Diabetic Retinal Oedema

Diabetes-Related Macular Edema, Diabetic Macular Edema, DME, Diabetic Macular Oedema

Diabetic retinal oedema is a serious eye condition that can affect people with diabetes, where fluid builds up in the macula at the center of the retina, potentially leading to vision loss. With early detection and proper treatment, progression can be slowed or even reversed.

Table of contents

• What is diabetic retinal oedema?
• How common is the condition?
• Associated anatomy
• How diabetes affects your eyes
• What are the symptoms?
• What causes diabetic retinal oedema?
• What are the risk factors?
• How is it diagnosed?
• Treatment options
• Lifestyle changes to manage the condition
• Preventing worsening of the condition
• Living with diabetic retinal oedema

What is diabetic retinal oedema?

Diabetic retinal oedema, also known as diabetes-related macular edema or DME, is swelling in the macula, the central part of the retina (the light-sensing tissue at the back of your eye). The macula is responsible for your sharp, central vision that allows you to see fine details, read, drive, and recognize faces^[1].

When you have diabetic retinal oedema, fluid leaks from damaged blood vessels in the retina and builds up in the macula, causing it to swell and thicken. This swelling may be accompanied by other complications such as hemorrhages, hard exudates, and cotton wool spots in the eye^[1].

The condition is a complication of diabetic retinopathy, which is damage to the blood vessels in the retina caused by high blood sugar levels over time^[3][6].

• Retina
• Macula
• Blood vessels of the eye

How common is the condition?

Diabetic retinal oedema is quite common among people with diabetes. About 1 in 14 people with diabetes develop this condition^[1]. Other sources indicate that approximately 10% of people with diabetes develop DME^[9][18].

DME is the most common cause of sight loss in people with diabetes^[3][6]. In the United States, more than 37 million adults currently have diabetes^[1].

How diabetes affects your eyes

People with diabetes are at risk of damage to their eyesight. To work properly, the eye needs a constant supply of blood. When control of blood sugar and insulin levels in the body is poor, the blood vessels of the eye become damaged. The blood vessels of the retina are particularly prone to leaking, and a condition known as diabetic retinopathy can develop^[3].

High blood sugar levels cause damage to the tiny blood vessels at the back inner wall of the eye. These damaged vessels become weak and form small bulges called microaneurysms. These bulges leak fluid and blood into the retina^[2].

There are two types of diabetic retinopathy. In non-proliferative diabetic retinopathy, blood vessels become weak and form pouches that leak. If you begin to grow new blood vessels in your eyes that don’t belong there, you have proliferative diabetic retinopathy. These new blood vessels aren’t as strong as they should be, so they also leak and allow blood to build up in your macula and retina^[1].

What are the symptoms?

In the early stages of diabetic retinal oedema, a person may not notice any effect on their vision. Damage to the retina occurs over many years. It may affect the entire retina, but when the damage causes only small bulges in the blood vessels of the retina, eyesight remains good^[3].

However, when the blood vessels in or close to the macula become damaged, or there is sudden bleeding or fluid leaking into the macula, then sight can worsen dramatically. The signs and symptoms of diabetic retinal oedema may include^[1][3]:

• Blurry vision or double vision
• Floaters (spots or dark strings floating in your sight)
• Difficulty seeing colors, or colors appearing faded
• Dark spots like a smudge on glasses or gaps in your vision, especially first thing in the morning
• Straight lines such as door frames and lamp posts appearing distorted or bent
• Difficulty seeing when there’s a glare or bright light
• Difficulty reading
• Seeing an object as being a different size when you look at it with only one eye and then the other
• Objects in front of you might change shape, size, or color, or seem to move or disappear

If you notice a sudden change in your vision, contact your optometrist or hospital eye specialist urgently^[3].

What causes diabetic retinal oedema?

Diabetic retinal oedema happens when high blood sugar levels affect the blood vessels in your eyes. Your blood vessels leak, which causes fluid to build up and thicken your retina^[1].

Over time, too much sugar in your blood causes damage to the tiny blood vessels that nourish the retina, or blocks those vessels completely^[2]. The fluid leaking from these damaged vessels can cause swelling in the macula^[2].

When you have DME, your body makes too much of a protein called VEGF (vascular endothelial growth factor). This causes blood vessels to grow too quickly, so they’re weak and leak blood and fluid into your retina and macula^[12].

