What is CMV Retinitis?

CMV retinitis is an opportunistic infection of the eye that occurs in people with AIDS. It is caused by cytomegalovirus (CMV) which is a type of herpes virus. Like some other viruses, most people were exposed to CMV many years before their HIV infection. As the immune system weakens, CMV can spread to the retina through the bloodstream. The retina is a membrane lining the inside of the eye, which contains nerve fibers that transfer information about light to the brain. The virus causes inflammation in the retina, which can result in decreased vision or blindness if left untreated. People with CD4 counts lower than 100 are particularly at risk. CMV retinitis is a treatable condition.

What are the symptoms?

Though the symptoms can initially be subtle, people with AIDS need to be aware of the types of visual changes that should be investigated promptly. These include:

Sudden changes in vision. Sudden changes in vision need to be investigated promptly by an ophthalmologist. Gradual changes in vision often indicate normal, age-related problems such as need for reading glasses or change in the prescription of glasses or contacts.

Significant increase in the number of "floaters" or "flashing lights." Floaters are transparent or dark material floating and moving in your field of vision. A few floaters are normal and can be seen by most people when looking at the blue sky or other plain backgrounds.

Distortion or absence of an area in the field of vision. This may appear as an area of blurred vision or an area of your vision that is missing.

How is CMV Retinitis Detected?

CMV retinitis can arise quickly and progress rapidly. If your CD4 count is lower than 150, you should have a dilated retinal exam performed by your ophthalmologist on a regular basis. Although your health care provider will look at the retina during an examination, it is very important for you to be aware of your vision and report any visual changes. Sudden changes should be evaluated promptly by an ophthalmologist. This examination requires dilation of the pupils with eye drops in order to see more of the retina. Gradual changes in vision or problems focusing should be checked by an optometrist to ensure that these changes are related to a correctable eyeglass prescription problem.

Amsler Grid

In addition to being aware of visual symptoms, you can also check your vision by using an Amsler Grid at home. Sudden changes in the appearance of the amsler grid should be evaluated promptly by an ophthalmologist.