What Is Diabetic Retinopathy

There are plenty of complications that can arise from diabetes, but one you may not have considered is diabetic retinopathy. Without regular screening, diabetic retinopathycan lead to blindness.

“Diabetic retinopathy is an eye disease that affects the tissues in the back of the eye – called the retina – which process light and vision for the brain,” says Dr. Nancy Kunjukunju, a retina specialist at Krieger Eye Institute at LifeBridge Health in Baltimore. “High blood sugar levels can cause the retinal blood vessels to leak, swell, grow abnormally or be blocked. If that happens, the lack of normal blood and oxygen flow can cause a loss of tissue function that seriously affects vision.”

Among people who have had Type 1 diabetes for five years, 25 percent will develop diabetic retinopathy, Kunjukunju says. That number shoots up to 60 percent after 10 years. The numbers vary a bit more when you have Type 2 diabetes, but 53 percent of people who have had Type 2 diabetes for more than 10 years develop the disease. Many people with diabetic retinopathy are not aware that they have it, says Dr. Gregory Dodell, an assistant clinical professor of medicine, endocrinology, diabetes and bone disease at the Icahn School of Medicine at Mt. Sinai in New York.

The risk for diabetic retinopathy increases as you get older. You’re also at higher risk if you smoke. Of course, elevated blood sugar over an extended period leads to a higher risk for diabetic retinopathy as well.

“Other factors may also be high blood pressure, high cholesterol and kidney disease,” Kunjukunju says. “All of the different components of the body work together so when anything affects our blood vessels, including heart disease, our eyes can also be affected.”

A recently published study found a link between obstructive sleep apnea and diabetic retinopathy in patients who have Type 2 diabetes. However, when those patientsreceived continuous positive airway pressure treatment, or CPAP, they were less likely to develop retinopathy.

Having poor vision that makes you wear glasses or contacts has no connection to the development of diabetic retinopathy.

Many times, diabetic retinopathy has no symptoms until it’s too late – and that’s why regular eye exams are so important. “If diabetic retinopathy is not treated, symptoms can worsen, and eventually an individual may become blind,” Kunjukunju says.

Other times, symptoms like blurred vision, loss of color vision and floaters can occur. Other symptoms include spots, bleeding in the eye and an inability to see from the center of the eye. That’s the kind of vision you use when you are driving or reading, says Dr. Mark Goldfarb, an ophthalmologist with Advanced Eye Care in River Edge, New Jersey. If you haven’t already seen an eye doctor, make sure to do so when you have these kinds of symptoms.

The American Diabetes Association recommends that adults with Type 1 diabetes have an eye exam within five years of diabetes onset; people with Type 2 diabetes should have an exam at the time of diagnosis. Although someone with Type 2 diabetes may be newly diagnosed, that person could have been living with diabetes for as little as a month or as long as several years. That’s why an eye exam right after a diabetesdiagnosis is so important.

Even women who have diabetes and get pregnant or those who develop gestational diabetes while pregnant should be screened, Goldfarb recommends.

Although guidelines aren’t as clear on how often to return for an eye exam, Goldfarb generally advises returning once a year – although that will become more frequent if you’re diagnosed with diabetic retinopathy.

“I aim to ask patients during every office visit when their last ophthalmology evaluation was,” Dodell says. “Ideally, the ophthalmologist should be sending a note to the endocrinologist or primary care doctor regarding the office visit.”

During an exam for diabetic retinopathy, your eye doctor will dilate your eyes to see the back of the eye (the retina). He or she will look for abnormalities like swelling or the leaking or closing off of blood vessels. There are also newer imaging devices, like optical coherence tomography, that help eye doctors better view the back of your eye, Goldfarb says. These exams are also important to check for other eye problems that are more common when you have diabetes, such as glaucoma and cataracts.

When you see your eye doctor, be ready to share some of your recent blood sugar readings, Goldfarb says. This information can be helpful.

If you’re diagnosed with diabetic retinopathy, your eye doctor may tell you that you have nonproliferative diabetic retinopathy – which is an earlier stage of the disease – or proliferative diabetic retinopathy. With the latter, blood vessels become so damaged they close off, according to the American Diabetes Association. Then, newer but weaker blood vessels grow and leak blood, which can block your vision and potentially lead to the growth of scar tissue. Proliferative diabetic retinopathy can also lead to something called retinal detachment, and that can cause permanent vision loss, Goldfarb says.

Diabetic macular edema is a condition that can also develop when you have diabetic retinopathy. It involves swelling in the macula of the eye, according to the American Academy of Ophthalmology.

Treatment for diabetic retinopathy is most effective when it’s started early. Your eye doctor may perform laser treatments on the retinal blood vessels to help stop them from bleeding and leaking and to reduce swelling. There are also injections that can be made in the eye to slow or stop tissue damage.

Because many patients do not see an eye doctor regularly, there are efforts underway to increase the use of telemedicine to screen more patients for diabetic retinopathy. “This is fantastic, and I suspect will lead to better outcomes for patients,” Dodell says. However, telemedicine screenings can’t replace a full eye exam, Goldfarb believes.

The best way to reduce your risk for diabetic retinopathy is to keep your blood sugar under control and follow other healthy habits, like eating a balanced diet, exercising, not smoking and using your medications as prescribed. “If blood sugar levels are close to normal, an individual is less likely to be at risk,” Kunjukunju says.