Cystoid Macular Edema Or CME is a painless disorder which can occur after cataract surgery. The Macula or central area of the retina is responsible for reading vision. After eye surgery the macula can develop swelling just like a sponge can swell with multiple cyst like or Cystoid spaces. CME can occur initially in about one in five eyes after cataract surgery but is only visually significant in 1 to 2% of cases. If CME developed in one eye after cataract surgery than there's about a fifty percent chance of developing it in the other fellow eye after surgery. Other risk factors for the development of CME which may depend upon your general health, underlying conditions of the eye, and the technique of cataract surgery. 80 percent of cases will clear on their own after about one year. Some patients will develop CME immediately after surgery whereas other patients develop delayed CME weeks to months after surgery.

Most cases respond well to eye drops after 1-2 months. In refractory cases, that is patients who don't respond well to drops sometimes an injection of cortisone around the eye can be used. Laser is used to treat abnormal leaking vessels in some cases such as diabetic retinopathy. In more advanced cases of vitrectomy surgery is indicated especially if any ocular abnormalities detected. The best potential visual acuity after the CME resolves depends upon other associated ocular conditions. For example, if the CME resolves, but the patient has advanced macular degeneration, the vision will still be poor.