If diabetes is not well-controlled, chronic high blood sugar (blood glucose) levels will damage sensitive blood vessels in the retina. When these changes happen to enough of the blood vessels, the cells of the retina are deprived of their blood supply. In response to the lack of blood, new blood vessels grow. These new blood vessels are abnormal, fragile and often leak blood. Ultimately, this leads to blurry vision and vision damage.
Symptoms of diabetic retinopathy
Typically, there are no diabetic retinopathy symptoms. In some cases mild-to-severe blurring, seeing "strings," "cobwebs" or specks floating in your visual field, or vision loss may occur.
It's crucial to see an optometrist or an ophthalmologist every year for an eye examination. The types of vision tests you may have for diabetic retinopathy diagnosis include:
- Visual acuity test – The common eye chart test, which measures vision ability at various distances
- Pupil dilation – The pupil is widened with eye drops to allow a close-up examination of the eye's retina.
- Tonometry – In this standard test that measures the pressure inside of the eyes, a machine blows a small amount of air into the eye. The test may feel unusual, but it does not cause pain.
- Ophthalmoscopy – The doctor performs a detailed examination of the retina using a special magnifying glass.
Treatment and next steps
Diabetic retinopathy treatment depends on how your eyes are affected. Some people with retinopathy develop macular edema. This problem occurs when fluid leaks into the macula, the part of the eye needed for sharp, straight-ahead vision. The fluid causes the macula to swell, causing blurry vision.
Macular edema is treated with focal laser surgery, which cuts the risk for vision loss in half. The surgeon makes numerous tiny laser burns in leaky areas of the retina near the macula. These burns stave off further leaking. Surgery may be needed more than once.
Proliferative retinopathy is treated with scatter laser surgery. The surgeon makes 1,000 to 2,000 laser burns in areas of the retina farther away from the macula. The surgery may be done during two or more sessions. This treatment shrinks abnormal blood vessels. It’s helpful if the vessels haven’t started to bleed yet or are bleeding just a little. With proper treatment, people with proliferative retinopathy have a less than 10 percent chance of developing blindness within five years.
In both types of laser treatment, the eye is numbed with special drops before the surgery. The area behind the eye also may be numbed to prevent discomfort. It’s possible that you may feel a stinging sensation during the procedure.
The longer you have diabetes, the more likely you are to develop diabetic retinopathy. The following steps can help you preserve your sight:
- Keep your blood sugar (blood glucose) levels controlled. People who keep these levels closer to normal are less likely to have retinopathy.
- Control hypertension (high blood pressure), which can make eye problems worse. Consult with your provider for your ideal blood pressure reading.
- If you smoke, quit. Smoking is a risk factor for macular degeneration, which can lead to blindness.
Get a regular dilated eye exam at least once a year, even if you don't have vision problems. The exam should be by a doctor with experience in caring for people with diabetes.