Controlling diabetes to treat diabetic macular edema

Diabetic macular edema (DME) is a complication of diabetic retinopathy, damage to the blood vessels in the eye caused by diabetes. When a person has DME, blood vessels in the eye leak into the macula, a layer of light sensitive cells in the back of the eye. This causes the macula to fill with fluid and swell. This can occur in one eye or in both eyes.

A person with DME can experience a variety of vision problems, such as blurred or wavy vision, a sudden increase in floaters, double vision, and difficulty seeing colors. A person can also experience severe vision loss, especially when DME is left untreated. DME affects people with type 1 and type 2 diabetes, with a higher prevalence among people with type 1 diabetes.

What is the goal of treating DME?

In most cases, the first step in treatment will be injections of anti-VEGF medications. “VEGF” stands for vascular endothelial growth factor. This is a protein produced by multiple types of cells throughout the body. VEGF helps blood vessels maintain good structure and promotes the growth of new blood vessels—which helps keep blood flowing to parts of the body that need it, like the macula.

Excess amounts of VEGF can cause blood vessels to leak and are a major contributing factor to DME. Chronically elevated blood glucose levels are associated with the production of excess VEGF. Studies have detected higher levels of VEGF in the blood of people who have diabetic retinopathy and diabetic neuropathy (nerve damage).

Anti-VEGF medications block VEGF. When injected into the eye, these medications can help stop blood vessels from leaking. This gives the eye a chance to clear out the excess fluid that has accumulated. This is not a cure for DME, but it can stabilize vision. Some people also see an improvement in vision.

However, anti-VEGF therapy on its own is not enough to treat DME. Improving diabetes control is also an essential part of the process.

How diabetes damages the eyes

Diabetic retinopathy and diabetic macular edema occur when blood glucose levels are elevated for long periods of time, which causes damage to the blood vessels in the eye.

How this damage occurs is complex and involves multiple factors, including:

• Waste products left over from glucose metabolism that contribute to plaques that clog, stiffen, and narrow blood vessels.
• The accumulation of free radicals that cause damage to cells.
• The release of chemicals that regulate the flow of blood between blood vessels and tissues.
• The release of excess amounts of VEGF, inflammatory chemicals, and other substances that compromise the small blood vessels in the eyes.
• Other factors, including elevated blood pressure, which puts more stress on blood vessels in the eye.

By the time a person is diagnosed with DME, damage has already occurred. But improving diabetes control can prevent further damage from occurring. Better control will help a person get the most from treatment with therapies like anti-VEGF medications.

Improving diabetes control

Diabetes is a different experience for everyone, and your best source of information will always be a healthcare provider. Here are some topics to get started.

• A good place to begin is with your ABC numbers—A1C, blood pressure, and cholesterol. Know these numbers, and work with your healthcare provider to set goals for these numbers.
• If you smoke, quit. Smoking increases the risk of diabetes complications including eye problems, stroke, heart attack, amputations, and kidney disease. A healthcare provider can advise you on strategies and therapies to help you quit smoking.
• For people with diabetes who are overweight or obese, losing weight can help improve blood sugar control and reduce the risk of diabetes-related complications. Talk to your healthcare provider about strategies for losing weight, including increasing physical activity and changes to diet.
• Talk to your healthcare provider about the medications you are taking to manage diabetes, and if you need to make any adjustments. Be honest if you have concerns about a medication—for example, if you are concerned about cost or if it’s difficult to follow the dosing schedule.

In addition to helping prevent further damage to the eyes, improving diabetes control will also help reduce the risk of other diabetes-related complications, including damage to the heart, the nerves, the brain, and the kidneys.