Cystoid Macular Edema

What is Cystoid macular edema?

Cystoid macular edema, commonly called CME, is a painless disorder which affects the central retina or macula. When this condition is present, multiple cyst-like (cystoid) areas of fluid appear in the macula and cause retinal swelling or edema.

Although the exact cause of CME is not known, it may accompany a variety of diseases such as retinal vein occlusion, uveitis, or diabetes. It most commonly occurs after cataract surgery. About 1-3 % of those who have cataract extractions will experience decreased vision due to CME during the first post-operative year, usually from two to four months after surgery. If the disorder appears in one eye, there is an increased risk (possibly as high as 50%) that it will also affect the second eye. Fortunately, however, most patients recover their vision with treatment.


  • Blurred or decreased central vision (the disorder does not affect peripheral or side-vision)
  • Painless retinal inflammation or swelling (usually after cataract surgery)

The symptoms described above may not necessarily mean that you have cystoid macular edema. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.


Because many factors can lead to CME, effective treatment will vary. After the diagnosis has been made and confirmed, your ophthalmologist may attempt several kinds of treatment. Retinal inflammation is usually treated with anti-inflammatory medications such as cortisone or indomethacin. These are usually given as eye drops, though occasionally they must be administered as an injection or by mouth. Diuretics such as diamox may help to reduce the swelling in some cases.

Sometimes, the vitreous (the gel that fills most of the eye) pulls on the macula causing CME. A vitrectomy (surgery to remove the vitreous gel) is done in those situations if needed.

In some cases, the swelling and inflammation which accompanies CME can cause glaucoma, a disorder which often occurs due to increased pressure inside the eye. If this happens, the glaucoma must be treated with appropriate medications to reduce the pressure.

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