Eyesight is something it’s easy to take for granted: It’s not until your vision is threatened that you start to realize just how important it is to you, or how scary the possibility of permanent damage is. For people diagnosed with diabetes, monitoring and preserving their eye health is another critical part of managing the condition.
“Since we know that eye disease is a big consequence of diabetes, and uncontrolled diabetes, patients need what’s called a dilated eye exam,” says Paul Knoepflmacher, MD, a clinical instructor in medicine at The Mount Sinai Hospital.
These exams, which you should get at least once a year, can detect a variety of eye problems associated with diabetes. Here are some of the health problems that may impact vision, according to Minisha Sood, MD, an endocrinologist in New York City:
Retinopathy: damage to the blood vessels of the retina
Macular edema: swelling in the macula part of the retina
Glaucoma: damage to the optic nerve, which connects the eye to the brain
Cataracts: clouding of the eye’s lens
Each of these issues can cause severe vision loss and possibly blindness, according to the National Eye Institute (NEI).
Among people with diabetes, retinopathy is the most common cause of vision loss. The back of the eye—the retina—takes in light from the cornea and pupil and converts it into images for the brain to decode, according to the American Diabetes Association (ADA). The retina contains small blood vessels; damage to the blood vessels from sustained high blood sugar levels can make them become blocked or closed off.
If you are experiencing retinopathy, you may notice these symptoms, according to Dr. Sood.
Temporary vision loss
Loss of color vision
Seeing your eye doctor regularly is crucial, however; not all cases of diabetic retinopathy have obvious symptoms. “You may have significant diabetic retinopathy, yet you may have no symptoms whatsoever,” according to Marc Werner, MD, ophthalmologist in Manhattan and Long Island. “[If] you’ve had diabetes for 10 years [and] you think your vision is fine, that’s not a reason not to see the eye doctor.”
A formal and thorough dilated eye exam is the only way to be diagnosed with diabetic retinopathy, says Dr. Werner.
The macula is a part of the retina that specializes in fine, extra-sharp details, according to the ADA. “Diabetic macular edema is a situation that occurs once someone has diabetic retinopathy,” says Dr. Sood. “If the macula has bleeding within it from an abnormal blood vessel that was there because of retinopathy, that can impair vision.”
Blocked blood vessels in and near the eye put a lot of pressure on the eyeball. Over time, this can damage the optic nerve, which connects and transmits signals between the eye and the brain. With glaucoma, peripheral vision becomes blurry or lost first; all vision may be lost eventually. People with diabetes have twice the risk of developing glaucoma as those without diabetes, according to NEI.
Taking Care of Your Vision
To prevent vision loss from diabetes, regular checkups are crucial. “Whether it’s type 1 or type 2 [diabetes], you at least need an annual eye exam to make sure nothing bad is going on in the back of the eye,” says Dr. Werner. (Learn more about the recommended medical care routine for type 2 diabetes here.)
That said, don’t wait for your next appointment if you notice any new or troubling symptoms: “Should you notice any change in your vision at any time, don’t wait for that annual eye exam,” says Dr. Werner. “Get right into the office.”
The severe complications from diabetes—blindness, kidney failure, amputations, to name a few—can be scary. However, strong diabetes management and good glycemic control can prevent most of them. In fact, 90 percent of vision loss from diabetes is preventable, according to the Centers for Disease Control and Prevention, and early treatment plays a big role.
“Every percentage that you can reduce your A1C level confers a significantly reduced risk of developing eye disease,” says Dr. Sood. Managing blood pressure can also reduce the risk of retinopathy and other eye conditions, according to ADA. (Learn the link between diabetes and heart disease here.)
The health of your eyes can also be a good gauge of your overall diabetes control. When examining the eyes, your eye doctor can get a good look at the blood vessels in the back of the eye. “If the blood vessels are looking good in the back of your eye,” says Dr. Werner, “you have an excellent chance that they’re working everywhere in your body and that you’re managing your diabetes very well.”