Diabetic macular edema

Diabetic macular edema (DME) is caused by diabetes mellitus. DME is the most common cause of significant deterioration of vision and occurs in approximately 20% of patients affected by diabetes.

Diabetic macular edema occurs when fluid accumulates in the retinal center. If  blood glucose values are chronically increased, the inner layer of retinal vessels become permeable to liquids.  Proteins and fat are deposited and thus contribute to a thickening of the retina.

Additional risk factors for DME are smoking, increased blood fat or blood pressure. In diabetics, a combination of several risk factors is often present, which makes diabetes patients particularly vulnerable. There is a risk of DME in both forms of diabetes, type 1 and type 2.

How can diabetic macular edema be detected ?

Early diagnosis is crucial for an effective therapy. Therefore regular eye exams are recommended for every patient with diabetes, at least once a year.

Eye examination may include:

• visual acuity test

• contrast sensitivity

• qualitative (Amsler chart) or quantitative tests for distortions (AMD - A Metamorphopsia Detector^®)

• slit lamp examination

• examination of the retina with dilated pupil or retina laser scanning photograph

• fluorescein angiography (FAG): FAG  is an imaging method of the retina. After dilating the pupils with eyedrops, the inflow and distribution of an intravenously applied dye (fluorescein or indocyanine green) is documented. The insights gained can contribute to planning therapy.

• optical coherence tomogaphy (OCT): OCT is a noncontact method in which light is used to  scan eye structures, for example the retina and the optic nerve. High-resolution spectral domain OCT technology can make subtle changes visible.

The most common therapy of diabetic macular edema consists of intravitreal injections: Anti-VEGF or corticosteroids are injected into the vitreous during a short operation, the eye is anesthesized by drops. These injections usually have to be applied several times. In selected cases therapy with laser or an operation (vitrectomy) may be applied. No therapeutic option is available if  ischemic diabetic macular edema is present.

Adjustment of blood glucose levels and blood pressure are essential.