Macular edema is the swelling of the macula, the small area of the retina responsible for central vision. The edema is caused by fluid leaking from retinal blood vessels. Central vision, used for reading and other close detail work, is affected. Macular edema is painless and most times the patient is not aware of it unless there is decrease in vision.
Because the macula is surrounded by many tiny blood vessels, anything affecting them, such as a medical condition affecting blood vessels elsewhere in the body or an abnormal condition originating in the eye, can cause macular edema. These include diabetes, retinal vein occlusion, macular degeneration or uveitis.
The macula may also be affected by swelling following cataract extraction, though typically this resolves itself naturally. If there is macular edema in one eye, there is an increased risk that it will also affect the second eye. Fortunately, most patient recover their vision after some time.
The most common symptom of macular edema is blurred or decreased central vision (macular edema does not affect peripheral or side vision). However, the condition may be present even when no visual loss occurs.
Since many factors can lead to macular edema, it not possible to say which treatment will prove effective. Signs of retinal inflammation are usually treated with anti-inflammatory medications, including steroid eyedrops, laser therapy or injections into the eye.
In some cases, the swelling and inflammation which accompanies macular edema can bring on glaucoma, a disorder that often occurs due to increased pressure within the eye.
A great deal of research is presently being conducted to determine the causes of macular edema, as well as the best treatment.
It is very important to have periodic eye exams with an ophthalmologist if you suffer from diabetes, high blood pressure, high cholesterol or arthritis.