Diabetic retinopathy is a condition that occurs as a result of damage to the blood vessels of the retina in people who have diabetes. Diabetic retinopathy can develop if you have type 1 or 2 diabetes and a long history of uncontrolled high blood sugar levels. While you may start out with only mild vision problems, you can eventually lose your sight. Untreated diabetic retinopathy is one of the most common causes of blindness in the United States, according to the National Eye Institute. It’s also the most common eye disease in people with diabetes.
Nonproliferative diabetic retinopathy (NPDR)
NPDR is also known as background retinopathy. It’s called "nonproliferative" because the eye doesn’t make new blood vessels during the early stages of diabetic retinopathy. During the early stages of retinopathy, damaged blood vessels often leak blood and fluid into the eye. In some cases, the center of the retina, or macula, begins to swell. This causes a condition called macular edema. The three stages of NPDR are mild, moderate, and severe, which may progress to the other type, or fourth stage, proliferative diabetic retinopathy.
Proliferative diabetic retinopathy (PDR)
Proliferative diabetic retinopathy, or advanced retinopathy, is the stage of retinopathy in which new blood vessels begin to grow within the retina. These new blood vessels are usually abnormal and grow in the center of the eye.
It’s uncommon to have symptoms during the early stages of this condition. The symptoms of diabetic retinopathy often don’t appear until major damage occurs inside of the eye. You can prevent unseen damage by keeping your blood sugar levels under good control and getting regular eye exams to monitor your eye health.
When the symptoms do appear, they’re most commonly seen in both eyes and can include:
- seeing floaters or dark spots
- difficulty seeing at night
- blurred vision
- a loss of vision
- difficulty distinguishing colors
High levels of sugar in the blood over long periods cause diabetic retinopathy. This excess sugar damages the blood vessels that supply the retina with blood. High blood pressure is also a risk factor for retinopathy.
The retina is a layer of tissue in the back of the eye. It’s responsible for changing images that the eye sees into nerve signals that the brain can understand. When blood vessels of the retina are damaged, they can become blocked, which cuts off some of the retina’s blood supply. This loss of blood flow can cause other, weaker blood vessels to grow. These new blood vessels can leak and create scar tissue that can cause a loss of vision.
The longer you have diabetes, the higher your chances of developing diabetic retinopathy become. Nearly everyone who has diabetes for more than 30 years will show some signs of retinopathy. Keeping your diabetes under control can help slow the progression.
Women with preexisting diabetes who are pregnant or are planning to become pregnant should have a comprehensive eye exam to determine if they have retinopathy.
Your doctor can diagnose diabetic retinopathy using a dilated eye exam. This involves the use of eye drops that make the pupils open wide, allowing you doctor to get a good look at the inside of your eye. Your doctor will check for:
- abnormal blood vessels
- leaking of the blood vessels
- blocked blood vessels
- changes to the lens
- damage to the nerve tissue
- retinal detachment
They may also perform a fluorescein angiography test. During this test, your doctor will inject a dye into your arm, allowing them to track how the blood flows in your eye. They’ll take pictures of the dye circulating inside of your eye to determine which vessels are blocked, leaking, or broken.
An optical coherence tomography (OCT) exam is an imaging test that uses light waves to produce images of the retina. These images allow your doctor to determine your retina’s thickness. OCT exams help determine how much fluid, if any, has accumulated in the retina.
Treatment options are limited for people who have early diabetic retinopathy. Your doctor may want to perform regular eye exams to monitor eye health in case treatment becomes necessary. An endocrinologist can help to slow the progression of retinopathy by helping you optimally manage your diabetes.
In advanced diabetic retinopathy, the treatment depends on type and severity of retinopathy.
Photocoagulation surgery can help prevent vision loss. This type of surgery uses a laser to control or stop leakage by burning the vessels to seal them. The types of photocoagulation and other treatments include the following:
- Scatter photocoagulation involves using a laser to burn hundreds of tiny holes in the eyes two or more times to reduce the risk of blindness.
- Focal photocoagulation involves using a laser to target a specific leaky vessel in the macula to keep macular edema from worsening.
- Vitrectomy involves removing scar tissue and cloudy fluid from the vitreous fluid of the eye.
If you have diabetes, it’s important to maintain healthy levels of the following to prevent diabetic retinopathy:
- blood pressure
- blood sugar
Other ways to prevent or manage the condition include the following:
- Quit smoking if you smoke.
- Get regular, moderate exercise several times per week. If you have retinopathy, check with your healthcare team to determine the best exercises for you.
- Get annual eye exams.
Diabetic retinopathy is a serious eye condition that can lead to diminished eyesight or even blindness in those with diabetes. If your doctor has diagnosed you with diabetes, it’s important to do the following:
- Get regular eye exams and physical checkups.
- Keep your blood sugar, cholesterol, and blood pressure at healthy levels.
- Be mindful of any changes you may notice in your vision, and discuss them with your doctor.
Medically Reviewed by: Peggy Pletcher, MS, RD, LD, CDE
Published By: Healthline Networks, Inc.