What is diabetic retinopathy?

Diabetic retinopathy is a leading cause of blindness in American adults. Changes in the blood vessels of the retina, the light sensitive layer of tissue at the back of the inner eye, can lead to this condition. In some people, retinal blood vessels may swell and leak fluid. In others, abnormal new blood vessels grow on the surface of the retina. These changes may result in vision loss or blindness.

While you can’t completely prevent diabetic retinopathy, you can reduce your risk of getting it. Controlling your blood sugar slows the start of retinopathy. It also keeps it from getting worse. It also lessens the need for laser surgery for severe retinopathy.

Diabetic eye disease refers to a group of eye problems that people with diabetes may face. All can cause severe vision loss or even blindness. Fortunately, diabetic eye disease often can be treated before vision loss occurs. All people with diabetes need a dilated eye exam at least once a year.

Diabetic eye diseases include:

• Diabetic retinopathy

• Cataracts

• Glaucoma

• Diabetic macular edema

Diabetic retinopathy is the most common eye disease in people with diabetes.

What causes diabetic retinopathy?

Changes in the blood vessels of the retina cause diabetic retinopathy. In some people with diabetic retinopathy, the blood vessels in the retina may swell and leak fluid. In others, abnormal new blood vessels grow on the surface of the retina. These changes may result in vision loss or blindness.

Who is at risk for diabetic retinopathy?

Anyone with diabetes is at risk for diabetic retinopathy. The longer you have diabetes, the more likely you are to develop diabetic retinopathy. Your risk rises if you have diabetes and you smoke, have high blood pressure, sleep apnea, or are pregnant.

What are the symptoms of diabetic retinopathy?

In the early stages of diabetic retinopathy, you may have no symptoms. This is one of the reasons a regular eye exam is so important. Vision may not change until the disease gets worse. Then you may have blurry or double vision, dark or floating spots, pain or pressure in one or both eyes, rings, flashing lights, or blank spots in your vision.

A condition called macular edema may occur from diabetic retinopathy. It happens when the macula, a part of the retina, swells from the leaking fluid and causes blurred vision. When new vessels grow on the surface of the retina, they can bleed into the eye. This may decrease vision.

How is diabetic retinopathy diagnosed?

Along with a complete health history and eye exam, your eye care provider may do these tests to diagnose diabetic retinopathy:

• Visual acuity test. This is the common eye chart test. It measures vision ability at various distances.

• Tonometry. This standard test is done to check the pressure (intraocular pressure, or IOP) inside the eye.

• Pupil dilation. For a close-up exam of the eye’s lens and retina, your pupil is widened (dilated) with eye drops. 

• Ophthalmoscopy. This is a test where a healthcare provider looks very closely at the retina using a special magnifying glass.

• Fluorescein angiography. In this test, a dye is injected into the bloodstream. The dye helps the blood vessels in the eye show up while pictures are taken with a special camera. This test lets the healthcare provider see if the blood vessels are leaking. 

• Optical coherence tomography. In this test, light waves are used to make detailed images of the retina.

• Retinal photography. In this test, photos are taken of the retina of the eye that are reviewed by eye specialists to diagnose retinopathy and to follow its progression over the years. Your pupil isn't dilated.

How is diabetic retinopathy treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Even people with advanced retinopathy have a good chance of keeping their vision if they are treated before the retina becomes severely damaged. Treatment for diabetic retinopathy may include:

• Laser surgery. This is often used to treat macular edema and proliferative retinopathy. It includes shrinking the abnormal blood vessels or sealing the leaking ones.

• Vitrectomy. Vitrectomy is a procedure that involves removing the cloudy, jelly-like substance (vitreous) that fills the center of the eye. The vitreous is replaced with a saline solution.

• Injections. Certain chemicals can be injected into the eye to slow the growth of the abnormal vessels of the retina.

Can diabetic retinopathy be prevented?

You can't prevent diabetic retinopathy. But here are some ways to reduce the risk of developing it:

• Have a dilated eye exam once a year. An eye exam doesn't prevent retinopathy. But it can help diagnose eye problems that can then be treated. An eye exam can also alert you and your healthcare provider if the diabetes needs to be better controlled.  

• If you're a woman with diabetes, have an eye exam before pregnancy or in the first trimester. Continue to be watched every trimester and for 1 year after your baby's birth, depending on how severe the retinopathy is.

• Stop smoking and stay away from secondhand smoke.

Follow your diabetes management plan by:

• Taking medicines as directed

• Using insulin as directed, if needed

• Eating to manage blood sugar level

• Exercising to lower and help the body use blood sugar. Be careful not to strain a lot when exercising if you already have signs of certain forms of diabetic retinopathy. These include advanced or proliferative retinopathy.

• Testing blood-sugar levels regularly

• Testing urine for ketone levels regularly

• Regular healthcare follow-up to evaluate diabetes control and rule out or treat other risk factors, such as high blood pressure 

Better control of blood sugar slows the start and progression of retinopathy. And it lessens the need for laser surgery for severe retinopathy.

Key points about diabetic retinopathy

• Changes in the blood vessels of the retina cause diabetic retinopathy. Retinal blood vessels may swell and leak fluid. Or new blood vessels may grow on the surface of the retina. These changes may result in vision loss or blindness.

• Anyone with diabetes is at risk for diabetic retinopathy. The longer you have diabetes, the more likely you are to develop diabetic retinopathy.

• Treatment for diabetic retinopathy may include laser surgery, vitrectomy, and injection of chemicals to stop new blood vessels from forming.

• Healthy behaviors can help reduce the risk of diabetic retinopathy. These include not smoking, exercising, healthy eating, and having yearly eye exams. For women, it also includes having an eye exam before pregnancy or in the first trimester.

• Better control of blood sugar slows the start and progression of retinopathy. It also lessens the need for laser surgery for severe retinopathy.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.