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Eye and Vision Care

Diabetes and Your Eyes

If you have diabetes, your body has trouble controlling sugars. Large amounts of sugar in your blood put a strain on your blood vessels. Diabetes affects all the blood vessels in your body, but the delicate blood vessels inside your eyes and kidneys are most vulnerable. Although you may not notice any symptoms for many years, this can cause permanent damage to your eyes; even resulting in blindness.

The retina is light-sensitive tissue that lines the inside of the eye. It functions like the film inside a camera. Diabetic Retinopathy is damage to this tissue caused by diabetes.

How does it happen?

Our blood vessels are not designed to hold a lot of sugars. Having high blood sugar puts a lot of stress on your blood vessels.

If your sugars are high for a long period of time, your blood vessels will become thick, weak, and eventually break down. This happens to the blood vessels in your eyes, kidneys, and all over your body.

Over time, your vessels will become weak and leaky. This may cause bleeding or swelling.

With worsening damage, the blood vessels will be unable to carry and deliver blood as it used to. Parts of the eye will not get the blood supply they need, and they will become starved for oxygen.


Early Changes - Non-proliferative Diabetic Retinopathy

This is a simple drawing of your eye.

The retina is shown in gray - it lines the back of your eye and functions like the film in a camera.

The blood vessels, shown in red, lie along the retina and supplies it with the oxygen and nutrients it needs to survive.

The early stage of diabetic eye disease is called Non-proliferative Diabetic Retinopathy.

Your eye doctor may see small outpouchings, called aneurysms, or a small amount of bleeding from the vessels in the back of your eye.


The weak, leaky vessels can cause swelling in parts of the eye, which may lead to blurry vision. This may be reversible, but it could cause permanent decrease in your vision.

With further damage, he may also see pale areas in the back of the eye that are not receiving enough oxygen and nutrients.

Late Change - Proliferative Diabetic Retinopathy

The late stage of diabetic eye disease is called Proliferative Diabetic Retinopathy. This occurs if the vessels are so damaged that they are not able to supply the eye with the oxygen and nutrients it needs to survive. Parts of the retina become starved of nutrients, and they begin to produce a chemical that stimulates new blood vessels to grow.


Imagine the normal vessels as a field of grass covering the inside of the eye. These new blood vessels are like weeds – instead of growing along the curvature of the eye like normal vessels, they grow towards the middle of the eye



These new, abnormal blood vessels are prone to break, bleed, and tear the retina – leading to vision loss.


Scarring from bleeding and leaky vessels can cause retinal detachment, where the retina lifts off the back of the eye. This will cause you to see flashing lights, and may result in permanent vision loss.


What can I do?

1. Control your blood sugar – it is the best way to prevent eye disease and damage to your other organs

2. Have a dilated eye exam every year – you may not notice any changes in your vision until it is too late. Diabetic eye disease develops over many years – finding and treating it early can prevent vision loss 95% of the time. Warning signs:

Who gets Diabetic Eye Disease?

The longer you have had diabetes, the more likely you are to have eye problems

Protect your eyes by:

Tests your doctor might order:

Dilate Fundus Exam

Fluorescein Angiography

Optical Coherence Tomography (OCT)

Treatment Options

There are very good treatments to slow diabetic eye disease and stop the damage if the disease is caught early

Hope Through Research - You Can Be Part of the Answer!

Many research studies are underway to help us learn about eye diseases. Would you like to find out more about being part of this exciting research? Please visit the following links:


Prepared in partnership with Lily Huang, MD, Class of 2013, Case Western Reserve University School of Medicine.

For more information:

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Last Reviewed: Nov 07, 2012

Suber S Huang, MD, MBA Suber S Huang, MD, MBA
School of Medicine
Case Western Reserve University