Diabetes-Related Macular Edema (DME)
The National Eye Institute estimates that 11 million Americans have age-related macular degeneration, and about 750,000 also have diabetes-related macular edema (DME), which typically starts as diabetes-related retinopathy. What is diabetes-related macular edema? Macular edema is when your macula (the center of your retina) swells due to fluid buildup from damaged, leaky blood vessels. The macula is the part of the retina responsible for our central vision, which is needed for reading, seeing faces, and driving. The macula is also vital for the sharpness or fine detail of what we see and most of our color vision. DME is one of the most common diabetes-related eye complications and causes of vision loss. Approximately 12% of people with type 1 and 28% of people with type 2 are affected by DME.
Causes of Diabetes-Related Macular Edema
While many different conditions can cause macular edema, the most common one is diabetes-related retinopathy. In this case, the condition is called diabetes-related macular edema (DME). Years of high glucose levels can damage the macula. If you have diabetes-related retinopathy, managing your diabetes can help prevent or delay vision loss. Getting a comprehensive, dilated eye exam at least once a year is also essential. Diabetes-related eye diseases such as retinopathy, macular edema, glaucoma, or a combination of these conditions can lead to complete retinal detachment and vision loss, especially if the conditions are not detected in their early stages and carefully managed.
Aging can also cause edema or swelling of the macula, as with age-related macular degeneration or AMD. There are two types of AMD: dry and wet. The most common type is dry AMD, affecting about 8 out of 10 people with AMD. In this condition, the macula thins as it ages. Dry AMD usually progresses slowly over several years and can become wet AMD. In wet (or advanced neovascular) AMD, abnormal blood vessels in the macula leak fluid into the retina, causing fluid buildup and swelling. This damages the macula, usually causing more rapid vision loss. A person’s age (often occurs in people 50 years and older), family history, and history of high blood glucose and high blood pressure can all put a person at risk for wet AMD.
Diabetes-Related Macular Edema Symptoms
What are the symptoms of macular edema? People with DME will usually have blurry vision and vision that worsens over time. Some experience a more severe central vision loss, making reading and driving harder. Objects may appear to be wavy, especially when you are looking straight ahead. Objects can also seem different sizes if you look out of one eye and then another. Colors may appear dull or faded. Macular edema can occur in just one eye. In that case, it may take longer to notice vision changes. Like with diabetes-related retinopathy, you probably won’t notice any changes in your vision in the early stages. However, an eye doctor can spot early signs of the condition with regular retina screenings. Annual eye exams are essential to identify the problem early when treatment will be most effective. Early treatment can help reduce the swelling and prevent vision loss.
Testing for Diabetes-Related Macular Edema
How will my eye care professional check for DME? Eye care professionals can check for diabetes-related macular edema as part of a comprehensive, dilated eye exam. Eye drops will dilate your pupil to let more light into your eye. Dilation helps your eye care professional check for common eye problems, including diabetes-related retinopathy, glaucoma, and macular edema.
If macular edema is suspected, your eye care professional may do more tests to find out for sure. Tests include:
Fluorescein Angiogram
For this test, a special dye is injected into the arm. The dye travels through the bloodstream to the eye. This allows your eye care professional to see pictures of the blood vessels in your retina. A camera is used to take photos as the dye flows through the blood vessels in your retina.
Optical Coherence Tomography (OCT)
In this test, a special machine will be used to take pictures of the retina and other parts of the eye. This allows your eye care professional to look at the back of your eye so they can see how much swelling there is.
Amsler Grid
In this test, your eye care professional will check your central vision by asking you to look at a picture of a grid. If part of the grid looks wavy or dark, you may have central vision loss.
Diabetes-Related Macular Edema Treatment
If you have DME, the first step is carefully managing your diabetes to help prevent vision loss. This includes eating a healthy plant-based eating pattern, including omega-3-rich fish. We will discuss nutrition therapy as it relates to vision health in article 5. Eating meals low in fat and rich in fruits, vegetables, and whole grains can help not only your heart but also your eyes. Your eyes rely on tiny blood vessels for oxygen and nutrients, just like the heart relies on much larger blood vessels. Keeping those blood vessels healthy helps keep your eyes and your heart healthy.
