Why are regular eye exams so important for people with diabetes?

Diabetes affects tiny blood vessels all throughout our body—in our hearts, brains, kidneys, toes and eyes. Diabetes can affect the eyes in many ways, from the front of the eyes to the back of the eyes.

A common issue we see in people who have diabetes is vision that goes from clear to blurry and back again. Sometimes people will tell me, “Some days I feel like I see better out of my old glasses, and they are a completely different prescription!”

The good news is, you are not crazy! When the blood sugars change in your body, the lens inside your eye can swell and then shrink. And if the lens inside your eye is changing size and focusing power, the size and focusing power of your glasses would need to change to keep you seeing clearly. This is one of the reasons why it is not recommended to get your eyeglass prescription measured when your blood sugars are still going from very high to very low.

However, even with steady blood sugars, you can still have vision that goes from clear to blurry and back again if your eyes are dry. People with diabetes are more likely to have dry eyes.

When we do things like drive for long distances, read for long periods of time, watch a good movie or surf the net on our computers, we do not blink as often. Our brain stops our natural reflex to blink because it says, “Hold on eyelids! I’m looking at something! Don’t blink yet!” When you combine less blinking with eyes that are dry and do not have healthy tears, the vision can be just as blurred as looking through a dry and dirty windshield. Using a lubricating teardrop from time to time is helpful, but some people need more advanced treatments for their dry eye.

Although cataracts are a universal eye-related result of aging, people with diabetes can get cataracts at a younger age. Because the lens swells and shrinks with variations in blood sugar, it ages faster and creates a cataract sooner.


One of the most dangerous eye disease related to diabetes is called retinopathy. The retina is a very delicate nerve tissue that lines the back of the eye like wallpaper. There are lots of tiny blood vessels in the retina that help bring oxygen and nutrients so that the retina can work and send signals to our brain of what we are seeing.

Retinopathy is when the tiny blood vessels in the back of the eye start to leak, bleed or close off from having blood sugar that is too high for too long. The early signs of diabetic retinopathy are call microaneurysms. A microaneurysm is a tiny bulge in a small blood vessel. This is a little different that the aneuyrsms that people can have in their brain or in their stomachs.

Other things your eye doctor can see are small blood spots in the retina from where the damaged blood vessels have leaked out a little fluid. When the fluid keeps leaking, the layers of the retina can become swollen and separate, and if that occurs in the very center of the retina, it can start to affect your vision.

One of the most difficult parts of catching diabetic retinopathy early is that a lot of this damage can start WITHOUT affecting your vision, but if you wait until your vision changes, it may be too late to fix things. Sometimes I tell people it can be like trying to stop a speeding train. We can grab on, dig in our heels, grind those brakes, but that train will keep moving for a while before we get it stopped. That is why it’s important to have your eyes check once a year if you have diabetes, EVEN IF YOU HAVE GREAT VISION!

When we can see this damage starting in the eyes, it could be a sign that there is similar damage happening in other parts of the body, like the heart, brain or kidneys. If we recognize the early signs, we can look at this like a canary in the coal mine. We inform the primary care providers and discuss ways to try to get the blood sugars and blood pressure under better control.

If retinopathy progresses, we may start to see new blood vessels in the back of the eye trying to grow to make up for the ones that have been damaged. This can work well in other parts of the body, but it does not work well in the retina. The new blood vessels are weak and grow in the wrong spots. They can pop and bleed, and then create scars that pull and tug on the retina.

The best thing to do for diabetic retinopathy is to do what you can to help your small vessels get healthy. If you are a smoker, quitting is so important. If you are struggling with diet and exercise, talking with your primary care provider to get a good plan of action is key.

If you are having side effects from your medicines that discourage you from taking them, if you are not able to afford them, or if they are too difficult to remember, have realistic discussions with your care team to try to set up a more manageable plan moving forward.

The best plan is to get the blood sugars and blood pressure under control. That is the only treatment for early retinopathy. Sometimes, we will move yearly appointments closer together to make sure things are not getting worse. If diabetic retinopathy starts to threaten vision, treatments like lasers, injections of medicine into the eye, or surgery may be needed.

If you want to know how your diabetes is affecting your eyes, call 864-522-3900 and make an appointment today.

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