Diabetes can cause diabetic retinopathy, a serious eye condition that can cause vision loss and blindness. Diabetic retinopathy is a common condition that affects more than 7 million people in the United States, according to the Centers for Disease Control and Prevention (CDC), and it is the leading cause of vision impairment and blindness in working-age adults. Because it does not cause symptoms in its early stages, though, many people do not realize that they have the condition.
About Diabetic Retinopathy
Diabetic retinopathy is the result of damage to blood vessels in the eye. Light carries visual information about the world into the eye, and strikes a light-sensitive layer of tissue lining the back of the eye. This tissue, known as the retina, absorbs the light and converts the visual information into electrical impulses. The optic nerve transmits these impulses to the brain, which translates the impulses into the images a person sees.
A network of blood vessels delivers the constant supply of oxygen and nutrients the retinal tissue needs to function. High blood sugar levels, like that experienced by people with diabetes, can damage the blood vessels in the retina. In time, exposure to high blood sugar can cause the blood vessels to swell and leak blood or other fluids, resulting in cloudy or blurred vision.
Long periods of high blood sugar can cause fluid to accumulate in the lens of the eye, which controls how the eye focuses the light entering the eye. Fluid accumulation can change the curvature of the lens, which can affect how well the eye focuses. The lens will return to its original shape and vision should improve once blood sugar levels normalize. Improving control over blood sugar levels can slow the onset and progression of diabetic retinopathy.
Blood vessels can also close to stop the flow of blow to the retina completely. In some cases, abnormal new blood vessels can grow on the retina. Each of these changes can cause long-term vision loss or blindness. The growth of new blood vessels associated with diabetic retinopathy can also cause complications that can lead to serious vision problems. These complications include:
Vitreous hemorrhage – occurs when blood vessels leak blood into the clear, jelly-like substance filling the eye
Retinal detachment – abnormal blood vessels can stimulate the growth of scar tissue that can pull the retina away from the back of the eye
Glaucoma – new blood vessels growing at the front of the eye prevent the normal flow of fluid out of the eye, causing pressure to build up inside the eye; this pressure can damage the optic nerve
Blindness – diabetic retinopathy or glaucoma associated with diabetic retinopathy can lead to complete vision loss
There are two main forms of diabetic retinopathy. Proliferative diabetic retinopathy (PDR) involves the formation of abnormal blood vessels in the retina; it is the more severe form of the disease. Non-proliferative diabetic retinopathy (NPDR) is milder and does not typically cause symptoms.
Risk factors for diabetic retinopathy
Anyone who has type 1 or type 2 diabetes can develop diabetic retinopathy, but certain factors can increase the risk of developing this eye condition. Risk factors for diabetic retinopathy include:
- Duration of diabetes — the longer someone has diabetes, the greater their risk of developing diabetic retinopathy
- Poor blood sugar control
- High blood pressure
- High cholesterol
- Tobacco use
- Being African-American, Hispanic or Native American
Symptoms of diabetic retinopathy
Diabetic retinopathy typically affects both eyes. Symptoms of diabetic retinopathy typically include:
- Seeing floaters or spots
- Blurred vision
- Having an empty or dark spot at the center of vision
- Trouble seeing at night
Diagnosis and treatment of diabetic retinopathy
While diabetic retinopathy does not usually cause symptoms in its early stages, eye doctors can detect the signs of this eye condition using a variety of methods. A dilated eye exam involves the administration of eye drops that widen the pupil, which allows the eye doctor to view inside the eye. An eye doctor may photograph the interior of the eye to look for abnormalities in blood vessels, optic nerve or retina, as well as signs of new blood vessels, changes in eye pressure, retinal detachment or scar tissue.
An eye doctor may perform other tests, such as fluorescein angiography to take pictures of blocked, leaking or broken down blood vessels, or optical coherence tomography (OCT) that produces high-resolution cross-sectional images of the retina.
Left untreated, diabetic retinopathy can cause blindness. Treatment depends largely on the severity and type of diabetic retinopathy. Treatment may include the use of lasers to seal blood vessel leaks or vitrectomy to remove excess fluid from within the eye.
For more information about diabetic retinopathy, contact Coldwater Vision Center.