What Is Diabetic Retinopathy?
Diabetic retinopathy is a condition in which the retina becomes damaged in people with diabetes. Risk factors for developing diabetic retinopathy include high blood sugars, high blood pressure, abnormal cholesterol levels, genetic factors, undergoing cataract surgery, puberty, and pregnancy.
Early diabetic retinopathy does not cause any symptoms. Advanced diabetic retinopathy may cause blurred vision, floaters, or a "curtain" over the vision.
The diagnosis is made with a dilated eye exam by a trained eye doctor.
Treatment options include laser treatment, eye surgery, and medications injected into the eye. Prevention involves controlling blood sugar and blood pressure and undergoing regular eye exams.
You should visit your primary care physician within a few days to discuss your symptoms.
How common is Diabetic Retinopathy?
Diabetic Retinopathy is also known as
- Diabetic eye disease
- Diabetic macular edema
Diabetic Retinopathy Symptoms
Most people with diabetic retinopathy will not develop any symptoms until the disease is very advanced. Therefore, screening and prevention are important parts of management for diabetic retinopathy. Symptoms you may develop during the late stages of diabetic retinopathy include:
- Blurred vision: People with diabetic retinopathy may develop blurred vision if they develop a complication of diabetic retinopathy known as macular edema, which is when fluid leaks behind the center of the retina responsible for central vision.
- Floaters: Some people with diabetic retinopathy may notice a sudden onset of new floaters, which are seen as "wisps" in their vision. This can occur if diabetic retinopathy causes bleeding into the jelly-like substance that fills the eyeball.
- Seeing a dark curtain fall over their vision: Some people with diabetic retinopathy may notice a dark curtain falling over part of their vision. This may be a sign that part of the retina is detaching. This is a condition that may need to be treated emergently to prevent further vision loss.
Diabetic Retinopathy Causes
Diabetic retinopathy is a condition in which the retina, which is the "film" in the back of the eye responsible for vision, becomes damaged in people with diabetes. Diabetes is a medical condition involving abnormally high levels of sugar in the blood. There are two main types of diabetes: type 1 diabetes and type 2 diabetes. Both types of diabetes can lead to the development of diabetic retinopathy. Specific risk factors for the development and progression of diabetic retinopathy include high blood sugars and high blood pressure, as well as abnormal cholesterol levels, genetic factors, cataract surgery, and undergoing puberty or becoming pregnant.
The main cause of diabetic retinopathy is high blood sugar, with high blood pressure (hypertension) as another predominant cause.
- High blood sugar: High levels of blood sugar over time can damage the cells and blood vessels in the retina, leading to diabetic retinopathy. The level of blood sugar control in people with diabetes is normally measured with a lab test called hemoglobin A1c (HbA1c). Studies have shown that reducing the HbA1c level by one percent is associated with an approximately 35 percent reduction in the risk of developing diabetic retinopathy .
- High blood pressure: Reducing the systolic blood pressure (the "top" number) by 10 mmHg is associated with an approximately 40 to 50 percent reduction in progression of diabetic retinopathy .
Other causes that may also lead to the development of diabetic retinopathy include the following.
- Abnormal cholesterol levels: This factor has not been consistently demonstrated in all studies, however.
- Genetic factors: For example, among people with type 1 diabetes, there is a 25 to 50 percent heritability of developing severe diabetic retinopathy .
- Cataract surgery
- Undergoing puberty or becoming pregnant: The reason for these risks is unclear but may have to do with fluctuating blood sugar levels or other systemic factors.
Treatment Options and Prevention for Diabetic Retinopathy
Diabetic retinopathy is a long-term condition that requires continuous monitoring and treatment to improve outcomes. Early diabetic retinopathy is usually monitored without treatment. Advanced diabetic retinopathy can be treated with laser treatment, eye surgery, and/or medications injected into the eye.
People with advanced diabetic retinopathy may benefit from a laser procedure called panretinal photocoagulation. In this procedure, a special laser is used to treat the retina to stop abnormal blood vessels from growing and leaking. This treatment does not restore vision but may reduce the risk of developing further vision loss. People with advanced diabetic retinopathy who receive laser treatment saw a 50 percent reduction in the risk of developing severe vision loss .
In addition, people with diabetic retinopathy who develop a complication known as macular edema may benefit from a laser procedure called focal laser photocoagulation, in which a special laser is used to treat the center of the retina to reduce the swelling.
Some people with advanced diabetic retinopathy that causes bleeding into the eye or a detachment of the retina may need to undergo an eye surgery called vitrectomy. In this surgery, the "jelly" that fills the eye is removed along with any blood in the eye, and areas of the retina are treated with a laser to repair the detached retina and prevent further vision loss.
Medications injected into the eye
Those with diabetic retinopathy who develop a complication called macular edema may benefit from medications injected into the eye.
- Anti-vascular endothelial growth factor (VEGF): These are the most commonly used medications, which include ranibizumab (Lucentis), bevacizumab (Avastin), aflibercept (Eylea), and pegaptanib (Macugen). These medications are injected in your physician's office with local anesthesia and often require repeated injections approximately once per month.
- Steroids: Less commonly, steroid medications such as triamcinolone (Triesence) can be injected into the eye to treat macular edema, but this is associated with more side effects.
Prevention is an important part of diabetic retinopathy management because most cases of diabetic retinopathy do not cause symptoms until they are advanced. Components of prevention include regular eye screenings and controlling blood sugar and blood pressure.
People with diabetes should undergo regular screening by an eye doctor, which involves the doctor dilating the pupil and looking in the back of the eye with a special lens. The recommended timing and frequency of screening varies based on the type of diabetes and severity of diabetic retinopathy.
- Type 1: Those with type 1 diabetes should begin screening within five years of being diagnosed with type 1 diabetes.
- Type 2: People with type 2 diabetes should begin screening at the time they are diagnosed with type 2 diabetes.
- Those who have already been diagnosed: Everyone with diabetes should be screened at least once a year if they have diabetic retinopathy, and more frequently if they have more severe diabetic retinopathy.
Controlling blood sugar with lifestyle changes and/or medications has a strong effect on reducing the development and progression of diabetic retinopathy. Studies have shown that strict control of blood sugar (with a target HbA1c level of <7%) can reduce the risk of developing diabetic retinopathy by 76 percent in type 1 diabetes  and by 21 percent in type 2 diabetes .
Controlling blood pressure with lifestyle changes and/or medications can also reduce the risk of developing diabetic retinopathy. Studies have shown that keeping blood pressure <150/85 mmHg reduced the risk of progression of diabetic retinopathy by about one-third in type 2 diabetes .
When to Seek Further Consultation for Diabetic Retinopathy
If you have either type 1 or type 2 diabetes, you should go see an eye doctor. He or she can examine the back of your eye and determine an appropriate screening and prevention plan for you.
If you develop any symptoms of diabetic retinopathy
You should see an eye doctor if you experience blurry vision, floaters, or a curtain over your vision. The doctor can examine your eye to determine if your symptoms are due to diabetic retinopathy or another cause and then offer the appropriate treatment.
Questions Your Doctor May Ask to Determine Diabetic Retinopathy
To diagnose this condition, your doctor would likely ask about the following symptoms and risk factors.
- How long has your current headache been going on?
- Any fever today or during the last week?
- Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
- How severe is your headache?
- Do you have a sore throat?
The above questions are also covered by our A.I. Health Assistant.
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