The US Centers for Disease Control and Prevention (CDC) reports that more than 100 million adults in this country are living with diabetes or prediabetes. Of those, 30.3 million – that’s 9.4 percent of the US population – have full-blown diabetes.
Another 84.1 million US adults have prediabetes. That’s a condition that, if left untreated, can lead to type 2 diabetes within five years. More than a third of adult Americans has prediabetes, and most of them don’t know they have it.
Why should we take note of these figures? Because consistently high blood glucose (sugar) levels, the hallmark of uncontrolled diabetes, can cause serious injury to your body’s nerves and blood vessels, impairing circulation and damaging your heart, liver, brain cells and eyes.
Most serious eye diseases related to diabetes begin when high blood glucose damages the eye’s tiny blood vessels. The four main eye diseases that can threaten the vision of a person with diabetes are diabetic retinopathy, diabetic macular edema, glaucoma and cataracts.
Diabetic retinopathy is the most common cause of vision loss for people with diabetes and the leading cause of blindness for all adults in the US. It occurs when high glucose blocks the tiny blood vessels that nourish the retina, the part of your eye that detects light and sends signals to your brain. These damaged blood vessels can begin to swell and leak fluid. This stage is called non-proliferative diabetic retinopathy.
In some cases, non-proliferative diabetic retinopathy progresses into the proliferative stage. That’s when the eye grows new blood vessels to make up for the blocked vessels in a process called neovascularization. But the newly formed blood vessels are highly unstable and leak and bleed easily.
These leaking blood vessels may even hemorrhage into the jelly-like material that fills the center of your eyes, called the vitreous. Blood in the vitreous results in dark spots that can block vision.
Diabetic retinopathy can also cause scar tissue to form in the back of your eye, which may pull the retina away from the back of the eye. This is called a retinal detachment, and it’s a serious complication that can cause loss of vision if not repaired quickly.
As the unstable blood vessels in your retina continue to bleed, they eventually cause the macula, the area of the retina that enables you to read, drive and see faces, to swell. This condition is called diabetic macular edema. Over time, this condition can destroy your sharp vision and lead to partial vision loss and eventually blindness.
The natural lenses of your eyes are clear structures that provide sharp vision. But over time, they can become cloudy, a condition called cataracts. People who have diabetes can develop cataracts at an earlier age than people without the disease, and people with diabetes are two to five times more likely to develop cataracts. It’s believed that high glucose levels cause protein deposits to build up on the lenses, leading to the cataracts.
Sometimes, blood from the leaking vessels blocks the normal drainage channels for fluid in the eyes. As a result, fluid builds up and pressure in the eye increases, which can damage the optic nerve and affect vision. Glaucoma is a group of eye diseases related to increased eye pressure. Having diabetes nearly doubles your risk of developing a type of glaucoma called open-angle glaucoma.
The best way to prevent vision loss from these eye diseases is to control your blood glucose levels and get regular exams by your eye doctor to look for swelling and changes in the blood vessels in your eyes.
To help control your diabetes, eat a healthy and balanced diet, exercise regularly and maintain a healthy body weight. High blood pressure and high cholesterol can affect your blood glucose level, so take all medications your doctor prescribes for these conditions and get them checked regularly. Don’t smoke and drink alcohol in moderation.
Regular eye exams can help find problems early, when they’re easier to treat. Early detection can save your vision. See you eye doctor yearly or as often as your doctor recommends. Call your eye doctor right away if you experience any of the following symptoms:
- Black spots in your vision
- Flashes of light
- “Holes” in your vision
- Blurred vision