Cystoid macular edema is swelling caused by fluid inside the eye that affects vision. It rarely causes permanent loss of vision, but the process of healing is slow. For most people, treatment and recovery will take anywhere from 2 to 15 months before they will regain eye health and normal vision.
The macula is a small yellow spot in the center of the retina where incoming images focus. Cystoid macular edema (CME) results when cyst-like areas of fluid accumulate in the macula and cause swelling (edema) in the retina.
One cause of CME is eye surgery, including cataract removal and retinal reattachment. If CME develops after cataract surgery, it’s called Irvine-Gass syndrome. A paper published by Dr. David Telander and Dr. Christopher Cessna at the University of California Davis School of Medicine stated that about 1 percent of the people who had cataract surgery would get CME. Dr. Daniel Roth from the University of Medicine and Dentistry of New Jersey stated that the incidence of CME after retinal reattachment surgery ranged from 30 percent to 43 percent.
Other causes include diabetes (diabetic retinopathy), age related macular degeneration, injury to the eye, inflammation, drug toxicity, and blockages in the veins or arteries. These cause damage to the blood vessels, they begin to leak fluid, and the result is macular edema. CME that is caused by diabetes, vein blockage or uveitis (inflammation) tends to last a long time and will have periods of remission mixed with times when it will flare-up.
The symptoms of CME are blurry or wavy vision appearing right in the middle of the field of vision. It’s possible for colors to look a little different and your eye may be sensitive to light.
Any underlying condition that is causing the CME must be appropriately treated first. If the CME is caused by retinal inflammation, then anti-inflammatory medication is prescribed. Corticosteroids are usually the primary treatment, but other medications such as nonsteroidal anti-inflammatory drugs may be prescribed. These can be given as eyedrops or even injected directly into the eye for a more concentrated effect.
Surgery may be necessary if the CME is chronic, does not respond to medications or is being caused by problems with structures inside the eye. Two types of surgery—vitrectomy and laser—may be considered. Laser surgery is commonly used if the cause is diabetic retinopathy because the lasers slow leakage and reduce the amount of fluid in the retina.
The inflammation that is caused by CME can sometimes cause glaucoma, which must then be treated with medications. Chronic CME can cause permanent damage to central vision.