Diabetic retinopathy is a progressive condition that causes damage to the retina in four stages. The retina is a layer of cells on the back wall of the eye that helps process light and produce vision.
Monitoring and treatment can help slow progression and reduce vision loss at each diabetic retinopathy stage.
Read on to learn more about the diabetic retinopathy stages, including their symptoms, diagnosis, and treatment.
There are four main stages of diabetic retinopathy:
- mild nonproliferative retinopathy, R1
- moderate nonproliferative retinopathy, R2
- severe nonproliferative retinopathy, R3
- proliferative retinopathy, R4
Stage 1: Mild nonproliferative retinopathy
The first stage of diabetic retinopathy is mild nonproliferative retinopathy, or background retinopathy. You may not have symptoms at this stage, but damage to the eye has started.
Damage includes tiny bulges or microaneurysms in the retina’s blood vessels. Microaneurysms may leak small amounts of fluids and blood, causing swelling in the macula. The macula is a central part of the retina.
At this stage, regular monitoring is necessary.
Read more about diabetic retinopathy microaneurysms.
Stage 2: Moderate nonproliferative retinopathy
Moderate nonproliferative retinopathy involves more microaneurysms and worse swelling. You may begin to notice symptoms at this stage, including:
- generally worsening vision, such as difficulty reading or seeing faraway
- vision problems that come and go
- blurry vision
- blank or dark areas in your vision
- difficulty seeing in low light
- seeing colors as more faded
- seeing floaters
Stage 3: Severe nonproliferative retinopathy
As diabetic retinopathy progresses to stage 3, worsening microaneurysms and swelling affect more of the retina. Larger areas of bleeding may occasionally cause you to see dark, floating streaks in your vision.
You may also experience exudates or “cotton wool spots,” small deposits in the eye that blur vision.
Eventually, the damage from severe nonproliferative retinopathy may cause blood vessels in the retina to close off. This can prevent enough blood and oxygen from reaching the macula.
Learn more about nonproliferative diabetic retinopathy.
Stage 4: Proliferative diabetic retinopathy
With proliferative diabetic retinopathy, the retina grows new, fragile blood vessels as a result of previous damage. These fragile blood vessels have a higher chance of leaking and can lead to scar tissue.
Eventually, the damage can cause vision loss.
Severe diabetic retinopathy can also cause further conditions or complications, including:
- Diabetic macular edema (DME): DME occurs when damaged blood vessels bleed into the macula. The macula is responsible for clear central vision, so DME can cause blurriness.
- Neovascular glaucoma: This occurs when new blood vessels that grow block fluid from draining out of the eye. Pressure can build up and cause vision loss.
- Retinal detachment: Advanced diabetic retinopathy can cause scarring in the back of the eye. Sometimes, this scarring may pull the retina away from where it is attached.
Read more about proliferative diabetic retinopathy.
A comprehensive dilated eye exam can confirm diabetic retinopathy and its stage. Early stages of many eye conditions, including diabetic retinopathy, do not cause noticeable symptoms.
Even if you begin to experience symptoms, an eye doctor will need to examine your eyes to measure diabetic retinopathy progression.
Tests to monitor the stage of diabetic retinopathy and vision damage include:
- Optical coherence tomography (OCT): A machine provides detailed images of the retina to show swelling and check for blood vessel changes.
- Fluorescin angiography: Doctors inject a dye into the arm and track its movement through the blood vessels to look for problems.
If you have diabetes, ask an eye doctor about how often you should get a comprehensive eye exam.
Early treatment can help slow or stop diabetic retinopathy progression and prevent further vision loss.
Key treatment approaches for slowing diabetic retinopathy include:
- management of blood sugar and blood pressure levels according to your medical team’s advice
- steroid medications to reduce swelling
- anti-VEGF medications, which may help slow vision loss or improve vision
- laser surgery, to close off leaking blood vessels and shrink new, fragile blood vessels
- vitrectomy surgery, to remove scar tissue and blood
Read more about vitrectomy surgery, including its procedure.
Anti-VEGF medications are usually given as monthly injections and can include:
- aflibercept (Eylea)
- bevacizumab (Avastin)
- brolucizumab (Beovu)
- faricimab (Vabysmo)
- ranibizumab (Lucentis)
To improve the outcome with diabetic retinopathy, get early treatment. Also keep blood sugar levels within target ranges. Regular eye and diabetes checkups are key, even if you do not have symptoms.
Learn more about the outlook with diabetic retinopathy.
The four primary stages of diabetic retinopathy are:
- mild nonproliferative
- moderate nonproliferative
- severe nonproliferative
- proliferative
In nonproliferative stages, microaneurysms in the eye cause bleeding and swelling, eventually damaging vision. As the condition progresses to proliferative diabetic retinopathy, new blood vessels grow and cause more damage.
Early treatment can slow or stop diabetic retinopathy progression and vision loss.
Talk with your doctor about regular eye checkups or if you have vision symptoms.