein
    • as an eye injection 

    Often your ophthalmologist will need to perform laser surgery. The laser may reduce the risk of the retinal detachment. 

    Although treatments are available, you cannot get back vision lost because of CMV retinitis. Even with treatment, the disease may still progress. Recurrence of CMV retinitis is common, so regular checkups with an ophthalmologist are important.