What are the risk factors?

Anyone with diabetes is at risk for diabetic retinal oedema. The condition is a leading cause of vision impairment among people with diabetes, particularly those who have had diabetes for many years^[12].

The longer you have diabetes, the greater your chance of developing sight loss through DME. About 90% of people with type 1 diabetes will have some degree of retinopathy after 10 years. For people with type 2 diabetes, the chance of developing some degree of retinopathy increases over time^[3].

Other factors that put patients at risk for diabetic retinal oedema include^[12][22]:

• Poor blood sugar control
• High blood pressure
• High cholesterol levels
• Prolonged duration of diabetes
• Smoking

How is it diagnosed?

You can’t see swelling in your retina yourself, but your eye care specialist can see this when they do a thorough eye examination. This is one reason that you need to have regular eye exams. Following an eye exam schedule is especially important if you have diabetes^[1].

People with diabetes should reduce their risk of vision loss by attending their annual diabetic eye screening appointment^[3]. If you have diabetes, a yearly dilated eye exam with an eye care professional is recommended, even if your vision seems fine^[7].

In addition to the eye exam, which includes a slit lamp exam, your provider may use the following tests to diagnose and monitor DME^[1][22]:

• Optical coherence tomography (OCT): This imaging test can measure the thickness of your retina and optic nerve. It provides cross-sectional images of the retina showing the anatomy and thickness, helping determine how much fluid has leaked into retinal tissue
• Fluorescein angiography: This imaging test shows the blood vessels in your retina. After your eyes are dilated, a dye is injected into a vein in your arm. Then pictures are taken as the dye circulates through blood vessels in your eyes. The pictures can pinpoint blood vessels that are closed, broken, or leaking
• Amsler grid: This test uses a grid of horizontal and vertical lines in a visual field test
• Visual acuity test: To measure your vision at a variety of distances

Treatment options

Treatment options for DME have improved in recent years. In fact, some newer medications work well enough to reverse the damage in some cases^[1]. Treatment depends largely on the type and severity of diabetic retinal oedema you have. Treatment is aimed at slowing or stopping the condition from getting worse^[10].

Anti-VEGF injections

One form of treatment blocks vascular endothelial growth factor (VEGF), a protein that helps new blood vessels grow. Anti-VEGF injections are administered directly into your eye to reduce swelling. They help stabilize blood vessels and prevent new ones from growing^[1][12].

The main anti-VEGF medicines used in DME include^[12]:

• Aflibercept (Eylea)
• Bevacizumab (Avastin)
• Brolucizumab-dbll (Beovu)
• Ranibizumab (Lucentis)
• Faricimab-svoa (Vabysmo) – this can inhibit both VEGF and another protein called Ang-2

Your doctor uses a thin needle to place the medicine in the center of your eye. You’ll get numbing drops before the injection so you won’t feel it. Most people need one injection a month for the first 4-6 months. After that, you’ll get fewer and fewer over the next several years^[12].

Corticosteroid injections or implants

Steroids that manage inflammation are another form of treatment that’s applied to your eyes. You can get steroids in an injection or with a tiny implant in your eye. The implant releases small doses of medicine slowly, so you won’t need a series of injections. Your doctor places it in your eye with a special device. The implant dissolves over time, so you don’t need to have it taken out^[1][12].

Steroids usually don’t work as well as anti-VEGF injections, and they can cause other eye problems like cataracts and glaucoma. So they won’t be the first treatment your doctor tries^[12].

Laser treatment

Lasers can seal blood vessels in your retina to help slow leaking and bring down swelling. This is called focal-grid macular laser surgery. If you have DME in both eyes, your doctor will treat one eye at a time, with a few weeks in between. Usually you need just one treatment for each eye^[12].

Your doctor might try a laser along with anti-VEGF injections if the injections alone aren’t helping^[12].

Managing blood sugar and blood pressure

In addition to specific eye treatments, your provider will work with you to manage your blood sugar levels and your blood pressure. This process might involve other types of medications^[1].

Lifestyle changes to manage the condition

While medical treatments are important, lifestyle changes may be essential to avoiding ongoing medical treatments and actually stabilizing your vision. “We do have a lot of treatments for diabetic retinopathy and diabetic macular edema, and all of those have a temporary effect,” explains one ophthalmologist. “They don’t solve the issue until we control blood sugar.”^[17]

Control your blood sugar levels

Keeping your blood sugar levels within a healthy range is crucial for managing diabetic retinal oedema. High blood sugar levels can damage the blood vessels in the retina, leading to vision problems. Follow your healthcare provider’s advice for managing your diabetes, including diet, exercise, and medication^[21].

