What is Diabetic Macular Edema?

Diabetic macular edema (DME) is a complication of diabetes.¹ It is a condition with fluid from leaky blood vessels collecting in the macula of the eye, causing swelling.² The macula is the central part of the retina responsible for focused detail vision used in close work, reading and driving. DME develops after the onset of diabetic retinopathy, an eye disease in which pressure builds up in the macula and leaks fluid, causing damage to blood vessels in the retina causing vision distortion.²

What causes diabetic macular edema?

Diabetes is a leading cause of blindness and nearly 10% of diabetics may experience DME.³ DME can develop in people with type 1 or type 2 diabetes. The condition can progress slowly and generally makes it difficult to focus.

There are multiple contributing factors for developing DME. People with diabetes having one or more of the following are at increased risk for developing DME^2,3:

• Living with diabetes for 20+ years
• Poor glucose control
• Very high blood pressure
• Fluid retention
• Hypoalbuminemia (low levels of protein in body fluids)
• Hyperlipidemia (high levels of fats in the blood)
• Kidney disease
• Pregnancy

What is diabetic retinopathy?

(https://maculardegeneration.net/clinical/diabetic-retinopathy/)
A precursor to DME, a majority of diabetics who have had the disease for 20 years or more will experience some diabetic retinopathy. This includes all type 1, and more than half of those with type 2 diabetes.³ Damage to small blood vessels can be correlated with high blood sugar and inconsistent glucose control. When these small blood vessels are damaged, resulting in swelling, leaking or bleeding, vision can be diminished. This process of deterioration is called diabetic retinopathy.³

Types of diabetic macular edema

There are two types of diabetic macular edema:

• Focal DME is characterized by abnormalities in the blood vessels in the eye.
• Diffuse DME is due to the widening or swelling of retinal capillaries, very thin blood vessels in the eyes.²

Symptoms of DME

Common vision changes that are symptoms of DME include:

• Blurry or wavy vision
• Double vision
• Floaters
• Changes in viewing colors
• Blindness, if left untreated^1,2

How is diabetic macular edema diagnosed?

DME is diagnosed during a comprehensive eye exam. First, your central vision will be evaluated to identify any changes in visual acuity. The eye is dilated with eye drops that widen the pupil and enable the doctor to take a more detailed look inside the eye.³ There are additional tests that can be performed to further evaluate DME.

OCT test

Optical coherence tomography (OCT) is an imaging test that shows cross-sectional views of the eye. These images can show if the macula is leaking fluid or thickened.

Fluorescein angiography

Dye injected into a vein in the arm circulates through the blood to highlight the vessels in the eye. Photographs taken of the back of the eye can indicate if new blood vessels are growing or if the dye is leaking, helping doctors to determine if DME is present.

Treatment for DME

While there are several treatments that can be used in treating macular edema, there is no cure.

Anti-VEGF medications inhibit the growth of VEGF proteins, which in the eye promote growth of abnormal blood vessels underneath the retina. These medications are introduced with intravitreal injections that are administered over a period of time.

Focal laser is a high-intensity light that seals off and destroys leaky blood vessels. This can help block or delay the growth of new blood vessels which could otherwise further damage vision.

Corticosteroids are drugs that are injected into the eyes to help improve vision by decreasing the swelling of DME.

Low vision aids

There are low vision aids that are commercially available to help anyone living with a reduced visual field. Magnifying glasses, high-intensity lamps, and large print reading materials are just a few of those that can help people with DME function more easily.

Preventing DME

In general, keeping good control of diabetes is the best way to avoid many medical complications. Steps to prevent DME include taking good care of yourself, eating well, maintaining a healthy weight, controlling your blood sugar, blood pressure and cholesterol, and maintaining a consistent exercise program. People with diabetes should have their eyes checked annually or more often if recommended by their physician or ophthalmologist.³