CMV (Cytomegalovirus) Retinitis

Medically Reviewed by Jonathan E. Kaplan, MD on November 08, 2022
3 min read

Cytomegalovirus (CMV) retinitis is a viral eye infection. It can be serious and even cause blindness.

You're more likely to get this infection if you have a weak immune system from HIV or AIDS. CMV retinitis used to be very common among people with HIV before HIV drugs came along in the 1990s. But this eye disease still affects a small number of people today. It's a leading cause of blindness in people with AIDS.

CMV is a type of herpesvirus. It infects the retina, the light-sensitive layer of tissue in the back of your eye. The retina converts light that hits your eye into electrical signals so that your brain can interpret the image. You can’t have good vision without a healthy retina.

CMV is a common virus. Over half of adults get it by the time they turn 40. The virus usually doesn't cause problems in healthy people. But if HIV has weakened your immune system, the virus can spread and infect your eye. At the same time, CMV itself can suppress your immune system.

The virus infects and damages cells in your retina, which causes scars to form. It also may prevent blood from supplying your eyes with oxygen. You can catch CMV from someone who has it through body fluids, including saliva, blood, semen, and tears.

CMV retinitis can cause retinal detachment. This is when the retina peels away from the blood vessels that feed it. Without treatment, CMV retinitis can cost you your eyesight. Starting on antiviral medicine right away after your diagnosis can help save your vision.

You may not notice any signs at first. Symptoms often start in one eye. Over time, the virus can also affect the other eye. CMV retinitis is most often diagnosed between ages 20 and 50.

It may cause:

Other eye diseases can cause similar symptoms. If you have any vision problems, call your eye doctor right away.

Your doctor will give you drops to widen your pupils and then examine your retina. Your doctor may also remove a small sample of fluid from your eye to test for the virus. Its recommended that people with HIV get vision checkups every 3 months.

A key way to avoid CMV retinitis is to keep your HIV under control. That means taking your highly active antiretroviral therapy (HAART) medications every day. HAART lowers the amount of HIV in your body. That makes your immune system stronger so it can better fight off invaders like CMV.

Your HIV doctor may test your blood for your CD4 count. CD4 is a type of immune cell. A low CD4 level may be a sign that your immunity is weakened.

Up to 95% of people with CMV retinitis do well with treatment. Antiviral medications include ganciclovir(Cymevene, Cytovene, Vitrasert, Zirgan),  cidofovir (Vistide), foscarnet (Foscavir), and valganciclovir (Valcyte). You can take these medicines in a few ways:

  • As a pill
  • As an injection into a vein
  • As an injection into the eye
  • Through an implant in your eye that slowly releases the medicine over time

CMV can grow resistant to drugs the longer you take them. So the aim is to clear up your retinitis as quickly as possible. If CMV damaged your retina, you might need laser surgery to fix the weakened areas.

CMV is an opportunistic infection. So if your HIV isnt well managed (you have a CD4 count below 50), youre extremely likely to get CMV retinitis again.