A Comprehensive Guide to Diabetic Macular Oedema (DME)

Diabetic Macular Oedema (DME) is a condition where the macula (the central part of the retina) becomes swollen. The macula is the part of your eye that helps you see fine details like words on a page of newspaper/books or hands on a clock etc.

DME is a leading cause of vision loss among people today. However, early detection and treatment may reduce or prevent the condition.

What causes diabetes macular edema

Diabetic macular oedema (DME) is a part of diabetic retinopathy, the process where changes occur in the retina due to uncontrolled diabetes. occurs due to the leakage of fluid from fragile blood vessels leading to the accumulation of fluids, lipids and proteins inside the layers of the retina. This build-up of small fluid-filled spaces in the retina may be clearly seen through an eye scan called Optical coherence tomography (OCT). This condition is caused because of: 

1. Poor blood flow in the retina

When diabetes isn’t controlled well, the tiny blood vessels in the retina can become blocked or vanish. This limits the flow of blood (retinal ischaemia). This results in creation of a substance known as VEGF that stimulates the development of new blood vessels (proliferative diabetic retinopathy) and makes existing ones leak more easily. This extra leakage allows the accumulation of more fluid in the macula, causing swelling. 

2. Eye inflammation

People with long-term diabetes are more likely to build up free radicals and advanced glycation end products. This increases the release of chemicals responsible for causing inflammation, such as IL-1b and IL-6 in the body. Further, inflammation damages the pericytes (supporting cells around the blood vessels) and weakens the vessel walls, making them more likely to leak fluid and fatty deposits, which is a sign of DME.

3. High blood pressure (hypertension)

When blood pressure is consistently high, it puts extra strain on the delicate blood vessels of the retina. Over time, this pressure damages vessel walls and makes them more likely to leak. For people with diabetes, uncontrolled hypertension significantly raises the risk of DME,

4. Cataract surgery

People with diabetes, especially those who already have diabetic retinopathy, may develop DME after cataract surgery. The risk is highest within the first three to six months after the operation, as surgery can cause temporary inflammation in the eye that leads to fluid leakage in the macula.

5. Hyperglycaemia

Poorly controlled blood sugar is a direct cause of DME, as it damages blood vessels and increases leakage. Research shows that intensive glucose control can lower the risk of DME by almost 50%. However, even after sugar levels are brought under control, the damage caused earlier (called the “legacy effect”) may continue to affect the blood vessels.

6. Obesity

Excess body weight is linked to inflammation and poor blood circulation, both of which affect the health of retinal vessels. Obesity also increases the risk of other conditions like high blood pressure and high cholesterol, which together make DME more likely. Maintaining a healthy weight can therefore reduce the chances of developing this eye condition.

What are the symptoms of DME?

Following are some signs and symptoms of DME that you may notice: 

• Blurry vision, wavy or double vision
• Eye floaters
• Colours appearing dull, faded or washed out
• Difficulty in reading
• Dark spots (scotomas)
• Difficulty seeing objects clearly from different angles & distances

If you experience any of these symptoms, it is advised you to visit an optician immediately.

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What increases the risk for DME?

Following are the few things that may increase the risk of DME in people:

• Increased HbA1c levels (more than 7%) and having diabetes for a long duration may increase the risk of getting DME.
• Excess weight or obesity can lead to an increase in the number of damaged blood vessels and therefore increases the risk. 
• Individuals suffering from sleep apnoea and diabetes may also have DME.
• Females who have diabetes and hypertension have high risks of developing DME. However, regular check-ups may help prevent the development of DME in them. 

Ways to prevent DME

Following are the ways that can help you in reducing the risk of diabetic macular edema: 

• Keep your blood sugar, blood pressure and cholesterol levels under control as advised by your doctor.
• Have a thorough dilated eye test at least once every year or as advised by your doctor.
• Diabetic pregnant women should get a dilated eye exam at the earliest.
• Maintain a healthy routine with a balanced diet and regular exercises.
• Do not smoke or drink alcohol.

Pro tip: If you wear glasses or contact lenses and have diabetes, visit your opticians regularly as a part of regular eye health check.

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Treatment for DME

If you have this condition, you should first understand what caused DME in the first place. Based on the cause, treatment can be carried out. Treatment for DME can include the following: 

1. Intravitreal injections

In this process, steroids or anti-VEGF drugs are injected into the eye. It’s important to know that this treatment can’t restore sight if there’s already severe damage to the macula. However, it can help prevent further vision loss.

2. Laser treatment

Laser therapy is a widely used treatment to help slow down the leakage of fluid from the blood vessels. In cases where Diabetic Macular Edema (DME) has not affected the central part of the macula, patients can be treated with this laser therapy. The goal of this treatment is to maintain the vision that the patient has

3. Surgery

Surgery can be considered as the last treatment option. It is usually suggested when there are other complications along with this eye condition. These complications can range from scarring of tissue to the vitreous pulling on the macula. 

Frequently Asked Questions