Diabetes and Eyesight

Diabetes is a disease that affects the way we process food for energy and growth. With all forms of diabetes—type 1, type 2 and gestational diabetes—the body has trouble converting sugar in the blood into energy, resulting in a host of potential health problems.
Diabetes increases the likelihood that common diabetes-related vision problems or diseases might occur:

  • Diabetics are prone to developing cataracts (a clouding of the eye’s lens) at an earlier age.

  • People with diabetes are almost 50% more likely to develop glaucoma, an eye disorder that damages the optic nerve often marked by an increase of internal eye pressure.

  • Macular edema (and macular degeneration) are more common in diabetics due to malfunctioning blood vessels in the middle region of the retina responsible for central, sharp vision.

  • Most notably, diabetes can result in diabetic retinopathy; an eye disease that affects the blood vessels in the all-important retina. Nearly 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy.

That’s why there’s no separating diabetes and vision. If you have diabetes, then you should understand vision problems that increase in likelihood as a result of the disease.

Diabetes Statistics

Over 21 million people in the United States have diabetes, with an estimated additional 6 million people unaware they have a form of the disease. What’s more, an estimated 54 million Americans ages 40 to 74 have prediabetes, a condition that puts them at risk for developing type 2 diabetes. According to a recent American Optometric Association survey, diabetes is the leading cause of new cases of blindness among adults ages 20 to 74.

Overview Of Diabetic Retinopathy

Diabetic retinopathy involves swelling, leaking or abnormal growth of blood vessels in or near the retina. There are multiple stages to this disease, the earliest of which may not present any symptoms you can see.

Symptoms you can see include dark or black spots in your vision that increase over time, or severely blurred vision due to bleeding within the eye.
That’s why comprehensive eye exams are so important when thinking about diabetes and eye sight—both type 1 and type 2 diabetics are at risk for developing diabetic retinopathy, and the longer you have diabetes, the more likely you are to develop some form of the disease.

Treatments for diabetic retinopathy include replacement of the inner gel inside the eye (called a vitrectomy) and different kinds of laser surgery. A recent clinical trial also suggested that better control of blood sugar levels slows the onset and progression of the disease in many patients.

Signs And Symptoms Of Diabetic Retinopathy

In its advanced stages, diabetes may lead to new blood vessel growth over the retina. The new blood vessels can break and cause scar tissue to develop, which can pull the retina away from the back of the eye. This is known as retinal detachment, and it can lead to blindness if untreated. In addition, abnormal blood vessels can grow on the iris, which can lead to glaucoma. People with diabetes are 25 times more likely to lose vision than those who are not diabetic, according to the American Academy of Ophthalmology.

Anyone who has diabetes is at risk for developing diabetic retinopathy, but not all diabetics will be affected. In the early stages of diabetes, you may not notice any change in your vision. But by the time you notice vision changes from diabetes, your eyes may already be irreparably damaged by the disease.

That’s why routine eye exams are so important. Your eye doctor can detect signs of diabetes in your eyes even before you notice any visual symptoms, and early detection and treatment can prevent vision loss.

Floaters are one symptom of diabetic retinopathy. Sometimes, difficulty reading or doing close work can indicate that fluid is collecting in the macula, the most light-sensitive part of the retina. This fluid build-up is called macular edema. Another symptom is double vision, which occurs when the nerves controlling the eye muscles are affected.

If you experience any of these symptoms, see your eye doctor immediately. If you are diabetic, you should see your eye doctor at least once a year for a dilated eye exam, even if you have no visual symptoms.

If your eye doctor suspects diabetic retinopathy, a special test called fluorescein angiography may be performed. In this test, dye is injected into the body and then gradually appears within the retina due to blood flow. Your eyecare practitioner will photograph the retina as the dye passes through the blood vessels in the retina. Evaluating these pictures tells your doctor or a retina specialist if signs of diabetic retinopathy exist, and how far the disease has progressed.

Causes Of Diabetic Retinopathy

Generally, diabetics don’t develop diabetic retinopathy until they have had the disease for at least 10 years. As soon as you’ve been diagnosed with diabetes, you need to have a dilated eye exam at least once a year.

In the retina, high blood sugar can damage blood vessels that can leak fluid or bleed. This causes the retina to swell and form deposits. This is an early form of diabetic retinopathy called non-proliferative or background retinopathy.

In a later stage, called proliferative retinopathy, new blood vessels grow on the surface of the retina. These new blood vessels can lead to serious vision problems because they can break and bleed into the vitreous, the clear, jelly-like substance that fills the interior of the eye. Proliferative retinopathy is a much more serious form of the disease and can lead to blindness.

Fortunately, you can significantly reduce your risk of developing diabetic retinopathy by using common sense and taking good care of yourself:

  • Keep your blood sugar under good control.

  • Maintain a healthy diet.

  • Exercise regularly.

  • Follow your doctor’s instructions to the letter.

Treatment For Diabetic Retinopathy

Diabetic retinopathy can be treated with a laser to seal off leaking blood vessels and inhibit the growth of new vessels. Called laser photocoagulation, this treatment is painless and takes only a few minutes.

In some patients, blood leaks into the vitreous humor and clouds vision. The eye doctor may choose to simply wait to see if the clouding will dissipate on its own, or a procedure called a vitrectomy may be performed to remove blood that has leaked into the vitreous humor.

​​​​​​​Small studies using investigational treatments for diabetic retinopathy have demonstrated significant vision improvement for individuals who are in early stages of the disease. Two medications that are closely related, Lucentis and Avastin, may be able to stop or reverse vision loss, similar to very promising results that have been reported when the two drugs have been used as treatments for macular degeneration.