Diabetic retinopathy is an eye disease that can lead to vision loss and sometimes blindness in people with diabetes. Managing blood sugar and getting regular eye exams can help reduce your risk of developing DR. Detecting and preventing DR early is key to preserving your vision and eye health.
Q: What is diabetic retinopathy?
A: Diabetic retinopathy (DR) is a preventable eye disease that people with diabetes—both type 1 and type 2—are at risk of developing over time. DR can cause vision problems and is the leading cause of blindness in diabetic adults. DR occurs when blood vessels in the light-sensitive tissue in the back of the eye, called the retina, are damaged. Many patients with potentially vision-threatening DR don't have symptoms and could benefit from early treatment, therefore it is important that patient with diabetes get screening eye examinations regularly.
There are two types of DR:
- Non-proliferative DR–The most common type occurs when the walls of your blood vessels are weakened by high blood sugar. It may cause retinal swelling and mild-moderate vision loss, but it can usually be effectively treated.
- Proliferative DR–This is a more serious type of DR where damaged blood vessels no longer work and new, irregular blood vessels are produced. The abnormal blood vessels can threaten your vision because they can cause bleeding in the eye or even lead to a more serious problem called a retinal detachment. These complications can sometimes lead to severe vision loss or even blindness.
Q: What causes DR?
A: Over time, uncontrolled and high blood sugar can damage the blood vessels in the retina. Too much sugar in your blood damages the lining of blood vessels, leading to fluid leakage from the damaged vessels as well as loss of blood supply to the retina. The fluid leakage can cause swelling in the retina, which tends to happen in the middle part of the retina, called the macula. This swelling in the macula is called macular edema, which is the most common cause of vision loss related to DR. If the damage to the blood vessels in the retina is more severe, your eye tries to make up for the loss by developing new blood vessels. These new abnormal blood vessels cause problems because they are fragile and can bleed easily. Sometimes, these abnormal vessels can also cause traction or pulling on the retina, which can cause the retina to detach from the wall of the eye (retinal detachment). This can be a potentially devastating complication that often requires surgery and can sometimes lead to severe vision loss.
Q: What are the symptoms?
A: DR can range from very mild to very advanced. No matter what the stage of the DR is, there are often no symptoms at first, which is why it's important for people to get regular eye screenings. Catching and treating DR in earlier stages can help prevent vision loss.
Signs of DR include the following:
- Blurry vision
- Specks or strings, called floaters, in your vision
- Distortion of the vision
- Poor night vision
- Blank or dark areas in your vision
Q: Who's at risk?
A: Anyone with type 1, type 2 and gestational diabetes (diabetes occurring in pregnancy) is at risk for developing DR. DR is the leading cause of blindness in working-age adults aged 18-64, and it's a growing concern among even younger people. The longer someone has diabetes, the greater the risk of developing DR. DR rates are higher for Blacks, Hispanics, Native Americans and Alaskans than whites.
Factors that can influence DR severity include:
- Blood sugar control
- High blood pressure
- High cholesterol
- Pregnancy
- Smoking
- Other diseases that affect the blood or blood vessels (e.g. anemia)
Q: How's is diabetic retinopathy treated?
A: There are vision-saving treatments available for DR. Your doctor will recommend the treatment path that is right for you based on your health history, symptoms and stage of DR. Treatments include:
- Laser surgery– An in-office procedure that shrinks or seals leaking or abnormal blood vessels.
- Injections–Medication is injected into the eye to stop leaking or growth of blood vessels.
- Vitrectomy–Surgery to repair or reverse damage to your retina caused by DR.
Q: How will my eye doctor check for DR?
A: Several screening tests are available for signs of DR. A simple vision check and dilated eye exam is the most common test for eye diseases. During the painless exam, your eye doctor checks your vision on the eye chart, and will then dilate your pupils using drops to examine your eyes and look at the retina and blood vessels in the back of the eye. Eye exams are often the only way to know if there are any retina problems since you may not have signs or symptoms.
Other imaging tests can be helpful to examine the retina and are often done in conjunction with an eye exam. Common imaging tests of the retina include the following:
- Fundus photography: This involves taking a photograph of the retina with a special camera.
- Optical coherence tomography: This is another non-invasive imaging tool which is able to get high resolution scans of the macula, the center part of the retina. The macula can often be affected by DR, and macular swelling (edema) can easily be detected using this imaging tool.
- Fluorescein angiography: This test may be necessary to evaluate the extent of damage to the blood vessels in the retina. It involves an injection of a special mineral-based dye (fluorescein) in a vein in the arm, and then taking a series of special pictures of the retina.
Some types of cameras are able to take photographs of the retina without dilating the eyes, and these cameras are more and more commonly being used to screen for DR without needing to have a full eye exam. Such cameras may be available at your primary care or diabetic care clinic. The images that are taken are read by the software or by a remote physician, and if DR is detected then you would be referred for an eye exam. It is important to note that a dilated eye exam is still the most accurate way to evaluate the eye for DR.
Typically, we recommend that diabetic patients have yearly eye exams. If you are diagnosed with DR, and depending on the DR severity, your doctor may want to see you more often to monitor you more closely for disease progression. Timely treatment of certain retinal problems can slow or stop the progression of those problems, which can help limit or reverse vision loss.
Q: How can you protect your vision?
A: The two ways to protect your vision are through health control and having regular eye exams to ensure early diagnosis and treatment of diabetic retinopathy. If you have other risk factors, such as high cholesterol or high blood pressure, there may be additional risk of vision loss as well as other complications from diabetes. With good control of blood sugar and other risk factors, which includes a healthy diet and regular exercise, the progression of retinal damage can be stopped and may even slowly be reversed.
