Diabetes is a complex condition that can impact different parts of the body, including the eyes. Diabetic retinopathy is a common complication of diabetes and is the leading cause of blindness in working-age adults. Focus spoke with Mass Eye and Ear retina specialist Leo Kim, MD, PhD, about diabetic retinopathy and how to prevent it.
What is diabetic retinopathy?
Diabetic retinopathy is a common complication of both Type 1 and 2 diabetes that occurs when a person’s blood vessels are damaged from persistent high blood sugar. Elevated blood sugar over time will cause damage to your retina (the part of your eye that detects light and sends signals to your brain) and cause problems with your vision.
Diabetic retinopathy is incredibly common, with 15 percent of patients in the U.S. with diabetes developing the retinal disease. It’s also the leading cause of blindness in working-age adults.
What are the most common symptoms and risk factors for developing diabetic retinopathy?
The most common symptoms of diabetic retinopathy are blurry and distorted vision, floaters and dark areas of vision, which occurs from swelling of the macula (a part of the retina that processes what you see directly in front of you).
There are a variety of risk factors for developing the disease. How long a person has had diabetes, poor glucose control, high cholesterol and high blood pressure have all been associated with higher risk for developing diabetic retinopathy. Another important risk factor for women is pregnancy, which can increase the risk of diabetic retinopathy progressing.
Are their different types of diabetic retinopathy?
There are various types and stages of diabetic retinopathy, from mild to moderate non-proliferative and severe non-proliferative diabetic retinopathy, to proliferative diabetic retinopathy. Non-proliferative diabetic retinopathy is an early stage of the disease where there are mild or no symptoms. Proliferative diabetic retinopathy is a more serious, advanced stage where the growth of abnormal blood vessels occurs within the eye, which can lead to bleeding inside the eye as well as retinal detachment.
How is diabetic retinopathy treated?
The swelling of the macula, which we call diabetic macular edema, can be treated with anti-VEGF (anti-vascular endothelial growth factor) drugs that can be injected into the eye. Anti-VEGF drugs can decrease the bleeding inside the eye and prevent abnormal blood vessels from forming. However, these injections are not a cure for diabetic retinopathy, though some research evidence suggests anti-VEGF drugs can improve the severity of diabetic retinopathy.
Other drugs that may be used to treat macular edema are steroid drugs. Other less frequently used methods include laser treatment of the abnormal blood vessels to decrease leakage from macular edema. For patients with a hemorrhage inside the eye from proliferative diabetic retinopathy, we use anti-VEGF drugs to stop the growth of the abnormal blood vessels. Ultimately, if the blood inside the eye does not clear, or if there is a retinal detachment, a patient may need surgery.
If a person has diabetes, should they be monitored for diabetic retinopathy?
A person with any type of diabetes should absolutely be monitored for diabetic retinopathy. The frequency of the monitoring is based on the severity of the diabetic retinopathy. For example, if you have no diabetic retinopathy, then you may have follow-up appointments with an ophthalmologist every one to two years. If you do have the disease, we like to see these patients for follow-ups more frequently.
Diabetic retinopathy can be prevented by maintaining good control of your diabetes, as well as your cholesterol and blood pressure.
Are there any new treatments in the works to treat diabetic retinopathy?
Yes, there are new treatments on the horizon for the disease. Recently, a drug targeting both VEGF and Ang2 (two proteins that stimulate the development of new blood vessels) was approved for the treatment of wet age-related macular degeneration, and studies are under way to evaluate this dual target approach for diabetic retinopathy. There are also new methods to extend delivery of anti-VEGF drugs inside the eye, including the port delivery system, which is a device implanted inside the eye that continuously delivers the anti-VEGF drugs for an extended period.
There are also several new drug treatments in development. Here at Mass Eye and Ear, my team and I are developing RUNX1 (runt-related transcription factor 1 protein) inhibitors as a new class of drugs for the treatment of diabetic retinopathy that also prevent the unwanted formation of new blood vessels in the eye.