What is diabetic macular edema? It is swelling in the macula, the part of the retina you need for reading, driving, and seeing faces. The National Eye Institute (NEI) says it happens when blood vessels in the retina leak fluid into the macula, which causes blurry vision, and that it is called diabetic macular edema (DME) when diabetic retinopathy is the cause. The American Diabetes Association (ADA) says anyone with DME of any level should be referred promptly to an ophthalmologist experienced in managing diabetic retinopathy.
Key takeaways
- DME is swelling in the center of the retina. NEI says blurry vision and vision that gets worse over time are its main symptoms.
- The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says DME usually develops in people who already have other signs of diabetic retinopathy.
- A dilated eye exam can find it, and imaging called OCT shows how much swelling there is.
- Anti-VEGF injections are the first-line treatment for most eyes with center-involving DME that affects vision, according to the ADA. Close monitoring is an option when vision is still good.
- Not all macular edema is DME, so an eye doctor needs to find the cause.
Diabetic Macular Edema: The Short Answer
- It is a retina problem in the center of the eye. NIDDK says diabetes can lead to swelling in the macula, and over time this disease can destroy the sharp vision in this part of the eye.
- It builds on retinopathy. NIDDK says it usually develops in people who already have other signs of diabetic retinopathy.
- It can be mild or severe. NEI says some people have mild blurry vision and others have severe central vision loss.
- Eye doctors can find it and treat it. Treatments include injections, laser, and sometimes surgery.
- It needs specialist follow-up. The ADA calls for prompt referral for any level of DME.
What the Macula Does and What Goes Wrong
NIDDK describes the macula as the part of the retina you need for reading, driving, and seeing faces. The retina is the light-sensitive layer at the back of the eye.
High blood sugar over time can damage the tiny blood vessels that supply the retina. NEI says these changes can lead to blocked vessels that leak fluid or bleed. When the leaking vessels are near the macula, fluid collects and the macula swells, which blurs central vision.
How Common Is DME?
Two commonly quoted figures count different groups of people, so they are not in conflict.
| Source | What it says |
|---|---|
| NEI | Over time, about 1 in 15 people with diabetes will develop DME |
| Centers for Disease Control and Prevention (CDC) | About half of people with diabetic retinopathy develop macular edema, and it is the most common cause of blindness in people with diabetic retinopathy |
| NIDDK | Macular edema usually develops in people who already have other signs of diabetic retinopathy |
NEI's figure counts everyone with diabetes. The CDC's figure counts only people who already have retinopathy. Neither figure predicts what will happen to you.
Diabetic Retinopathy vs Diabetic Macular Edema
| Diabetic retinopathy | Diabetic macular edema | |
|---|---|---|
| What it is | Damage to the blood vessels in the retina from diabetes | Swelling in the macula when retinal vessels leak fluid |
| Where | Anywhere in the retina | The macula, which gives sharp central vision |
| Relationship | Can exist without DME | Usually develops in people who already have retinopathy (NIDDK) |
| Early signs | Often none (NEI, MedlinePlus) | Blurry or wavy central vision, dull colors (NEI) |
| How it is found | Dilated eye exam | Dilated eye exam, often with OCT imaging |
Our guide on whether diabetic retinopathy is reversible covers the broader retinopathy picture.
Symptoms of DME
NEI says blurry vision and vision that gets worse over time are the main symptoms of macular edema. You may also notice:
- Objects that look wavy, especially when you look straight ahead
- Objects that look different sizes when you look out of one eye and then the other
- Colors that look dull or faded
If DME is in only one eye, NEI says it may take longer to notice changes. That is one reason the dilated exam matters even when you feel your vision is fine. Blur has several possible causes in diabetes, and our guide to blurry vision and diabetes shows how short-term glucose blur differs from blur that needs an eye doctor.
Other Causes of Macular Edema
NEI says diabetic retinopathy is the most common cause of macular edema, but there are others, including wet age-related macular degeneration, retinitis pigmentosa, uveitis, blocked veins in the retina, eye surgery such as cataract surgery, and certain medicines, including some used for glaucoma. Because the cause decides the care, an eye doctor needs to find it, and you should ask before changing any eye medicine. Our guides explain cataracts and diabetes and glaucoma and diabetes.
How Eye Doctors Check for DME
NEI says eye doctors check for macular edema as part of a dilated eye exam, which is simple and painless. If your doctor suspects it, further tests may include:
- Optical coherence tomography (OCT). Pictures of the retina that show how much swelling there is.
- Fluorescein angiogram. A dye is injected into your arm, and a camera photographs the blood vessels in your retina as the dye flows through them.
- Amsler grid. A grid test that shows whether you have lost any central vision. Wavy or dark parts of the grid can mean central vision loss.
Our guide to how often diabetics should get an eye exam explains the schedule and what a dilated exam involves.
How Eye Doctors Approach DME Treatment
Your eye doctor decides the plan. This is the general picture from the ADA, NEI, and NIDDK.
- Anti-VEGF injections. The ADA says these are first-line for most eyes with DME that involves the center of the macula and impairs vision. NIDDK says injections are given in the office after the eye is numbed, with several treatments in the first few months and fewer after the first round.
- Laser or steroid injections. The ADA says laser and steroid injections are reasonable for DME that persists despite anti-VEGF, or for eyes that are not candidates for anti-VEGF, for example because of pregnancy. AAO's EyeNet notes that steroid treatment carries risks including earlier cataract formation and raised eye pressure, which is why your doctor may keep an eye on both. See cataracts and glaucoma.
