Let's begin by stating the obvious: The most important risk factor for diabetic retinopathy is simply having diabetes.
According to the U.S. Centers for Disease Control and Prevention (CDC), the number of adults diagnosed with diabetes nearly tripled between 1980 and 2007. In 2007, 1.5 million people in the United States were diagnosed with the disease, bringing the total to 24 million Americans living with diabetes.
Every person who has diabetes, whether it's type 1 or type 2, is at risk of developing retinopathy. The disease is more prevalent and tends to be more severe, though, among those with type 1 disease.
As with all chronic disorders, some risk factors lie outside your control. Others can be managed with lifestyle modifications and medical intervention.
Non-Modifiable Risk Factors
- Genetic variation. The abnormal development of new blood vessels that occurs in diabetic retinopathy is regulated by a protein called vascular endothelial growth factor A (VEGF-A). This protein carries out orders from a gene called, fittingly enough, the VEGF-A gene. Scientists have discovered a variation in the sequence of this gene that's associated with the development of severe diabetic retinopathy.
- Advancing age. Diabetic retinopathy is rare among children age 10 and younger. About 10 percent of teens with diabetes ages 15 to 19 have diabetic retinopathy. The proportion rises from 10 percent to 40 percent between ages 20 and 29. By age 30, about 60 percent of people with diabetes have diabetic retinopathy, and by age 45 the figure rises to 70 percent.
- Ethnicity. Diabetic retinopathy is more common among some ethnic groups than others. For example, African Americans and Latino Americans with type 2 diabetes have a greater prevalence and severity of the disease than non-Hispanic whites. Researchers have been unable to explain why Latino Americans are disproportionately affected. African Americans, though, tend to have more risk factors for diabetes and thus may develop diabetic retinopathy as a complication of the disease.
- Duration of diabetic disease and age at diagnosis. The longer you've had diabetes, the more likely you are to develop diabetic retinopathy.
- Severity of diabetic disease. The more severe your diabetes is, the more likely you are to have diabetic retinopathy and the more likely it is to threaten your vision.
- Gender. Men with diabetes are at higher risk for developing diabetic retinopathy and for having more severe retinal disease. Researchers continue to seek an explanation for this puzzling gender difference.
Controllable or Partially Controllable Risk Factors
- Poorly controlled blood sugar. Research indicates a direct correlation between the degree of blood sugar control and the likelihood of onset or progression of diabetic retinopathy.
- High blood pressure. If you've had diabetes for 10 years or longer and have high blood pressure, you're at risk for diabetic retinopathy that's more destructive and progresses more quickly.
- Obesity. Body mass index (BMI) is a measure of body weight adjusted for height. People with diabetes who are in the top quartile (that is, the highest 25 percent) of BMI compared with their peers are at twice the risk of developing retinopathy.
- Illness. People who have other health conditions, such as high blood pressure, heart disease, diabetic kidney disease, and high cholesterol, are at increased risk of developing diabetic retinopathy.
Reducing the risk of low vision during the early stages of diabetic retinopathy boils down to controlling modifiable risk factors. Here are some things you can do:
Learn about the disease and its symptoms.
Since symptoms may be absent or subtle during the early stages of diabetic retinopathy, everyone with diabetes should have a comprehensive dilated eye examination at least once a year (see Diagnosing Diabetic Retinopathy for specific screening recommendations). Of course, if you notice any flecks, spots, or blurs in your visual field, you should visit your vision care provider immediately. Symptoms can include the following:
- Blurry vision
- Halos or flashing lights
- Double vision
- Dark spots or floaters
- Pain or a sensation of pressure
- Diminished peripheral (side) vision
- Poor night vision
Have regular eye exams for screening, monitoring, or evaluation of new symptoms
Tightly control your blood sugar. Tight glucose control is the linchpin of both prevention and management of diabetic retinopathy. Management is aimed is slowing disease progression in order to preserve vision.
Keep blood pressure and cholesterol within a narrow range. Controlling your blood pressure will reduce your risk of low vision and confer cardiovascular and other health benefits at the same time.
Reduce body mass index by following healthy lifestyle recommendations.
Get moving! Aerobic physical activity doesn't have to involve leg warmers and Spandex. It just means you need to exercise at moderate intensity at least 2½ hours per week (see the 2008 Physical Activity Guidelines for Americans). Brisk walking, swimming, cycling, snowshoeing, or any other activity will do, as long as it's powered by you. The CDC offers a free BMI calculator you can use to check your BMI or monitor it as you get active and lose weight.
Stop smoking or don't start. Smoking has a deleterious effect on virtually every body system, and the eyes are no exception. The chemicals in tobacco are believed to keep your body from properly absorbing lutein, an antioxidant that helps shield the retina. An equally important consideration is that people with diabetes have a high risk of stroke and heart attack, and smoking markedly elevates that risk. If you're a smoker, speak with your doctor about your smoking cessation options.
- What is Diabetic Retinopathy?
- Symptoms of Diabetic Retinopathy
- Diagnosing Diabetic Retinopathy
- Treatment & Care of Diabetic Retinopathy
- Diabetes, Vision Loss, & You