Q:   My doctor says that diabetes can cause eye disease. How does this happen?
A:  

It is true. Diabetes can cause eye disease. In fact, it is the most common cause of blindness in the United States.

Research to date has demonstrated that increased blood sugar can damage the retina, the important part of the back of your eye that helps you to see. Over time, this slow damage can become significant enough to affect your vision. The medical term for this eye disease due to diabetes is "diabetic retinopathy."

It is important to note that your blood sugar levels can correspond to the severity of the eye disease. That is, the poorer your blood sugar control, the worse your eye disease can become.

To help you understand the progression of the degeneration, some detail around the stages is provided. In the early stages, tiny blood vessels become weak. Small amounts of blood leak out from the weakened walls. The fluid that follows the blood and the healing process causes a hardening, which your doctor can see on exam (called "yellow exudates"). This is a sign of the beginning of eye disease. As the condition becomes more severe, the tiny blood vessels (called capillaries) will be blocked off, reducing the supply of blood to your retina. This causes more severe damage and scarring to the retina. Eventually, in the later stages, in an attempt to get blood to the retina, new, weak blood vessels form (or proliferate) in the dead areas. More bleeding can occur to worsen the damage.

One of the most dangerous outcomes due to this damage is the detachment of the retina due to the multiple damaged areas. This can cause blindness.

While diabetic retinopathy is a potentially severe form of eye disease due to diabetes, it is not the only type. Note that other conditions such as glaucoma and cataracts are also quite common. If you have diabetes, it is recommended that you have your eyes checked by an ophthalmologist regularly. Talk to your doctor about the care of your eyes.

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