What to Know About Diabetic Retinopathy

Type 1 and type 2 diabetes can lead to the vision-threatening condition known as diabetic retinopathy. High blood sugar in poorly controlled diabetes can damage vessels in the light-sensing retina in the back of the eye. This potentially leads to complications that can threaten your vision.

Initially, diabetic retinopathy may cause only mild vision problems. As the retina is damaged, it becomes more serious, potentially leading to vision loss or blindness. The good news is that vision loss from diabetic retinopathy is preventable.

This article covers everything you need to know to keep diabetic retinopathy from causing vision damage. It explains what happens if you have diabetic retinopathy, the stages of the disease, symptoms to watch for, what's involved with diagnosis and treatment, and more.

Diabetic retinopathy results from damage to blood vessels in the retina.

What Happens If You Have Diabetic Retinopathy

If you have any form of diabetes, you are vulnerable to diabetic retinopathy. High blood sugar levels can damage blood vessels in the retina. This damage can cause blood vessels to either leak or close up, shutting down blood flow in the area.

Sometimes, the damaged blood vessels are replaced by leaky new ones on the retina that don't function properly. Any of these retinal issues can cause problems with your sight.

Diabetic Retinopathy Stages

The two types of diabetic retinopathy are nonproliferative and proliferative. The nonproliferative form of the disease occurs first. This is an early stage in which new blood vessels have not yet begun to form. In the later proliferative form, these have started to spread across the retina.

Your eye doctor will find you to be in one of four stages, as follows:

  • Stage 1: Mild nonproliferative retinopathy: At this stage, small outpouchings (microaneurysms) can begin to occur in some retinal blood vessels. These blood vessels can begin to leak and start to cause damage to the retina.
  • Stage 2: Moderate nonproliferative retinopathy: In this stage, the blood vessels begin to shut down, stopping needed blood flow to the retina, which normally nourishes it.
  • Stage 3: Severe nonproliferative retinopathy: At this stage, many blood vessels have closed down, and areas of the retina are no longer getting the nourishment they need. To compensate, the retina sends signals for new blood vessels to develop in the damaged areas.
  • Stage 4: Proliferative retinopathy: During this late stage, new blood vessels begin to form. These readily grow on the retina and the clear jelly at the back of the eye. The catch is that these are very abnormal and tend to leak easily. It is this leakage that ultimately causes damage to the retina, potentially leading to severe vision loss and even blindness.

Diabetic Retinopathy Symptoms

Initially, diabetic retinopathy has no symptoms. But with time, you may begin to notice some early signs, such as the following:

  • Difficulty reading
  • Trouble seeing far away
  • Fluctuating vision
  • Poor night vision
  • Color appear faded

As the disease progresses, symptoms can include things such as:

  • Spots, streaks, or cobwebs in your vision are caused by shadows from blood leaking into the jellylike substance in your eye. Be sure to report this right away so that it can be treated before it affects your vision further.
  • Blind spots in your vision due to scarring on the retina are caused by blood on the retina that is left untreated.

What Causes Diabetic Retinopathy?

Chronic high blood sugar is responsible for the vision issues caused by diabetic retinopathy. The increased blood sugar levels damage the retina's vessels by causing blood vessels to leak.

This condition can develop from type 1 diabetes, often diagnosed in children and adolescents. Type 2 diabetes is responsible for over 90% of diabetes cases. It usually is diagnosed in midlife but can happen earlier. Gestational diabetes develops during pregnancy. It can lead to retinopathy or worsen existing retinopathy.

Fortunately, if you control your sugar levels, you can potentially reduce any eye damage. Some risk factors that can make you particularly vulnerable to vision loss include:

In people between the ages of 20 and 74, diabetic retinopathy is the leading cause of vision loss.

How Is Diabetic Retinopathy Diagnosed?

To determine if you have diabetic retinopathy, your ophthalmologist or optometrist will give you a thorough diabetes eye exam. This will include taking your history and looking in your eye for signs of the disease. They may also perform targeted testing. Here's what you can expect.

Dilated Eye Exam

To check the inside of your eye, your ophthalmologist or optometrist will place drops in your eyes that dilate (widen) the dark pupil at the center of your eye. This is quick and doesn't hurt, but your vision will temporarily blur until your pupil returns to normal.

