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Diabetic Macular Edema (DME) Fact Sheet

Approximately 26 million people in the U.S. have diabetes.1 People with diabetes are at an increased risk for developing eye problems. One reason is because diabetes and other complications can cause damage to the blood vessels of the retina (diabetic retinopathy).

Diabetic macular edema (DME) is a serious eye condition that affects people with diabetes (type 1 or type 2). "Macular" refers to the macula, which is the central portion of the retina and the part of the eye responsible for sharp central vision.2 Edema means swelling of tissues from fluid.

DME results when the damaged blood vessels leak fluid and cause swelling, which blurs vision. If retinopathy worsens, the eye may begin to form new, abnormal blood vessels over the retina, which can break easily and bleed, causing severe vision loss and even blindness.2,3,4 DME can occur at any stage of diabetic retinopathy, although it is more likely to occur
as the disease progresses.2

Types of DME

  • DME can be broadly characterized into two main anatomic categories - Focal and Diffuse:
    • Focal DME is characterized by specific areas of separate and distinct leakage in the macula with sufficient macular blood flow.4
    • Diffuse DME results from leakage of the entire capillary bed surrounding the macula, resulting from a breakdown of the inner blood-retina barrier of the eye.5
  • In addition to Focal and Diffuse, DME is also categorized based on clinical exam findings into clinically significant macular edema (CSME), non-CSME and CSME with central involvement (CSME-CI), which involves the fovea.

Prevalence of DME

  • DME is a leading cause of vision loss among the working-age population of most developed countries.6
  • More than 560,000 Americans have DME7
  • Approximately 55 percent are unaware that they have the disease.7
  • Approximately 70 percent of patients with the most severe form of diabetic retinopathy, proliferative retinopathy, will develop DME.5

Symptoms and Diagnosis of DME

  • Symptoms of DME include blurred vision, double vision, loss of contrast and floaters patches of vision loss, which may appear as small black dots or lines "floating" across the front of the eye.2
  • In order to diagnose diabetic macular edema, a physician will perform a comprehensive eye exam that includes: a visual acuity test, which determines the smallest letters a person can read on a standardized chart, a dilated eye exam in which drops are placed in the eyes to widen the pupils in order to check for signs of the disease, imaging tests such as optical coherence tomography (OCT) or fluorescein angiography (FA) and tonometry, an instrument that measures pressure inside the eye.2

DME Risk Factors

  • All people with type 1 or type 2 diabetes are at risk for DME.2
  • The risk for developing DME is closely associated with the length of time a patient has lived with diabetes and the severity of diabetic retinopathy.2,3 Poor control of blood sugar also increases the risk of developing DME.8