January 23, 2014

Eye Disease – Diabetic Retinopathy

I have written about two of the three eye diseases that people with diabetes are at risk to develop – cataracts and glaucoma. Now it is diabetes retinopathy. Many authors just use the term diabetic eye disease for retinopathy, cataracts, and glaucoma. Diabetic retinopathy is the most common eye disease in people with diabetes. It affects over 5 million Americans aged 18 and older. Usually both eyes develop the disease. Diabetic retinopathy progresses in four stages.

The four stages of diabetic retinopathy are:
  1. Mild Nonproliferative Retinopathy. At this earliest stage, microaneurysms occur. They are small areas of balloon-like swelling in the retina's tiny blood vessels.
  2. Moderate Nonproliferative Retinopathy. As the disease progresses, some blood vessels that nourish the retina are blocked.
  3. Severe Nonproliferative Retinopathy. Many more blood vessels are blocked, depriving several areas of the retina with their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment.
  4. Proliferative Retinopathy. At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They grow along the retina and along the surface of the clear, vitreous gel, that fills the inside of the eye. By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can result.

This tells you how important glycemic management is to preventing retinopathy. Damaged blood vessels can cause vision loss and blindness in two ways. First, fluid leaks into the center of the retina, named the macula. The fluid causes the macula to swell, blurring vision. Second, in proliferative retinopathy, new and abnormal blood vessels grow and can cause vision to blur by leaking blood into the center of the eye. This can cause scar tissue and lead to retinal detachment.

Everyone with diabetes, regardless of type, is at risk for retinopathy. The longer you have had diabetes, the more your risk becomes. The National Eye Institute says up to 45 percent of Americans diagnosed with diabetes have some form of diabetic retinopathy.

Identifying yourself as being at risk for proliferative retinopathy is macular swelling that can develop without and with symptoms. Vision can remain unaffected as the eye disease progresses. Your risk of vision loss is high. This is one reason you should have annual eye exams and why they are necessary. If you thought getting a diabetes diagnosis because you had no symptoms, diabetic retinopathy may go unnoticed before taking action. This again is the reason for having an annual eye exam and more often if needed. Vision is not something to delay until it is noticeably affected and then treatment may be less effective.

See your eye doctor right away if you notice any of these symptoms:
  • Blurred vision – this is very common in people with diabetes who have unmanaged blood sugar levels even without the presence of retinopathy.
  • "Floaters" that swim in and out of your vision in one eye that last longer than a few days. These may be ordinary harmless floaters, but don't take chances. If you have diabetes especially, floaters may be the sign of bleeding in the back of the eye. New floaters are always a reason for seeing an eye doctor, especially when you have diabetes.

Two treatments are used for diabetes retinopathy:
  1. "Scatter" laser treatment (pan-retinal photocoagulation) is effective for treating new blood vessels before or after they begin to bleed. Severe bleeding may be treated with a surgical procedure (vitrectomy) by removing blood from the center of the eye.
  2. "Focal" laser treatment may be done to stabilize vision. This therapy may reduce vision loss by up to 50 percent.

These laser treatments may reduce the risk of serious vision loss and blindness, but they cannot cure diabetic eye disease. They cannot bring back lost vision or prevent future vision loss.

Read my blog here about the Johns Hopkins study, where less than half of the adults who are losing their vision to diabetes claim they have not been informed by a doctor that diabetes could damage their eyesight. This is more than the third that don't obtain proper vision care. It is obvious that many people with diabetes do not see their eye doctors when they have diabetes. This is another reason for anyone with diabetes to have an annual dilated eye exam. Once there are noticed changes in their eyes, then people may need their eyes examined more frequently.

Managing your blood glucose levels carefully and your blood pressure within the normal range will help as well. Always follow your doctor's recommendations regarding medication, diet, and exercise.

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