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What is Diabetic Retinopathy?

Diabetic retinopathy is a condition that can occur in patients with diabetes. The most common cause of vision loss for people with diabetes, diabetic retinopathy is caused by damage to the blood vessels due to diabetes. This damage can cause the tissue in the retina - the light-sensitive lining at the back of the eye - to swell, which leads to cloudy or blurred vision, and in some cases blindness.1-3

What causes diabetic retinopathy?

Diabetes prevents the body from normally using and storing sugar, or glucose, in the blood. When a person has diabetes that is not being well-managed, chronic high blood sugar can occur, which eventually can lead to damage of the tiny blood vessels in the retina. These blood vessels may swell, leak, or even bleed, all of which can disturb your vision.1-3

Diabetic retinopathy is when this damage causes the tissue in the retina to swell, which results in cloudy or blurred vision. If left untreated, diabetic retinopathy can lead to blindness.2

What are the four stages?

Early detection and treatment can help diabetic retinopathy and ultimately prevent blindness. However, if left untreated, diabetic retinopathy typically progresses through the following four stages1:

  1. Mild nonproliferative retinopathy: Small areas of swelling in the retina’s blood vessels occur, sometimes leaking fluid into the retina.
  2. Moderate nonproliferative retinopathy: Damaged blood vessels begin to swell and distort and can lose their ability to move blood through the retina. The appearance of the retina can begin to change.
  3. Severe nonproliferative retinopathy: More blood vessels become blocked which decreases the retina’s blood supply. Growth factors begin to trigger the growth of too many blood vessels.
  4. Proliferative diabetic retinopathy (PDR): Leaky, fragile blood vessels continue to grow inside the surface of the retina and the fluid that fills the eye. Scar tissue may develop and cause retinal detachment, which can lead to permanent blindness.


Unfortunately, a patient with diabetes may develop diabetic retinopathy and not know it. The early stages of disease are usually asymptomatic. Oftentimes, the disease is present but is not noticed until it begins to affect vision. As the disease progresses, symptoms may become more apparent inlcuding 1,3:

  • Seeing blurry spots, or “floaters” in your vision, which may come and go
  • Blurred vision
  • Vision changes back and forth from blurry to clear
  • Dark or blank areas in your field of vision
  • Poor night vision
  • Faded or washed out colors in your vision

Diabetic retinopathy also typically affects both eyes.3

How do you prevent it?

The best way to prevent diabetic retinopathy if you have diabetes is to control your blood sugar and keep the blood vessels in the retina healthy. Be sure to follow any dietary recommendations given to you by your healthcare provider and take any medication as prescribed.4

How is it diagnosed?

Since the early stages of diabetic retinopathy usually do not cause symptoms, it is important that patients with diabetes get a comprehensive eye exam at least once every year. Early detection and treatment can reduce the risk of blindness by 95%.1


There are treatment options available for more advanced stages of disease.


One medication available is called anti-VEGF medication. Anti-VEGF medication, such as brands Avastin, Eylea, and Lucentis, help to reduce swelling of the macula around the retina, which can slow vision loss or improve vision. Steroids are another option to treat the swelling caused by diabetic retinopathy. Both forms of medication are given by injection into the eye.4

Laser surgery

Sometimes surgery may be recommended for advanced stages of PDR. Laser treatment can be used to try and seal off leaking blood vessels in the retina.2 Other laser procedures called panretinal laser surgery or panretinal coagulation works by laser burning areas in the retina to promote shrinkage of the retina’s blood vessels. This treatment can help central vision, but may cause a loss of side vision, color, or night vision. This type of treatment works best before blood vessels in the retina have begun to bleed.1


Another option for advanced PDR is a surgery called vitrectomy. This procedure removes gel and blood leaking from the vessels in the back of the eye. Light rays once again become able to focus on the retina, improving vision. Scar tissue may also be removed from the retina during this procedure.4

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