Diabetic retinopathy is an eye condition that can cause vision changes and vision loss. There are four stages of diabetic retinopathy based on the findings of a dilated eye exam.
Diabetic retinopathy develops when high blood sugar levels damage the tiny blood vessels in the retina. The retina is at the very back of the eye.
The retina’s job is to process information and send images to the brain. When the retina is damaged, a person may notice changes in their vision.
In its early stages, diabetic retinopathy does not usually cause any symptoms. Regular eye exams can detect early changes in the retina.
During an eye exam, an eye doctor can get a closer look at the eye. If there is damage to the blood vessels in the retina, they may diagnose diabetic retinopathy.
Doctors grade diabetic retinopathy based on changes in the blood vessels in the retina. There are four stages.
This article explains how doctors grade diabetic retinopathy. It also goes over the stages and the outlook for the condition.
Diabetic retinopathy occurs in approximately
Early detection is an important part of treating diabetic retinopathy. Knowing the stage of diabetic retinopathy is also important so a person gets the most effective care to protect their vision.
There is a standard grading system optometrists use to diagnose the stage of diabetic retinopathy. It is based on:
- how many blood vessels are damaged
- the presence and size of tiny bulges in the blood vessels, called microaneurysms
- the growth of abnormal blood vessels
- the presence and amount of blood or other fluids leaking from blood vessels
Diabetic retinopathy has four stages. Over time, high blood sugar levels may cause the blood vessels to weaken. This may affect vision.
The early stages of diabetic retinopathy do not usually cause obvious symptoms. Often, a person will not have any changes in their vision until the condition has progressed.
Stage 1: Mild non-proliferative diabetic retinopathy (NPDR)
Doctors diagnose stage 1 when there is some early damage to the blood vessels in the retina.
An eye doctor will see tiny microaneurysms and no other abnormalities in the blood vessels. They appear as dots during an eye exam and show areas where blood flow is affected.
In stage 1, there is no abnormal blood vessel growth or any fluid leaking from blood vessels.
Usually, treatment is not needed at this point. Regular eye exams are an important part of care. A person may also work closely with their diabetes care team to improve their blood sugar levels.
Managing blood pressure is important to protect the eyes. Typically, the recommendation is to have a follow-up in a year.
Stage 2: Moderate NPDR
Stage 2 diabetic retinopathy is when there are microaneurysms present along with some other signs of damage. If retinopathy does not meet the criteria for severe but is more than just a few microaneurysms, as in stage 1, a person likely has moderate NPDR.
In the moderate stage, there may be small amounts of bleeding or fluid leaking from the blood vessels. This may typically be in more than one area.
Just like in stage 1, most people will not have any changes in their vision. Occasionally, a person will have moments of blurred vision. Many people have no symptoms.
Monitoring is important at this stage, but a person will typically not need treatment.
A person with moderate NPDR is recommended to do their best to manage blood sugar levels. Keeping blood pressure in a normal range can also help slow the progression of diabetic retinopathy. The recommendation is to have a follow-up in around 6 months.
Stage 3: Severe NPDR
There are specific criteria an eye doctor uses to diagnose stage 3 diabetic retinopathy. Stage 3 is also known as severe NPDR. To make this diagnosis, an eye doctor will use the 4-2-1 rule, which is discussed in the next section.
Severe NPDR includes microaneurysms throughout the retina and changes in the shape of the blood vessels. Blood flow is affected and new, weaker vessels may grow in the retina.
A person with stage 3 diabetic retinopathy may start to notice:
- blurred vision
- floaters in their vision
- trouble with night vision
In the severe stage, a person may begin treatment for diabetic retinopathy to prevent or slow progression. It is recommended to have a follow-up in 4 months.
Stage 4: Proliferative diabetic retinopathy
Stage 4 is the most advanced stage of diabetic retinopathy. At this stage, abnormal blood vessels are growing. These vessels are weak and prone to leaking. Fluid leaking from the vessels can cause swelling in the macula, the center point of the retina. When this happens, it’s called diabetic macular edema. It result in vision changes or loss of vision.
At this stage, a person may receive treatment to protect their vision or prevent further vision loss.
Eye doctors use the 4-2-1 rule to define severe NPDR, also known as stage 3 diabetic retinopathy.
During an exam, the eye is visually divided into four quadrants. The diagnosis of severe NPDR is based on how many quadrants include signs of damage.
For an eye doctor to make a diagnosis of severe NPDR, the following criteria must be met:
- Each of the four quadrants has vessels that are bleeding or have tiny bulges.
- At least two of the quadrants have venous beading. This means veins have sections that are wider than usual.
- At least one quadrant has abnormal blood vessels starting to grow.
Regular eye exams are important to monitor eye health and detect any conditions early.
In stage 1 or 2 diabetic retinopathy, a person does not typically need treatment. Instead, regular eye exams with an optometrist can monitor for changes in the eye.
To protect the eyes and slow the progression of diabetic retinopathy, a person can work with a healthcare professional to see whether blood sugar levels can be improved. Managing blood pressure and cholesterol can also help protect the blood vessels in the retina.
If someone receives a diagnosis of severe (stage 3) or proliferative diabetic retinopathy (stage 4), the person may begin treatment. Treatment for diabetic retinopathy includes:
- anti-VEGF medication injected into the eye to stop the growth of abnormal blood vessels
- steroid medication injected into the eye to reduce inflammation
- laser treatment to stop or reduce fluid leaking from the weak blood vessels
Treatments are an effective way to prevent further vision changes.
Diabetic retinopathy is an eye condition that can develop due to high blood sugar levels.
Diabetic retinopathy has four grades, or stages. During an eye exam, an eye doctor closely examines the eye to look for changes.
Based on the findings of the eye exam, diabetic retinopathy is graded as mild, moderate, or severe non-proliferative or proliferative diabetic retinopathy. “Proliferative” means new abnormal blood vessels are growing throughout the retina.
Getting regular eye exams and managing blood sugar, blood pressure, and cholesterol levels are all important parts of preventing or slowing the progression of diabetic retinopathy.
In later stages, a person may also start treatments to help prevent further vision changes.