How Does Diabetes Affect Your Vision?

This article is for people who have diabetes, or their care partners, as well as others who want to learn more about the effects of diabetes on vision. The goal is for patients to better understand diabetic retinopathy (damage to the retina of the eye) and to encourage patients to discuss screening and treatment with their doctor.

You will learn about:

• How diabetes puts you at risk for diabetic eye disease, including diabetic retinopathy

• Symptoms of diabetic retinopathy

• Why prevention is important

• Tests and screenings for diabetic retinopathy

• Diabetic retinopathy treatment

• Questions to ask your doctor

Diabetic eye disease is a group of eye conditions that can happen in people with diabetes. These conditions include diabetic retinopathy, diabetic macular edema, cataract, and glaucoma.

All of the conditions of diabetic eye disease can cause severe vision loss and blindness.

Diabetic retinopathy is the most common diabetic eye disease, and the most common cause of vision loss in people with diabetes.

Anyone with type 1, type 2, or gestational diabetes (during pregnancy) is at risk for diabetic retinopathy.

Your risk depends on:

• Your type of diabetes

• How long you've had diabetes

• How often your blood sugar (glucose) changes

• How well controlled your blood sugar levels are

Diabetic retinopathy is caused when your blood sugar (glucose) levels are high for a very long time.

When blood glucose is too high for too long, it blocks off small blood vessels in your retina (the tissue lining the back of your eye that changes light into the images that you see). These vessels weaken, and can bleed and leak fluid into the retina. This distorts your vision.

To fight this, your eye may try to grow new blood vessels, but they won't develop normally. As more vessels become blocked and as more new abnormal vessels grow, they cause scarring on your retina and damage your vision.

Diabetic retinopathy usually happens in both eyes.

Early on, diabetic retinopathy usually has no symptoms. There is no pain and your vision may not change until the disease becomes severe.

Bleeding in your retina may cause you to see "floating" spots. These spots sometimes go away on their own.

Contact your doctor right away if your vision changes suddenly or if you start having symptoms of diabetic retinopathy such as:

• A loss of central vision (fine, sharp, straight-ahead vision) when you read or drive

• Blurry or hazy vision

• Holes or black spots in your vision

• Inability to see colors

At first, you may not even know you have diabetic retinopathy because it usually has no symptoms in the beginning. This is why preventing it is so important.

Careful diabetes management -- taking medicines as prescribed, staying physically active, eating a healthy diet -- is the best way to prevent or delay vision loss. Keeping your blood pressure and cholesterol, as well as your blood sugar, under control can also help.

Because diabetic retinopathy often goes unnoticed until vision loss happens, you should get a complete eye exam at least once a year.

Regular screenings and tests can help with the prevention and early detection of diabetic retinopathy.

These can include:

• Blood sugar levels: Ask your doctor how often you should check and record your blood sugar levels. You may need to check them several times a day

• Hemoglobin A1C: This test is done by your doctor and shows your average blood sugar level for the previous 2 to 3 months. For most people, their A1C goal is to be < 7%

If you have diabetes, it's important to visit your eye doctor at least once a year for a complete eye exam with dilation, even if your vision seems fine. For dilation, your doctor will put drops in your eyes to widen (dilate) your pupils so they can see the back of your eye, including the retina.

If you're pregnant and have diabetes, get a thorough eye exam in your first trimester. Pregnancy may make diabetic retinopathy worse, so your doctor may also recommend additional eye exams during pregnancy.

Prompt treatment can help slow diabetic retinopathy. Finding and treating it early may even reverse some types of vision loss.

With mild diabetic retinopathy, you may not need treatment right away, but your doctor will monitor you closely.

If your condition is more severe, you may need eye surgery that can include:

• Laser surgery to seal off leaking blood vessels and shrink new abnormal vessels or stop them from growing

• Vitrectomy, which can help remove blood, fluid, and scar tissue

• Injection into the eye with medicine called vascular endothelial growth factor (VEGF) inhibitors, or anti-VEGFs, to help stop new abnormal blood vessels from growing

Prevention, early detection, timely treatment, and proper follow-up care all help protect against vision loss.

Questions to ask your doctor about diabetic retinopathy can include:

• How can diabetes affect my eyes?

• What types of diabetes are affected by diabetic retinopathy?

• If I control my blood sugar, will my eye symptoms get better?

• What tests or exams do I need and how often?

• Is this condition temporary or long lasting?

• What treatments are available?