How Diabetes Can Damage Your Eyes

Having diabetes puts you at risk for eye problems. Learn about diabetes-related eye conditions that can threaten your sight and how to avoid them.

By Regina Boyle Wheeler

Medically reviewed by Farrokh Sohrabi, MD andMatthew Dombrow, MD

Type 2 diabetescomplications can be widespread, affecting nearly every part of your body. One of the greatest threats is to your eyes. People with diabetes have a higher risk of developing serious eye problems than people without diabetes do.

Diabetes causes increased inflammation in the body, which is particularly evident in blood vessels both big and small, says Mario Skugor, MD, an endocrinologist at the Cleveland Clinic in Ohio. Problems with larger blood vessels can cause heart attacks and strokes, he says, while damage to smaller ones, the capillaries, can cause kidney and eye problems. “If you look in the eye of a person with diabetes, you will frequently see the damaged capillaries,” Dr. Skugor says.

Successfully managing diabetes and other health conditions and seeing an eye doctor regularly are key to keeping your eyes healthy. Here's what you need to know about diabetes-related eye problems.

Diabetic Retinopathy

Diabetic retinopathy, a common diabetes complication, is the leading cause of blindness in American adults, according to the U.S. Centers for Disease Control and Prevention. Up to 45 percent of people with diabetes have some form of diabetic retinopathy, according to the National Eye Institute.

The retina is the tissue at the back of the eye that perceives light, and keeping it healthy is necessary for clear vision. There are two types of diabetic retinopathy:

• Non-proliferative diabetic retinopathy is the most common form of retinopathy, according to the American Diabetes Association (ADA). In mild cases, blood vessels may swell and form fluid filled pouches within the retina. Early on, you may not even realize your eyes are being damaged, says Rishi Singh, MD, an ophthalmologist at the Cleveland Clinic. He explains that people might notice that their vision has become blurrier or that it’s more difficult to see in the dark. However, people often attribute these changes to normal aging. As the disease progresses, the vessels can become blocked, depriving the retina of blood flow.
• Proliferative diabetic retinopathyoccurs as more and more vessels are blocked and the retina starts to rapidly grow new, but immature and abnormal, blood vessels. These vessels have thin, fragile walls and, if they leak blood, severe vision loss and even blindness can occur. Sometimes these abnormal vessels can “contract” and cause a certain type of retina detachment called a tractional retinal detachment.

Treatment with lasers, drugs, or both can help, Dr. Singh says. But, Skugor adds that once damage has occurred, it’s difficult to recover lost vision — the primary goal of treatment is to slow down the progression and preserve what vision you have left. The earlier a diagnosis is made and treatment is started, the more likely it is that you’ll be able to retain good vision.

Macular Edema

About half of people with proliferative diabetic retinopathy also have macular edema. The macula is the part of the eye responsible for sharp, straightforward, central vision. If fluid leaks into the macula, it can cause swelling, which can make centralized vision blurry. Treatment for macular edema includes drugs, lasers, and eye injections.

Glaucoma

According to the ADA, people with diabetes are 40 percent more likely to get glaucoma than people without diabetes are. Your risk increases both with age and the longer you have diabetes.

With glaucoma, pressure builds up in the eye and damages the optic nerve, which sends signals from the retina to the brain. It’s estimated that three million Americans have glaucoma, but only half are aware that they have the eye condition. If left untreated, glaucoma can cause blindness.

Cataracts

People with diabetes are 60 percent more likely than those who don't have the disease to develop cataracts — when the lens of the eye becomes cloudy, causing blurry vision. Cataracts are usually age-related, but people with diabetes tend to develop this eye problem at an earlier age, and the condition may progress faster.

If cataracts are mild, getting new glasses or using sunglasses to reduce glare may help. If this doesn't help enough, surgery can remove your natural lens and replace it with an artificial one. But lens removal for people with diabetes has the potential to worsen retinopathy and possibly trigger glaucoma.

How to Avoid Diabetes-Related Eye Problems

To avoid damaging the blood vessels and developing eye problems, Skugor says, “you have to control your blood sugar, blood pressure, and cholesterol because they all contribute to the damage.” If you smoke, you should quit. Smoking has been linked to an increased risk for eye problems, including cataracts and optic nerve damage.

As part of managing diabetes, it’s also a must to have a dilated eye exam each year, and more often if you have retinopathy or significant eye disease, Singh says. Your eye doctor can detect even subtle changes in the condition of your eyes, and treating eye problems early on gives you the best chance of preserving your eyesight.