Your eye care professional may also recommend one of the following treatment options:
Injections
Anti-VEGF medications such as aflibercept (Eylea), bevacizumab (Avastin), or ranibizumab (Lucentis) block the growth of abnormal blood vessels in the eye, stop fluid leaks, and slow down or even reverse macular edema. They can stop further vision loss and may even improve vision. The medicine is injected into the eye during monthly office visits. Beovu (brolucizumab, is another VEGF inhibitor, now approved to treat DME that requires less frequent injections.
Vabysmo (faricimab-svoa)
This injectable works by targeting and inhibiting two disease pathways that are thought to damage blood vessels in the eye. By stopping these blood vessels from growing, Vabysmo may decrease the risk of bleeding and fluid buildup in the eyes. This treatment reduces the frequency of required in-clinic visits and injections to the eye, improving quality of life and reducing costs.
Refillable Implant
A refillable implant is now available, which can continuously deliver anti-VEGF medicine into the eye to treat wet AMD. This provides more consistent treatment to protect vision better. Patients who have responded to at least two injections of anti-VEGF medicine may be candidates for the implant. During a one-time outpatient procedure, a retinal specialist surgically inserts the device (about the size of a grain of rice) into the eye. Patients receive a local anesthetic and a mild sedative. The implant is refilled in the ophthalmologist’s office every six months. The implant has been associated with a three-fold higher rate of infection compared with monthly injections of anti-VEGF medicine.
Eye Drops
Your eye care professional may recommend an eye drop called nonsteroidal anti-inflammatories (NSAIDs). These can help prevent or treat macular edema caused by surgery. You may be instructed to use these eye drops by themselves or along with steroid eye drops.
Laser Treatment
Certain types of laser treatment can be used to treat DME. Your eye care professional might recommend laser treatment if injections haven’t worked to treat your macular edema.
Eye Surgery
Your eye doctor may recommend a type of surgery called a vitrectomy if other treatments haven’t worked. During a vitrectomy, tiny openings are made in your eye wall to remove most of the vitreous (gel-like fluid that fills your eye) from your eye with a suction tool. Another type of surgery is to implant the refillable device (above), which makes it easier to get regular injections.
Age-Related Eye Disease Study (AREDS2) Supplements
People with certain forms of AMD may be able to slow the progression of the disease to an advanced form by taking the AREDS2 supplements. This formula developed from the AREDS—includes:
- Vitamin C (500 mg)
- Vitamin E (400 IU)
- Lutein (10 mg)
- Zeaxanthin (2 mg)
- Zinc oxide (80 mg)
- Copper oxide (2 mg)
Injections of steroids can also help with swelling in the retina. Your eye care professional usually injects these medicines into or close to your eye. Learn more about injections to treat macular edema.
It is important to talk with your ophthalmologist or eye doctor to determine if they are recommended. Some people should not take large doses of antioxidants or zinc for medical reasons. Also, keep in mind that vitamins and supplements are not a cure for eye disease and cannot restore vision that has already been lost.
Cutting-Edge Research on Diabetes-Related Macular Edema
What’s the latest research on macular edema for people with diabetes? Researchers are exploring better ways to prevent and treat macular edema, including comparing anti-VEGF drugs and studying alternatives to anti-VEGF treatment in clinical trials. Promising new research has been reported on a potential topical eye drop that would provide a less invasive treatment option if approved. Researchers also continue to study the diseases that cause macular edema, like diabetes-related retinopathy and retinal vein occlusion.
References:
Romero-Aroca P. Managing diabetic macular edema: The leading cause of diabetes blindness. World J Diabetes. 2011 Jun 15;2(6):98-104. doi: 10.4239/wjd.v2.i6.98. PMID: 21860693; PMCID: PMC3158878.
https://www.nei.nih.gov/sites/default/files/nehep-pdfs/GM_DED_drop-in%20article_2014.pdf. Accessed April 3, 2024.
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