Diabetes and Vision Loss
Diabetes can damage your eyes over time and cause vision loss, even blindness. The good news is managing your diabetes and getting regular eye exams can help prevent vision problems and stop them from getting worse.
Eye diseases that can affect people with diabetes include diabetic retinopathy, macular edema (which usually develops along with diabetic retinopathy), cataracts, and glaucoma. All can lead to vision loss, but early diagnosis and treatment can go a long way toward protecting your eyesight.
This common eye disease is the leading cause of blindness in working-age adults. Diabetic retinopathy is caused when high blood sugar damages blood vessels in the retina (a light-sensitive layer of cells in the back of the eye). Damaged blood vessels can swell and leak, causing blurry vision or stopping blood flow. Sometimes new blood vessels grow, but they aren’t normal and can cause further vision problems. Diabetic retinopathy usually affects both eyes.
Risk Factors for Diabetic Retinopathy
Anyone with type 1, type 2, or gestational diabetes (diabetes while pregnant) can develop diabetic retinopathy. The longer you have diabetes, the more likely you are to develop it. These factors can also increase your risk:
- Blood sugar, blood pressure, and cholesterol levels that are too high.
- Race/ethnicity: African Americans, Hispanics/Latinos, and American Indians/Alaska Natives are at higher risk.
If you have diabetic retinopathy, low-vision aids such as magnifying glasses and special lenses can help. Ask your eye doctor to refer you to a low-vision specialist.
Stages of Diabetic Retinopathy
Diabetic retinopathy has 2 main stages:
Early stage (nonproliferative): Blood vessel walls in the retina weaken and bulge, forming tiny pouches (you won’t be able to detect them, but your eye doctor can). These pouches can leak blood and other fluid, which can cause a part of the retina called the macula to swell (macular edema) and distort your vision. Macular edema is the most common cause of blindness in people with diabetic retinopathy. About half of people with diabetic retinopathy will develop macular edema.
Advanced stage (proliferative): In this stage, the retina begins to grow new blood vessels. These new vessels are fragile and often bleed into the vitreous (the clear gel between the lens and retina). With minor bleeding, you may see a few dark spots that float in your vision. If there’s a lot of bleeding, your vision may be completely blocked.
You may not notice symptoms in the early stage. That’s why it’s very important to get a dilated eye exam at least once a year to catch any problems early when treatment is most effective.
Symptoms in the advanced stage can include:
- Blurry vision
- Spots or dark shapes in your vision (floaters)
- Trouble seeing colors
- Dark or empty areas in your vision
- Vision loss
How Diabetic Retinopathy Is Diagnosed
During your eye exam, your eye doctor will check how well you see the details of letters or symbols from a distance. Your doctor will also look at the retina and inside of your eyes and may use a dye to reveal leaky blood vessels. If it turns out you have diabetic retinopathy, your eye doctor may want to check your vision more often than once a year.
You should be checked for diabetic retinopathy immediately if you’re diagnosed with type 2 diabetes. If you have type 1 diabetes, you should be checked within 5 years of your diagnosis and then regularly thereafter, typically every year. The sooner you’re treated for diabetic retinopathy, the better that treatment will work.
Call your eye doctor if you notice changes in your vision, especially if they happen suddenly. Changes may include:
- Blind spots
- Difficulty reading or doing detail work
Diabetic Retinopathy Treatment
Treating diabetic retinopathy can repair damage to the eye and even prevent blindness in most people. Treatment can start before your sight is affected, which helps prevent vision loss. Options include:
- Laser therapy (also called laser photocoagulation). This creates a barrier of scar tissue that slows the growth of new blood vessels.
- Medicines called VEGF inhibitors, which can slow down or reverse diabetic retinopathy.
- Removing all or part of the vitreous (vitrectomy).
- Reattachment of the retina (for retinal detachment, a complication of diabetic retinopathy).
- Injection of medicines called corticosteroids.
Other Eye Diseases
A cataract is the clouding of the normally clear lens in your eye. Though everyone’s lenses tend to get cloudy as they get older, people with diabetes are more likely to have cataracts, and at a younger age. One reason is that high blood sugar can cause deposits to build up in the lenses and make them cloudy.
Other risk factors include high blood pressure, having obesity, too much sun exposure over time, and smoking.
Surgery is the only way to treat cataracts, but you usually don’t have to have surgery right away. Using brighter lights in your home and anti-glare sunglasses outside can help early on. If your cataracts get in the way of doing everyday activities, it may be time for surgery. The good news is the surgery is very safe, and most people have better vision afterwards!
Glaucoma is a group of eye diseases that damage the optic nerve, usually because of too much pressure in the eye. Many types of glaucoma don’t have symptoms, and vision loss can happen so slowly that you don’t notice it.
People with diabetes are twice as likely to develop open-angle glaucoma, the most common type. Other risk factors include having a family history of glaucoma, being over age 60, and being African American, Asian, or Hispanic/Latino.
Diabetes can also cause neovascular glaucoma. This happens sometimes with diabetic retinopathy when new and abnormal blood vessels grow on the iris (the colored part of the eye). The new vessels can block off the flow of fluid out of the eye, which raises eye pressure.
There isn’t a way to prevent glaucoma, but treatment can help stop it from getting worse. That’s why catching glaucoma early is so important. Treatment options include medicines, laser treatment, and surgery. Talk to your eye doctor about what choices are best for you.
Prevent or Delay Eye Diseases
You can protect your vision and lower your chance for vision loss with these steps:
- Get a dilated eye exam at least once a year so your eye doctor can spot any problems early when they’re most treatable.
- Keep your blood sugar levels in your target range as much as possible. Over time, high blood sugar not only damages blood vessels in your eyes, it can also affect the shape of your lenses and make your vision blurry.
- Keep your blood pressure and cholesterol levels in your target range to lower your risk for eye diseases and vision loss. Also good for your health in general!
- Quit smoking. Quitting lowers your risk for diabetes-related eye diseases and improves your health in many other ways too.
- Get active. Physical activity protects your eyes and helps you manage diabetes.
Get Your Eyes Checked
Eye problems are common in people with diabetes, but treatments can be very effective. Only your eye doctor can diagnose eye diseases, so make sure to get a dilated eye exam at least once a year. The earlier eye problems are found and treated, the better for your eyesight.