Diabetic macular edema is a complication that affects some people with diabetes. It’s characterized by fluid build-up in the macula — the part of the eye that helps you achieve sharp, straight-ahead vision, according to the National Eye Institute.

When fluid leaks from nearby blood vessels, the macula swells and thickens, which alters vision, per to Mayo Clinic

If you have diabetic macular edema, you may experience trouble seeing or even blindness.

Diabetic macular edema can affect people with both type 1 and type 2 diabetes, notes Prevent Blindness.

It’s strongly related to uncontrolled blood sugar levels and other health conditions, like high blood pressure and high cholesterol.

The outlook is better when this condition is caught early. With the right treatment, vision loss can usually be stopped, and sometimes, reversed, according to the American Diabetes Association.

Causes and Risk Factors of Diabetic Macular Edema

Diabetic macular edema is essentially a result of another diabetes complication, called diabetic retinopathy.

Diabetic retinopathy happens when there’s damage to small blood vessels in the retina — a thin layer of tissue that lines the back of your eye. This damage is usually due to blood sugar levels being consistently too high. Other issues, like high blood pressure and high cholesterol, can also lead to blood vessel damage.

If retinopathy isn’t treated, tiny bulges in the vessel walls can leak fluid into the retina.

The leakage may cause the macula, which is located in the center of the retina, to swell. This swelling, or “edema,” is known as macular edema.

Risk Factors for Diabetic Macular Edema

Some risk factors for diabetic macular edema include:

Poor blood sugar control over a long period of time
High blood pressure
Kidney disease
Fluid retention
High cholesterol
Having diabetes for a long time
Obesity
Sleep apnea
Cataract surgery

Additionally, people with type 1 diabetes are more at risk than those with type 2. After having diabetes for 20 years, nearly all individuals with type 1 will develop some form of diabetic retinopathy, while about 60 percent with type 2 will experience this complication.

Women who develop diabetes during pregnancy (gestational diabetes) are also at risk for diabetic macular edema.

Overall, men are more likely than women to develop diabetic macular edema, according an analysis published in April 2019 in Optometry and Vision Science.

How Is Diabetic Macular Edema Diagnosed?

To diagnose diabetic macular edema, your eye doctor will likely first perform a comprehensive vision exam. They will need to widen (dilate) your pupils to better see your retina and look for signs of damage, according to the American Academy of Ophthalmology.

Your doctor might also perform or suggest the following tests:

Optical Coherence Tomography (OCT) With OCT, a special machine scans the retina and provides detailed views of its thickness. It can help measure the amount of swelling in the macula.
Fluorescein Angiography A yellow dye is injected into a vein and moves through your blood vessels. Doctors use a special camera to capture images of the retina as the dye travels through its blood vessels. It can help your doctor determine the amount of damage to the macula.
Visual Acuity Test This common way to assess vision loss involves using a standardized chart with rows of letters. You’re asked to cover one eye and read the smallest line of letters you can see.
Amsler Grid This method is used to test your central vision. You basically look at a grid and report if any parts are missing, distorted, or dark.

Prognosis of Diabetic Macular Edema

There’s no cure for diabetic macular edema, but treatments can help slow down the progression and prevent further damage.

In some cases, diabetic macular edema is reversible if it’s caught in the early stages. But, if it goes untreated for a long time, the condition could cause permanent changes in the retina, per past research.

In one large study of people with diabetes, 50 percent with diabetic macular edema had visual impairment compared with sixteen percent without macular edema. About 20 percent who had diabetic macular edema had blindness compared with 4 percent of those with diabetes without the condition.

Duration of Diabetic Macular Edema

Though many treatment options are available, diabetic macular edema is still considered a chronic condition that requires long-term follow-up care, according to an article published in October 2015 in Federal Practitioner.

Some people will experience a complete response to a single therapy, while others may need many treatments over a longer period of time. It’s important to attend all your medical appointments, so your doctor can keep a close watch on your condition.

Treatment and Medication Options for Diabetic Macular Edema

Treatments for diabetic macular edema will depend on your overall health, how severe the condition is, and other factors. It’s important to remember that habits like good blood sugar control and a healthy lifestyle are essential for a successful treatment outcome.

Medications Options

Some medicines used to treat diabetic macular edema include:

Anti-Vascular Endothelial Growth Factor (Anti-VEGF) Drugs These medicines are given as an injection into the eye. They block the development of new, abnormal blood vessels and help control leakage from damaged blood vessels. Typically, several injections are needed.
Research published in April 2018 in the Canadian Journal of Diabetes shows that this form of therapy can improve vision.
According to the National Eye Institute, anti-VEGF medicines are currently considered the standard of care for macular edema.
Serious risks are rare but can include infection, inflammation of the eye, bleeding, or retinal detachment, notes the American Society of Retina Specialists.
Corticosteroids Steroids can reduce inflammation in the eye. They’re usually given as an injection into the eye or as an injectable eye implant that releases the drug over time.
Steroids may increase your risk of developing glaucoma or cataracts, so you should talk to your doctor about the pros and cons.

