If you have diabetes, you may get a condition called diabetic retinopathy. This eye disease happens when high levels of blood sugar damage blood vessels in a part of your eye called the retina. This can cause vision problems. For people with diabetes, it’s the most common cause of vision loss and blindness.
You may be able to keep from getting it. If you do get it, there are ways to slow it down. Almost half of people with diabetes have some level of it. People in early stages without symptoms may not know they have it.
Diabetic retinopathy can go through four stages:
Mild Nonproliferative Retinopathy
The first stage is also called background retinopathy. It means that there are tiny bulges in the tiny blood vessels in your retinas. The bulges are called microaneurysms. They may cause the vessels to leak small amounts of blood into your retinas.
At this early stage, you probably don’t have vision problems, so you may not need treatment. Talk to your doctor about ways to keep your condition from getting worse. You'll need to keep your blood sugar, blood pressure, and cholesterol levels under control. You should plan to have another screening test in 12 months.
If the doctor diagnoses you with this condition in both eyes, you have a 25% chance of progressing to the third stage in the next 3 years.
Moderate Nonproliferative Retinopathy
The second stage is also called pre-proliferative retinopathy. At this stage, the blood vessels in your retinas swell. They may not carry blood as well as they used to. These things can cause physical changes to the retina.
These changes can lead to diabetic macular edema (DME). This happens when blood and other fluids build up in a part of your retina called the macula. The macula is key for straight-ahead vision, like when you read or drive. When it swells, it can cause problems with this important part of your vision.
Half the people with diabetic retinopathy will get DME. It can happen at any stage, but it’s more likely to happen as the condition advances.
Reaching this stage means a greater chance that the disease will affect your vision. Your doctor may recommend eye tests every 3 to 6 months.
Severe Nonproliferative Retinopathy
This is also called proliferative retinopathy. In this stage, your blood vessels become even more blocked. This means even less blood goes to the retinas. Because of this, scar tissue forms. The lack of blood triggers a signal to your retinas to create new blood vessels.
If the blood vessels close off completely, it's called macular ischemia. This can lead to blurry vision with dark spots some people describe as “floaters.”
If you reach this stage, there’s a very high chance that you’ll lose your vision. Treatment may be able to stop further vision loss. But if you’ve already lost some of your vision, it’s unlikely to come back.
Proliferative Diabetic Retinopathy (PDR)
In this advanced stage, new blood vessels grow in your retinas and into the gel-like fluid that fills your eyes. This growth is called neovascularization. These vessels are thin and weak. They often bleed. The bleeding can cause scar tissue.
As the scar tissue gets smaller, it can pull the retina away from the back of your eye. This is called retinal detachment. It can lead to permanent loss of both straight-ahead and side vision.
What Stage Do I Have?
To diagnose diabetic retinopathy, your doctor will give you a diabetic eye screening. They may test your ability to see at different distances. They may test the pressure inside your eye. They may put drops in your eyes to make your pupils bigger, which lets the doctor see inside your eye.
The doctor may do an optical coherence tomography (OCT) scan. It uses light waves to take pictures inside your eyes.
One final test the doctor may use is a fluorescein angiogram. This is when they inject dye into your vein, often in the arm. The dye travels to your eyes. Then the doctor will take photos of the dye in your eye’s blood vessels to look for leaks and damage.
All of these tests will help your doctor diagnose the stage of your diabetic retinopathy.
Treatment of Diabetic Retinopathy
Your doctor will likely watch your condition until you're close to the latest stage or get DME. When that happens, there are several treatments you can try. Your doctor may give you a shot in the fluid of your eyes to keep abnormal blood vessels from growing. They may also suggest laser surgery. They may also give you a shot or an implant of steroid drugs directly into your eye. You may need more than one of these treatments at the same time.