When you learn you have diabetes, your to-do list can feel a lot longer. You might be exercising more often, making changes to your diet, starting a new medication or learning about monitoring your blood sugar.
Though it might feel overwhelming, there’s another thing you should add to your list: Get an eye exam.
While we often think about diabetes increasing the risk for heart disease, kidney disease and stroke, it’s important to remember the disease can damage your eyes as well. People with diabetes have a risk of blindness that is 25 times higher than people without diabetes, largely because of a condition called diabetic retinopathy, which is the leading cause of blindness in working-age adults.
UNC Health ophthalmologist and retina specialist J. Niklas Ulrich, MD, answered common questions about diabetic retinopathy.
What is diabetic retinopathy?
The retina, a layer of tissue located at the back of your eye, is responsible for converting light into electrical signals that the brain can use to understand what it’s seeing.
As with other parts of the body, the retina needs healthy blood flow to do its job. Uncontrolled diabetes restricts that blood flow and damages the blood vessels in the eye.
There are two stages of diabetic retinopathy: nonproliferative, or early, diabetic retinopathy, and proliferative.
“In the early stage, some blood vessels might be leaking or dying off, which causes some bleeding or swelling at the back of the eye,” Dr. Ulrich says. “In the proliferative stage, your eye responds to that lack of blood flow by trying to create new blood vessels, which are not as good or as strong. They tend to bleed and cause scar tissue.”
That bleeding can cause vision loss, and the scar tissue can cause the retina to detach, which means it will no longer be able to process images. The longer a retina is detached, the higher the risk of permanent vision loss.
How is diabetic retinopathy diagnosed?
Diabetic retinopathy can be diagnosed in its earliest stages with a dilated eye exam, which is why it’s important to start getting regular exams when you’re diagnosed with diabetes. During this exam, the doctor will put drops in your eye which will relax your pupil muscles; when the pupil widens, the doctor can see the structures at the back of the eye, including the retina and optic nerve.
“In the early stages, diabetic retinopathy is completely asymptomatic,” Dr. Ulrich says. “We can see the bleeding on the exam, but the patient won’t have noticed any changes.”
Symptoms in the later stages include blurry vision, trouble focusing your eye and floaters—dark shapes like spots or strings in your eye—but by the time these appear, there may be significant damage to the vessels.
Get a dilated eye exam at the time of your diabetes diagnosis so you have a baseline picture of the vessels around your eye; most people should then have an annual eye exam to check for any damage. While an in-person dilated eye exam is preferred, Dr. Ulrich says that some clinics offer retinal photography. With this method, a specialized camera is used to take a picture of the eye that can be sent to an ophthalmologist for review.
This option can help expand screening for diabetic retinopathy.
“Screening rates are a big issue,” Dr. Ulrich says. “Only about 50 percent of people with diabetes are getting regular eye exams and may only get one when their vision deteriorates.”
How is diabetic retinopathy treated?
When diabetic retinopathy is found early, you may be able to halt its progression and prevent future damage by keeping blood sugar controlled.
If there’s been significant damage to the blood vessels in the eye, there are treatments that can prevent vision loss.
“We treat bleeding and swelling with injections in the eye,” Dr. Ulrich says. “I know it sounds terrible, but it’s almost painless. We’re good at numbing the eye, and most people say that it’s over before they know it.”
These injections have to be done regularly at first—usually every one to three months—to continue to seal the blood vessels that could cause bleeding or swelling.
Laser treatments can also be used to close leaking blood vessels. These procedures, which last longer than the injections, can be done in your ophthalmologist’s office.
If these options don’t work, your doctor may recommend a surgery called a vitrectomy, which removes blood and scar tissue from the eye.
These treatments can slow the progression of diabetic retinopathy but are not considered a cure—you may need ongoing treatment and should work to keep your diabetes controlled.
Can I prevent diabetic retinopathy?
Diabetic retinopathy could affect as many as 16 million people with diabetes by 2050. While it’s important to understand that risk, there is good news, Dr. Ulrich says.
“If you can keep your diabetes well-controlled, as recommended by your physician, you can completely avoid this disease,” he says.
You also have a little bit of time to get your diabetes under control.
“These blood vessels are resilient, so it will take five to 10 years of uncontrolled blood sugars to cause retinal changes,” Dr. Ulrich says. “The longer the disease is uncontrolled, the higher the risk of diabetic retinopathy.”
If you’re feeling overwhelmed, Dr. Ulrich recommends working with your provider on identifying the small, manageable changes you can make to your lifestyle.
“Getting your blood sugar down even a little bit can be a huge improvement for the eye,” Dr. Ulrich says. “Do what you can. Take those little steps in the right direction, and they’ll make a huge difference over time.”
If you need help controlling diabetes, talk to your doctor. If you need a doctor, find one near you.