People with diabetes are at a higher risk for conditions that cause vision loss or blindness than other people, according to the American Diabetes Association (ADA). If you have diabetes, you can take steps to reduce your risk for vision loss or blindness.
Diabetes can cause the following eye disorders:
Diabetic retinopathy is damage to the retina, the light sensitive area at the back of the eye. The damage is caused by changes in the blood vessels that supply the cells of the retina with oxygen and nutrition. In the first stage of retinopathy, called background or nonproliferative retinopathy, the blood vessels develop small balloon-like swellings called microaneurysms that can leak fluid and blood, or become clogged. When these changes happen to enough of the blood vessels, the cells of the retina are deprived of their blood supply. In response to the lack of blood, new blood vessels grow. These new blood vessels are abnormal, fragile, and often leak blood. The result is loss of vision or blindness. This phase is called proliferative retinopathy. Usually, diabetic retinopathy progresses from nonproliferative to proliferative over a period of years. Typically, there are no symptoms of diabetic retinopathy. In some cases mild-to-severe blurring, seeing "strings," "cobwebs" or specks floating in your visual field, or vision loss may be symptoms. Retinopathy can be treated with photocoagulation, a special laser treatment that stops blood leakage and shrinks blood vessels.
During the changes in the blood vessels in nonproliferative retinopathy, macular edema can occur when fluid leaks into the part of the eye where focusing occurs, the macula. The macula swells with fluid causing vision to blur and can be lost entirely. Although nonproliferative retinopathy usually does not require treatment, macular edema must be treated. Fortunately treatment is usually effective stopping and sometimes reversing the vision loss.
Your retina can be badly damaged before you notice any change in vision, and most people with nonproliferative retinopathy have no symptoms, the ADA says. Even with proliferative retinopathy, people sometimes have no symptoms until it's too late to treat the condition. That's why it's crucial for people with diabetes to see an eye care professional every year for eye exams.
Diabetes can also lead to glaucoma. Glaucoma is a condition in which the optic nerve becomes damaged, leading to vision loss. It is caused by a poorly understood group of disorders. Most, but not all, of these diseases cause an increase in intraocular pressure, or pressure inside the eye ball. People with diabetes are more likely to suffer from glaucoma than people without diabetes, according to the ADA. The longer a person has diabetes, the greater the risk for glaucoma. The risk for glaucoma also increases with age. Usually, the damage to the optic nerve that occurs with glaucoma does not cause symptoms. High intraocular pressure can be treated with medicine, usually eye drops, to prevent damage to the optic nerve.
A cataract is a clouding of the lens of the eye. People who have diabetes are more likely to develop this condition than people who don't have diabetes. People with diabetes are also more likely to develop cataracts at a younger age, the ADA says. Cataracts in someone with diabetes tend to progress more quickly than in someone without diabetes. Symptoms of a cataract are blurry vision and glare from oncoming headlights at night. If cataracts are severe enough to interfere with vision, they can be treated with surgery.
The longer you have diabetes, the more likely you are to develop eye disease. The following steps can help you preserve your sight:
Keep your blood sugar levels under tight control. People who keep these levels closer to normal are less likely to have retinopathy.
Control high blood pressure as well as high cholesterol levels, which can make eye problems worse. Consult with your provider for your ideal blood pressure reading and ideal cholesterol levels.
If you smoke, quit.
Get a regular dilated eye exam at least once a year, even if you don't have vision problems. The exam should be by a doctor with experience in the care of people with diabetes.
These are reasons to see your eye care professional right away:
Your vision becomes blurry.
You have trouble reading signs or books.
You see double.
One or both of your eyes hurt.
Your eyes get red and stay that way.
You feel pressure in your eyes.
You see spots or floaters.
Straight lines don't look straight.
Your side (peripheral) vision deteriorates.
You have any sudden change in your vision.
You have had type 1 diabetes for five or more years and have not had a dilated eye exam.
You have type 2 diabetes and have not had a dilated eye exam.
You're going through puberty and you have diabetes.
You're planning to become pregnant and you have diabetes.