Proliferative diabetic retinopathy and non-proliferative diabetic retinopathy are stages of diabetic retinopathy. The former is the more severe form that can lead to vision loss.

Unmanaged diabetes can damage many tissues in your body, including your retina, the layer of cells in your eye that detect light. Diabetic-related damage to your retina is called diabetic retinopathy.

Read on about these two stages of diabetic retinopathy, including symptoms and how they’re treated.

Doctors have used different staging systems for diabetic retinopathy over the years. The current gold standard classification system is the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification.

Under the ETDRS classification, doctors stage NPDR and PDR based on the appearance of your retina.

The stages of NPDR include:

StageFeature
No retinopathyno abnormal areas on your retina
Very mild NPDRbulges in small blood vessels in your retina called microaneurysms
Mild NPDRa few microaneurysms, areas of bleeding called retinal hemorrhages, and yellowish flecks called exudates
Moderate NPDRretinal bleeding in 1 to 3 of your retina’s 4 quadrants as well as opaque, fluffy patches called cotton wall spots caused by lack of blood flow
Severe NPDRfulfilling 1 of the 3 following criteria:

• severe bleeding in all 4 retina quadrants
• venous beading in 2 or more quadrants, which is when your veins swell and appear as strings of sausage
• moderate intraretinal microvascular abnormalities, which are stretching or deformity in your blood vessels
Very severe NPDRfulfilling 2 or more of the 3 features above

PDR is a more severe type of diabetic retinopathy. Stages of PDR include:

StageFeature
Mild to moderate PDRretinal neovascularization, which is the development of new and abnormal blood vessels that can cause vision loss
High risk PDRmore severe neovascularization or neovascularization with vitreous hemorrhage, where blood floats in the gel inside your eye
Advanced diabetic eye diseasethe end stage of diabetic retinopathy, which can involve severe vision loss and other serious complications

Learn more about the stages of diabetic retinopathy.

Here are the potential symptoms of these two stages of diabetic retinopathy.

Non-proliferative diabetic retinopathy symptoms

You might not have noticeable symptoms in the early stages of NPDR. As it progresses, you may develop blurry vision due to swelling of your retina and macula. The macula is the part of your retina that’s responsible for your central vision. Symptoms tend to be progressive as your disease becomes more advanced and may also include:

Proliferative diabetic retinopathy symptoms

PDR causes the same symptoms, but they tend to be more serious. It can lead to complications that may result in severe blindness.

Chronically high blood sugar in people with diabetes causes diabetic retinopathy. High blood sugar can damage the blood vessels that supply your retina and impair your retina’s blood supply.

High blood sugar levels can damage blood vessels throughout your body, but diabetic retinopathy is the most common complication of diabetes.

If you’ve previously received a diagnosis of diabetes, it’s important to see your doctor for regular check-ups to monitor for complications. If you’ve previously received a diagnosis of diabetic retinopathy, it’s important to seek prompt medical attention if you notice worsening changes to your vision.

A doctor will start the diagnosis by reviewing your medical history, performing an eye exam, and considering factors like:

  • the duration of your diabetes
  • the type of diabetes
  • your past diabetes medications
  • the presence of other conditions like obesity or kidney disease

An eye doctor can examine your retina with a test called fundoscopy where they dilate your eyes with drops and use a special tool with a light and magnifying glass to examine your retina. If they see anything abnormal in your retina, they might also order imaging tests, such as:

To prevent further retinal damage, you should follow proper diabetes treatment to keep blood sugar levels within a safe range. This often requires a combination of medications and lifestyle changes.

Learn more about type 2 diabetes treatment.

Specific treatments for damage to your eye might include:

You may be able to prevent diabetic retinopathy by taking steps to avoid type 2 diabetes, such as:

  • losing weight if you’re overweight
  • exercising regularly
  • getting adequate sleep
  • minimizing your intake of added sugars
  • eating mostly whole foods as opposed to highly processed foods
  • consuming plenty of fiber and protein

Learn more about preventing type 2 diabetes.

If you already have diabetes, you may be able to prevent complications by following your treatment plan and going to all your follow-up appointments. Your follow-up schedule will likely depend on the severity of your disease but may look something like this for people with NPDR:

Severity of NPDRFollow-up
very mildevery year
mild to moderateevery 6 to 12 months
severe to very severeevery 2 to 4 months

Diabetic retinopathy is a common complication of diabetes. It’s divided into NPDR and PDR depending on whether you have new and abnormal blood vessels growing around your retina. PDR is the more severe form.

People with diabetic retinopathy need to make sure their diabetes is well-managed to help prevent vision loss. It’s important to go to all your scheduled follow-ups and take your medications as prescribed.