DME vs AMD: What’s the Difference?
It’s easy to get these two chronic eye conditions confused. We asked the experts to help clear things up.by Erin L. Boyle Health Writer
Diabetic macular edema. Age-related macular degeneration. Perhaps you or someone you care about has one, but you’re not sure which one. That’s perfectly understandable—they’re both mouthfuls, and not necessarily words you’re familiar with. So what are these eye conditions and how different are they? We asked the experts to explain what these terms really mean, and it turns out, they have quite a few similarities—and a lot of differences, too. Let’s dive in to learn more about DME and AMD from experts in the field.
What Is DME?
Diabetic macular edema, commonly referred to as DME, is a complication of diabetic retinopathy (DR), the presence of abnormal blood vessels in the eye due to high glucose levels. High sugar levels weaken and damage blood vessels over time. When those compromised blood vessels are in the eye, it can spur them to leak fluid, blood or deposits into the retina, causing it to swell and distort vision. When the swelling is in the macula (or center of the retina), that’s DME. While nearly eight million Americans live with DR, just 10% of them—about 750,000—develop DME.
DME is highly treatable and today’s treatments are fortunately relatively painless. However, if left untreated, DME can lead to permanent vision loss. Since DME often has no symptoms (such as floaters in the eye or blurry vision) until it’s progressed, it’s especially important that people with diabetes get an annual eye exam. Early detection is key!
What Is AMD?
Age-related macular degeneration (AMD) is a leading cause of vision loss for people aged 50 and older. Like DME, AMD is a retinal condition that happens in the macula—drusen deposits build up in the early part of the disease, called dry AMD. As the disease progresses to wet AMD, drusen disrupts the way the eye functions, allowing new and abnormal blood vessels to grow. This causes vision distortions, blurring, and difficulty seeing objects right in front of you. If left untreated, wet AMD can progress to irreversible vision loss.
How DME and AMD Differ
A big distinction is pathology, says Abdhish R. Bhavsar, M.D., a retina specialist in Minneapolis and clinical spokesperson for the American Academy of Ophthalmology. DME occurs because of diabetes; AMD because of the aging process. In rare cases, they can occur at the same time, but typically occur for different reasons. DME doesn’t spur new blood vessel growth for instance, and AMD isn’t the result of damage from DR.
“Diabetic retinopathy is more complex than macular degeneration because there are many different forms of retinopathy that can affect the vision and can cause blindness and loss of vision if not treated,” Dr. Bhavsar says.
While both DME and AMD happen in the macula, the location isn’t exactly the same. DR/DME is more intraretinal (within the retina and the vessels of the retina), whereas AMD involves choroidal neovascularization, the medical term for blood vessels that are typically under the retina that don’t belong there, Dr. Bhavsar explains.
They differ in how they affect vision: DME/DR might not cause any symptoms until it’s advanced, which is typically a gradual central vision blurring. When AMD changes from dry to wet, the process can be quick, with distortion, blurring, and blind spots in the center of your vision, says David Eichenbaum, M.D., a retina specialist and director of research for Retina Vitreous Associates of Florida in Tampa Bay, FL.
“The most common symptom of diabetic eye disease progressing is really no symptom,” Dr. Eichenbaum says. “You don’t notice it’s getting worse, until you get gradually blurry in the center, or you get floaters from proliferation. Whereas in wet AMD, almost overnight, patients get distortion or a spot that occludes their central vision. That’s a big difference.”
Treatments are similar, but there are more treatment options for DME than AMD, Dr. Bhavsar points out, including injectable anti-vascular endothelial growth factor (anti-VEGF) drugs, focal laser, corticosteroids, and surgery. Your doctor may recommend more than one treatment, known as combined therapy. Wet AMD, in contrast, is treated only with anti-VEGF drugs, Dr. Eichenbaum says.
Age is another difference between DME and AMD. DME can happen at any age, unlike AMD, which, by its definition (“age-related”) occurs in people 50 years and older. With that difference comes unique challenges.
“The patients you’re treating with diabetic macular edema are often people of working age, anywhere from their 20’s [and above],” Dr. Eichenbaum says. “With wet age-related macular degeneration, you’re often treating people who are retired.”
If you’re younger and afflicted with DME, you might have a challenging time, but take heart: Once vision has stabilized and the edema reduced, treatments can likely taper. With wet AMD, however, anti-VEGF treatment is often for life, as you receive injections to stave off vision loss and progression.
Another difference between the two? The amount of control you have over your condition. “Patients with diabetes are in a lot better control of their disease process,” Dr. Eichenbaum explains. Among the options available to them to help stop progression of their DME:
Starting a diabetes-healthy diet
Trying a new diabetic medicine or beginning insulin
One key risk factor someone with AMD can do is stop smoking, Dr. Eichenbaum says. Chemicals in cigarettes can damage the retina when they travel through the bloodstream.
What Are the Similarities?
Both conditions involve the macula—as their names suggest and both affect your central vision. You’ll notice those visual disturbances when looking straight ahead most commonly. Both eye conditions are treated, safely and effectively, with anti-VEGF injections into the eye.
“This treatment blocks vascular endothelial growth factor, which helps to slow down leakage in diabetic macular edema and also slows bad blood vessel growth in wet age-related macular degeneration,” Dr. Bhavsar explains.
Whichever condition you have, you’ll see an ophthalmologist (or eye doctor) who specializes in conditions that impact the retina. It’s possible to have both DME and AMD at the same time, if you’re 50 or older and have diabetes with extended high blood sugar levels. Typically, one anti-VEGF injection can be placed in the same part of the eye to treat both at once.
“We do the injections the same, no matter which disease we’re treating,” Dr. Bhavsar says. “Once we put the medicine into the vitreous cavity, it floats to the back of the eye and blocks receptors independent of which disease process is causing it.”
Whether you have DME or AMD, you should stay in regular contact with your eye doctor. See them on an annual basis, even if your diabetic eye disease is well-controlled, and definitely as often as your doctor recommends if you have wet AMD.
- Diabetic Retinopathy and DME: National Eye Institute. (2019). “Diabetic Retinopathy.” nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/diabetic-retinopathy
- Stages of DME: American Academy of Ophthalmology. (2020). “What Is Diabetic Retinopathy?” aao.org/eye-health/diseases/what-is-diabetic-retinopathy
- About AMD: National Eye Institute. (2020). “Age-Related Macular Degeneration.” nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/age-related-macular-degeneration
- Differences, Similarities: Archives of Medical Science. (2016). “Diabetic macular edema, retinopathy and age-related macular degeneration as inflammatory conditions.” ncbi.nlm.nih.gov/pmc/articles/PMC5016593/