Fluorescein Angiography

Fluorescein angiography can help detect changes in your blood vessels. As part of the test, a chemical known as fluorescein, which can light up blood vessels, is injected into your bloodstream.

After injecting the dye, the ophthalmologist uses a special camera to shine blue light into the eye. The retinal blood vessels appear a fluorescent green. Images taken can help identify leaks.

Optical Coherence Tomography

This test can be used to create three-dimensional (3D) imaging of retinal blood vessels to get a detailed view. It can also help determine the thickness of the retina to detect swelling.

Diabetic Retinopathy Treatment

Diabetic retinopathy currently has no cure, but treatment can help slow the progression of the disease. If this is done soon enough, you may be able to preserve vision. Your ophthalmologist may suggest one of the following approaches.

Controlling Your Blood Sugar and Blood Pressure

Maintaining good blood sugar and blood pressure control can help prevent the progression of diabetic retinopathy. Work with your healthcare provider to find the right combination of medications, diet, exercise, and other lifestyle modifications to achieve the best blood sugar levels and blood pressure range.

Laser Treatments

Laser photocoagulation uses a laser to treat the retina. The laser can seal blood vessels, shrinking them and potentially keeping new vessels from developing. This technique can also reduce fluid in the macula (macular edema) at the center of the retina.

Injections

In some cases of diabetic retinopathy, the eye makes too much vascular endothelial growth factor protein, which can cause new blood vessels to form. Anti-vascular endothelial growth factor (VEGF) injections into the eye can block these proteins and keep new abnormal blood vessel formation at bay.

Some anti-VEGF drugs include the following:

  • Avastin (bevacizumab)
  • Beovu (brolucizumab)
  • Eylea, Eylea HD (aflibercept)
  • Lucentis (ranibizumab)
  • Vabysmo (faricimab)

Eye Surgery

With diabetic retinopathy, blood in the vitreous (jelly of the eye) can unfortunately cloud your vision. In some cases, a surgical procedure known as a vitrectomy can help. This involves removing the jelly in the eye and replacing it with a clear substitute such as fluid, silicone oil, or gas.

Can Diabetic Retinopathy Be Prevented?

Keeping your blood sugar levels in check and other health factors such as blood pressure and cholesterol down can lower your risk of developing diabetic retinopathy.

Maintaining a healthy lifestyle with a balanced diet, regular exercise, and keeping your weight down can also help reduce your risk. It's also important to avoid smoking and to drink alcohol only in moderation, if at all.

People with diabetes should get their eyes screened regularly for diabetic retinopathy and other eye conditions associated with diabetes every one to two years. People at risk of developing diabetes should get regular health screenings to detect and treat the condition early.

Diabetic Retinopathy Complications

In some cases, diabetic retinopathy can result in other eye problems. Here are some complications that may arise.

  • Diabetic macular edema (DME) is a complication in which fluid from blood vessels leaks onto a part of the retina known as the macula. The macula is responsible for sharp vision. When this is compromised, sight becomes blurry. DME affects about 1 in 15 people with diabetes.
  • Neovascular glaucoma develops when abnormal new blood vessels form on the retina and interfere with the eye's drainage system. This can cause a buildup of fluid in the eye. This condition can lead to vision loss or blindness.
  • Retinal detachment can occur if blood leaks onto the retina and a scar forms. This scar can tug on the retina and cause it to pull away from the back of the eye. If the retina is not promptly reattached, sight in the eye will be lost.

When to Contact a Healthcare Provider

If you have diabetes, being proactive about your eye health is important. Get a dilated eye exam as recommended by your healthcare provider. Generally, this is every one to two years if you have no signs of diabetic retinopathy or you have stage 1 disease without DME. It can be every few months if you have a later stage.

For those who already have this condition, it's vital that you promptly report any changes in your vision to your ophthalmologist immediately. While treatment may be able to prevent damage to the retina before this occurs, once it happens, it cannot be undone, and any related vision loss is permanent.

Summary

If you have any form of diabetes, you are at risk of developing diabetic retinopathy. With this condition, sugar in the blood damages retinal vessels, which can leak and threaten vision. You will likely be monitored closely for any signs that you are developing diabetic retinopathy.

While there is no cure for this condition, treatments can help to slow the progression and help to preserve vision.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Maxine Lipner

By Maxine Lipner
Maxine Lipner is a long-time health and medical writer with over 30 years of experience covering ophthalmology, oncology, and general health and wellness.