High blood sugar levels due to diabetes can affect your eyes. Over time, too much blood sugar can damage tiny blood vessels in the retina, which is the part of your eye that detects light. As a result, these blood vessels may swell and leak, which results in diabetic retinopathy, one of the most common causes of blindness in the United States among people with diabetes. Early diagnosis and treatment can prevent additional damage to the retinas and help you avoid vision loss from diabetic retinopathy.
Typically affecting both eyes, diabetic retinopathy occurs in two stages. The early stage is called nonproliferative diabetic retinopathy (NPDR). This is when tiny blood vessels swell and leak blood and other fluids. Many people don’t have signs of diabetic retinopathy at this stage, but some experience blurry vision.
The more advanced form of this condition is proliferative diabetic retinopathy (PDR). If you have PDR, your retina grows new blood vessels to compensate for the damaged ones. However, these weak, new blood vessels can leak blood into a substance called the vitreous between the lens and retina. PDR may cause:
- Blank or dark areas in your field of vision
- Blurry vision that may come and go
- Cobweb-like streaks in your field of vision
- Difficulty seeing colors
- Difficulty seeing at night
- Floaters, or spots, that seem to float in your field of vision
- Vision loss
Diabetic retinopathy occurs due to high blood sugar from diabetes. If you have type 1 or type 2 diabetes, you’re at risk of developing diabetic retinopathy. Your risk increases the longer you have diabetes. It also goes up if your diabetes is poorly managed and your blood sugar is consistently high.
In addition to high blood sugar, other factors can increase your risk of diabetic retinopathy, including:
- Being African American, Hispanic or American Indian/Alaska Native
- High blood pressure
- High cholesterol
Not every case of diabetic retinopathy is preventable, but these steps can help you reduce your risk:
- Keep diabetes under control. The higher your blood sugar gets, the greater your risk of diabetic retinopathy. Work with your primary care provider to create a plan to stay within a target blood sugar range. Your plan will likely include taking medications or insulin to treat diabetes, exercising regularly and following a healthy diet.
- Manage high blood pressure and high cholesterol. These conditions increase your risk for diabetic retinopathy. Your provider can help you manage them. Fortunately, many of the healthy lifestyle choices that can help control diabetes can also aid in managing high blood pressure and high cholesterol.
- Quit smoking. Kicking the habit can lower your diabetic retinopathy risk.
- Stay on top of your eye health. Tell your provider or ophthalmologist about any new vision symptoms, and see your ophthalmologist annually for a dilated eye exam. These steps won’t eliminate your risk for diabetic retinopathy, but if you’re diagnosed with it, they may help you avoid extensive damage.
If diagnosed too late or left untreated, diabetic retinopathy can cause serious complications, including:
- Diabetic macular edema. When blood vessels in the retina leak, fluid can enter the macula, an area near the center of the retina that allows you to see objects straight ahead. Fluid in the macula can cause blurry vision.
- Neovascular glaucoma. New vessels that develop in the eye and prevent fluid from draining from the eye can damage the optic nerve, causing neurovascular glaucoma. This condition can lead to blindness.
- Retinal detachment. PDR causes new blood vessels to form, and when this happens, scar tissue may follow. This scar tissue can lead the retina to separate from the back of the eye, which is known as a detached retina. This may lead to blindness.