Good blood sugar control can slow DME and may even allow you to avoid getting started on the series of eye injections used to treat the condition^[19].

Monitor your blood pressure and cholesterol

High blood pressure and high cholesterol levels can contribute to the progression of diabetic retinal oedema. Monitor your blood pressure and cholesterol levels regularly and take steps to keep them under control^[21].

When you have diabetes, you’re more likely to have high blood pressure, which can worsen your DME. Lowering your blood pressure can reduce your chances of further illness^[18].

Maintain a healthy diet

Eating a balanced diet rich in fruits, vegetables, whole grains, and lean proteins can help manage diabetes and support eye health. Avoid foods high in sugar, saturated fats, and processed foods^[21].

A healthy and balanced diet helps keep your blood pressure and blood sugar in check. Your doctor may suggest the “plate method” to illustrate which foods to eat and in what amount^[18].

Exercise regularly

Regular physical activity can help control blood sugar levels, lower blood pressure, and improve cholesterol levels. Aim for at least 150 minutes of moderate-intensity exercise per week^[21][18].

Exercise is essential to your eye health. It can slow DME. Studies suggest there’s more blood flow to the tissue in your eye’s retina after a workout^[18].

Quit smoking

Smoking can worsen diabetic retinal oedema and increase the risk of other complications. The nicotine in cigarettes and other products may worsen your diabetes and eventually cause you to have eye problems, including blindness^[18][21].

Manage stress

Stress can affect your blood sugar levels and overall health. Find healthy ways to manage stress, such as exercise, meditation, or talking to a therapist^[21].

Preventing worsening of the condition

The proper treatment of diabetes is the best way to prevent vision loss^[7]. If you have diabetes, make eye health a priority and schedule regular eye exams to monitor for any changes. Early detection and treatment are key to preventing vision loss from diabetic retinal oedema^[21].

A serious complication of untreated diabetes-related macular edema is vision loss^[1]. Persistent edema of the retina around the macula causes damage to the neural cells, resulting in diabetic neuropathy of the retina and a reduction in vision quality. Neuronal cell death and axonal degeneration are irreversible, and their development can result in permanent visual loss. Treating the edema before these changes occur is necessary for neuroprotection and maintenance of good vision^[9].

Living with diabetic retinal oedema

The condition is painless, and although macular oedema affects central vision, peripheral vision is not affected. However, other forms of diabetic retinopathy may affect your wider vision^[3].

Get connected to the right healthcare providers

Because diabetes can impact your body in so many different ways, it’s important that your health is monitored by a team of specialists. Your primary care provider is the team captain. Having a good relationship with them is key because they’ll make sure you’re getting your annual diabetes-related exams^[19].

In addition to primary care providers and ophthalmologists, many people with diabetes see specialists like endocrinologists, certified diabetes care and education specialists, low-vision specialists, nutritionists or dietitians, cardiologists, podiatrists, dentists, and urologists^[19].

Low vision aids and rehabilitation

Having the right tools may help you adjust to your vision changes. Low vision aids can help you live independently and do things like watch TV and read. Examples include^[16]:

• Large-print newspapers, magazines, books, and medication labels
• Magnifying glasses, lenses, screens, and stands
• High intensity or extra bright reading lamps
• Telescopic lenses for seeing far away
• E-readers, computers, and tablets that let you enlarge the font size

Certain medical professionals offer low vision rehabilitation for DME. These professionals may include ophthalmologists, occupational therapists, or low vision specialists. During low vision rehabilitation, a healthcare professional will assess current eye function and then recommend strategies for maximizing the remaining vision. Research has shown that low vision rehabilitation can help people with DME regain a sense of independence^[15].

Organization tips

Individuals with DME may find it challenging to navigate familiar work or home environments. Organizing these environments can simplify this navigation as vision changes. A few tips for organizing the home and workspaces include^[15]:

• Labeling food or drawers with large-print labels
• Using safety pins to organize clothing by color
• Keeping matched socks together with a sock lock before washing and drying
• Marking preferred stovetop settings with puff paint or silicone caulk