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Diabetic Retinopathy

How Diabetes Can Affect Your Vision

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Updated November 29, 2011

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Diabetic Retinopathy

The retina is located at the back of the eye and acts much like a camera, capturing the image as it comes through the eye.

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Diabetes can affect many parts of your body, including your eyes. Those with either type 1 or type 2 diabetes are at greater risk of vision problems than someone without diabetes. But this doesn’t mean that serious vision problems are inevitable. Early detection can treat most diabetes-related vision problems before they steal your sight.

Diabetic Retinopathy

What is the retina?

The retina is located at the back of the inner eye. It is sensitive to light and acts like the film in a camera: As images come into the eye, they are focused on the retina. The retina then takes these images, converts them to electrical signals and sends them to the brain through the optic nerve.

What is diabetic retinopathy?

Diabetic retinopathy is a general term that describes disorders of the retina that are caused by diabetes. There are two types of retinopathy common with diabetes.

  • Nonproliferative retinopathy
  • Proliferative retinopathy

Nonproliferative Retinopathy

The most common type is called nonproliferative retinopathy. In nonproliferative retinopathy, the small capillaries (blood vessels) in the retina swell and begin to restrict the movement of blood and fluid. Nonproliferative retinopathy often has no noticeable symptoms. Even when it is detected early with an eye exam, treatment is usually not necessary. But annual eye exams are vital to monitor the possible progression of the disorder once it has been identified.

Proliferative Retinopathy

In some people, nonproliferative retinopathy progresses and creates more significant complications with vision. This advanced stage is called proliferative retinopathy and is characterized by capillaries in the retina that completely shut off the blood and fluid flow. This shutdown of the existing blood vessels causes new blood vessels to start growing in the retina. While this sounds like a promising alternative to the blocked capillaries, these new vessels are typically weak and often leak blood and fluid, which can blur or block your vision. When this happens, it can cause two significant problems: macular edema and retinal detachment.

Macular edema

Macular edema occurs when the fluid from the weak capillaries leaks into the macula, which is responsible for focusing your eye. Leaking of fluid into the macula causes your vision to be blurred and can result in permanent damage to your vision.

Retinal detachment

Retinal detachment occurs when newly formed blood vessels in the retina form scar tissue. As the scar tissue shrinks, it pulls the retina out of place and away from the back of your eyeball.

Both macular edema and retinal detachment can eventually result in blindness if not treated.

Symptoms of Retinopathy

It is usually when retinopathy has progressed to the proliferative stage that symptoms might become evident. They include:

  • Blurred vision or slow vision loss over time
  • Shadows or missing areas of vision
  • Trouble seeing at night
  • Floaters

Risk Factors for Retinopathy

These factors increase your risk for retinopathy.

Most people with diabetes will eventually get some form of retinopathy; this risk increases with the amount of time you’ve had diabetes. But the more serious proliferative retinopathy is less common.

Treatment for Retinopathy

The good news is that there are effective treatments for retinopathy. The earlier retinopathy is detected, the better the potential outcome.

The most common procedure is one of two types of laser treatments that create small burns in the retina where there are abnormal blood vessels. The process is called photocoagulation and it is used to stop leaking blood vessels in the retina. Photocoagulation can be scattered over the whole surface of the retina or focused specifically on the macula, depending on the problem that needs to be addressed.

If the retina is detached, photocoagulation is no longer effective and a procedure called vitrectomy is used to remove scar tissue and fluid from inside the eye.

Treatment can reduce vision loss but it cannot reverse damage that has already occurred. That is why prevention is your best defense against retinopathy.

Preventing Retinopathy

The best way to protect your vision is to have an annual eye exam with an eye doctor trained to treat diabetic retinopathy. This exam dilates your pupils with eye drops and looks carefully at your retina for any signs of disease.

Your next best means of prevention is to maintain good control over your blood glucose levels, your blood pressure and cholesterol. If you smoke, stop. Contact your eye doctor if you notice any vision problems between annual exams.

Source:

American Diabetes Association. "Eye Complications."

National Library of Medicine. "Diabetic Retinopathy.”

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