Laser Treatment

A procedure called focal laser is used to seal up leaking blood vessels. It can slow or stop the growth of new blood vessels that could cause damage. The goal of this laser is to protect the vision you have and prevent future vision loss. One risk of focal laser is that it can leave permanent blind spots in your vision. You should talk to your doctor about this potential complication.

Surgery

Your doctor may recommend surgery if your condition is caused by vitreous (the gel-like fluid that fills your eye) pulling on the macula. In this case, a procedure called a vitrectomy is used to restore the macula to its normal shape.

Prevention of Diabetic Macular Edema

You can help prevent diabetic macular edema by:

Maintaining good blood sugar control
Keeping blood pressure and cholesterol levels in check
Receiving a comprehensive eye exam at least once a year
Following a healthy lifestyle that includes regular exercise and a nutritious diet

Regular eye exams and screenings are extremely important for people at risk for diabetic macular edema because symptoms don’t always show up.

Pregnant women with diabetes should have an eye exam as soon as possible to spot any potential problems.

Research and Statistics: Who Has Diabetic Macular Edema?

According to the National Eye Institute, about 750,000 Americans have diabetic macular edema.

Research shows that up to 10 percent of people with diabetes may develop the complication.

When it comes to worldwide statistics, the International Diabetes Federation (IDF) estimates that more than 28 million people are currently affected by diabetic macular edema.

Diabetic macular edema is the leading cause of vision loss and legal blindness in people with diabetes, per past research.

Black Americans and Diabetic Macular Edema

Research suggests that Black Americans are disproportionately affected by diabetes and diabetic macular edema.

According to the U.S. Department of Health and Human Services Office of Minority Health, African Americans are 60 percent more likely to be diagnosed with diabetes compared with white, non-Hispanic adults.

Recent research has also shown that African Americans are 3 times more likely to develop diabetic macular edema, per the National Eye Institute.

What’s more, a study published in October 2020 the American Journal of Ophthalmology revealed that Black Americans had poorer treatment outcomes.

Black American patients with diabetic macular edema who received the anti-VEGF drug Avastin (bevacizumab) were significantly less likely to show improvement in vision than white patients.

Specifically, when receiving three injections, 33.82 percent of Black Americans compared with 54.76 percent of Hispanics and 58.54 percent of whites Americans experienced visual acuity improvements, as noted by an article about the study published in November 2020 in Health City.

Researchers say these results highlight the need to include more racial diversity in clinical trials. They want to better understand why these treatment disparities exist and identify therapies that could help Black American patients.

Resources for Diabetic Macular Edema

If you or a loved one have been diagnosed with diabetic macular edema, you probably have a lot of questions and concerns. Luckily, there are many resources to help you manage this condition.

American Academy of Ophthalmology

The American Academy of Ophthalmology is the world’s largest association of eye physicians and surgeons, consisting of 32,000 medical doctors. Their site offers credible information about various conditions affecting the eye, including diabetic macular edema.

NIH: National Eye Institute

The NIH’s National Eye Institute provides detailed educational materials for different types of eye diseases and conditions. From fact sheets to webinars, their resources can help you learn more about diabetic eye diseases and how to lower your risk of vision loss.

American Diabetes Association (ADA)

The ADA’s mission is to prevent and cure diabetes and improve the lives of all people affected by the disease. Their site offers useful information about diseases that affect vision as well as stories from patients who are living with diabetes-related eye conditions.

PreventBlindness.org

Prevent Blindness is an organization with a mission that echoes its name: to prevent blindness and preserve sight. We especially like their Resources for Low Vision page, which provides links to financial assistance sites, doctor searches, assistive technology products, and more.

VisionAware

VisionAware is a free informational service for people affected by vision loss. In addition to providing personal stories, the organization offers a feature that lets you search for local support groups in your area.

DiabetesNet

This site offers an array of diabetes products available for purchase. Some popular items include cookbooks, glucose monitors, pump accessories, and more.

KNFB Reader App

This handy app converts text into speech or Braile instantly to give people with vision problems access to print. It also allows users to easily send and share documents.

Be My Eyes App

This free application connects people with vision problems with sighted volunteers who can provide assistance via a live video call. It’s now available in 180-plus different languages in more than 150 countries.