What is cystoid macular edema?

The eye is often compared to a camera. The front of the eye contains a lens that focuses images on the inside of the back surface of the eye. This surface, called the retina, consists of special nerve cells that react to light.

In the center of the retina is the macula. The macula makes up the center of our vision and is the most critical area for our best visual acuity (sharpness). Sometimes the macula becomes swollen with fluid. When any tissue of the body becomes swollen with fluid, the condition is called edema. When this happens to the macula, the edema fluid typically combines in cyst-like patterns; this condition is called cystoid macular edema.

Why do people get cystoid macular edema?

There are many known causes of cystoid macular edema. These include:

• Eye surgery, including cataract surgery and repair of a detached retina
• Diabetes
• Age-related macular degeneration
• Blockage in veins of the retina (e.g., retinal vein occlusion)
• Inflammation of the eye
• Injury to the eye
• Side effects of medications

What are the symptoms of cystoid macular edema?

Cystoid macular edema can be asymptomatic (no symptoms). Potential symptoms of cystoid macular edema include blurry or "wavy" vision, usually in the middle of the field of view. Colors might also appear different.

How is cystoid macular edema diagnosed?

Cystoid macular edema is usually diagnosed in one of three ways: dilated retinal exam, fluorescein angiography, or optical coherence tomography (OCT).

• Dilated retinal exam: Your doctor may be able to diagnose the cystoid macular edema using a special lens to see the macula and identify the cysts.
• Fluorescein angiography: Alternatively, diagnostic testing may be used to diagnose cystoid macular edema. Fluorescein angiography uses a special camera system to see leakage that results from blood vessels and the associated cystoid macular edema.
• Optical coherence tomography (OCT): OCT has become one of the best ways to diagnose and identify cystoid macular edema. OCT is a non-invasive test that uses a special light to create a high-resolution cross-sectional image of the tissues of interest, including the retina.

How is cystoid macular edema treated?

Only an eye doctor can recommend the right treatment for someone with cystoid macular edema. Often, treatment and evaluation may be needed with a retina specialist. Fortunately, normal vision may return after cystoid macular edema is treated.

It is important to identify the underlying cause of the cystoid macular edema. The best treatment may vary based on any related condition. Depending on the underlying condition, treatment options may include topical therapy, or periocular or intraocular injections.

Successful treatment of the edema may take time. In many cases, visual acuity improves. Even after the edema goes away, the patient needs to see his or her eye doctor on a regular basis to make sure it doesn’t come back.