- Surgery. NEI says doctors may recommend a vitrectomy if other treatments have not worked.
- Monitoring first. In a trial reported by NEI, people with DME involving the center of the macula but good vision (20/25 or better) were assigned to an anti-VEGF medicine, laser, or close observation. After two years, 16% of the injection group, 17% of the laser group, and 19% of the observation group had lost one or more lines on the eye chart, and NEI says these rates did not differ among the groups. When vision dropped, 25% of the laser group and 34% of the observation group went on to need injections. NEI says watching closely can be reasonable for people with DME and good vision.
What treatment can and cannot restore is covered in our guide on whether diabetic retinopathy is reversible. NEI says treatment can help reduce the swelling and prevent vision loss.
What Else Your Care Team Looks At
NEI says that if you have DME, managing your diabetes can help prevent vision loss, and that people with retinopathy should get a dilated exam at least once a year. The ADA's Standards of Care in Diabetes—2026 add that lowering blood pressure reduces retinopathy progression and that sight-threatening retinopathy, including DME, is reduced with statin use. The ADA also says a class of diabetes medicines called thiazolidinediones might be associated with developing or worsening DME, although the evidence is conflicting. These notes are for conversations with your prescriber, not a reason to start or stop any medicine yourself.
For the wider picture, see how diabetes affects the eyes.
When to Get Help Right Away
AAO says the sooner you notice a symptom, the more likely treatment will help, so call your eye doctor if you notice new blur, wavy lines, or dull colors. NIDDK says to call a doctor right away for flashes of light, many more floaters than usual, or a curtain-like shadow over your vision, which can signal a detached retina.
Questions to Ask Your Care Team
- Is there any sign of retinopathy or swelling in my macula?
- Did you use OCT imaging, and what did it show?
- How often should I be checked?
- If I need treatment, what are my options and what monitoring follows?
- Do any medicines I take affect my eyes or my blood sugar?
Frequently Asked Questions
What is diabetic macular edema?
It is swelling in the macula, the center of the retina that gives sharp central vision. NEI says it happens when blood vessels in the retina leak fluid into the macula, and that it is called diabetic macular edema when diabetic retinopathy is the cause.
Is diabetic macular edema the same as diabetic retinopathy?
No. Diabetic retinopathy is damage to the blood vessels in the retina, while DME is swelling in the macula. NIDDK says macular edema usually develops in people who already have other signs of diabetic retinopathy.
What are the first symptoms of diabetic macular edema?
NEI says blurry vision and vision that gets worse over time are the main symptoms. Objects may look wavy or different sizes in each eye, and colors may look dull. If only one eye is affected, changes may take longer to notice.
How is diabetic macular edema diagnosed?
Through a dilated eye exam. NEI says that if your doctor suspects macular edema, tests can include OCT imaging, a fluorescein angiogram, and an Amsler grid.
Does diabetic macular edema always need treatment right away?
Not always. The ADA calls for prompt referral for any level of DME and says anti-VEGF injections are first-line for most eyes where the center of the macula is involved and vision is affected. NEI reports that when vision is good, closely watching the eye is a reasonable option.
Can diabetic macular edema be reversed?
NEI says treatment can help reduce the swelling and prevent vision loss, and that anti-VEGF medicines can slow down or reverse macular edema. How much vision returns depends on the eye, which is a question for your eye doctor.
References
- National Eye Institute. "Macular Edema." Accessed October 2026.
- National Eye Institute. "Diabetic Retinopathy." Accessed October 2026.
- National Institute of Diabetes and Digestive and Kidney Diseases. "Diabetic Eye Disease." Accessed October 2026.
- Centers for Disease Control and Prevention. "Vision Loss and Diabetes." Accessed October 2026.
- American Academy of Ophthalmology. "Diabetic Macular Edema: Diagnosis and Management." EyeNet Magazine. May 2021. Accessed October 2026.
- American Academy of Ophthalmology. "How Diabetes Affects Your Eye Care." Accessed October 2026.
- National Eye Institute. "Watchful Waiting Reasonable for Patients With Diabetic Macular Edema and Good Vision." Accessed October 2026.
- Baker CW, Glassman AR, Beaulieu WT, et al. "Effect of Initial Management With Aflibercept vs Laser Photocoagulation vs Observation on Vision Loss Among Patients With Diabetic Macular Edema Involving the Center of the Macula and Good Visual Acuity: A Randomized Clinical Trial." JAMA. 2019;321(19):1880–1894.
- MedlinePlus. "Diabetic Eye Problems." Accessed October 2026.
- American Diabetes Association Professional Practice Committee for Diabetes. "12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes—2026." Diabetes Care. 2026;49(Suppl. 1):S261–S276. Accessed October 2026.
Next Steps
If you have noticed wavy lines, uneven sizes between your eyes, or duller colors, write down when they started and bring the notes to an eye doctor. If you have retinopathy already, ask when your next dilated exam should be.
For adults with type 2 diabetes or prediabetes who want lifestyle education alongside clinical care, the Done With Diabetes™ program, a type 2 diabetes protocol, organizes daily learning about meals, movement, sleep, and stress. It does not diagnose or treat eye conditions or diabetes, interpret test results, change medicines, or replace your care team or your eye doctor.