Diabetic Retinopathy Prevention
If you have diabetes, you can take steps to prevent diabetic retinopathy from developing or to slow its progression. Precautions include getting regular eye examinations and keeping your blood glucose and blood pressure under tight control. Blood glucose levels are well controlled when levels of hemoglobin A1c (used to measure blood glucose levels over time) are less than 7%. Individuals with diabetes should keep their blood pressure below 130/80 mm Hg.
Two large studies have proven the benefits of controlling blood glucose levels when it comes to eye health. In the Diabetes Control and Complications Trial, people with type 1 diabetes who gave themselves multiple insulin injections daily to attain a hemoglobin A1c level of 7% reduced their risk of developing diabetic retinopathy by 76% compared with those who followed a less rigorous treatment regimen.
In addition, individuals who achieved the 7% A1c hemoglobin level reduced by more than half the likelihood of their condition would get worse.
In the United Kingdom Prospective Diabetes Study, people with type 2 diabetes maintaining a hemoglobin A1c level of 9% who controlled their blood glucose levels with medication were 30% less likely to have retinopathy that required laser treatment than people who relied on diet and exercise alone.
When it comes to lowering blood pressure, a study found that every 10-mm-Hg reduction in systolic blood pressure (the top number) decreased the incidence of retinopathy and other diabetic complications by 12%. Reducing blood pressure may even help individuals with diabetes who don't have high blood pressure. In a study of people with type 2 diabetes whose blood pressure was below 140/90 mm Hg, lowering blood pressure with medication to about 128/75 mm Hg resulted in less progression of diabetic retinopathy over a five-year period than in people whose blood pressure averaged 137/81 mm Hg.
Research also suggests that lowering blood cholesterol levels and quitting smoking may help to prevent diabetic retinopathy or at least slow its progression.