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, is covered with special nerve cells that react to light.
In the center of the retina is a special area called the macula. The macula is right in the middle of the image being focused by the lens, and it is where we usually can see best. 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 coalesces in cyst-like patterns and the 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
- Age-related macular degeneration
- Blockage in the small arteries or veins of the retina
- Inflammation of the eye
- Injury to the eye
- Side effects of medication
How does the doctor know if someone has cystoid macular edema?
The first symptom of cystoid macular edema is blurry or "wavy" vision, usually in the middle of the field of view. Colors might also look different through an eye with cystoid macular edema.
The only way your doctor can be sure these changes in vision are caused by cystoid macular edema is to examine the eye carefully. A special instrument is used to look inside the eye at the macula.
Sometimes it is not obvious, however, that the macula is swollen with fluid. To make sure, your doctor might also order a test called a fluorescein angiogram. The doctor uses a special camera that takes pictures of the macula using ultraviolet light. These pictures will show any areas where fluid has collected in the macula. Your doctor may also order another test called an optical coherence tomography scan that provides a cross-sectional view of the retina.
How is cystoid macular edema treated?
Only an eye doctor can recommend the right treatment for someone with cystoid macular edema. Fortunately, normal vision may return after cystoid macular edema is treated. If the cystoid macular edema is being caused by some other condition such as diabetes, that condition will have to be treated first. If it seems to be the side effect of a medication, the doctor might change that prescription.
When cystoid macular edema occurs after eye surgery or seems to be related to some type of eye injury or inflammation, the doctor will often prescribe an anti-inflammatory medication. This could be in the form of pills, eye drops, or steroid injections around or into the eye.
No matter what is causing cystoid macular edema or what treatment the doctor recommends, it will probably take several months to go away. The patient should not get discouraged. It is important to keep following the doctor’s recommendations, even if it seems like the treatment is not working at first. Eventually, the treatments often work and can restore good vision.