How Does Diabetes Affect the Eyes?

Author: Premier Eye Associates

Diabetes is one of the most rapidly expanding diseases in the United States. In fact, as of 2022 over 11% of the United States’ population has been diagnosed with some form of diabetes.

Many individuals understand that diabetes is a disease that results in poor blood sugar control within the body, resulting in sugar highs and lows that can cause detrimental affects to the human body.

What many individuals do not know is that the eyes are particularly susceptible to diabetic changes, making at least yearly eye exams critical for diabetics to monitor for subtle changes and treatment intervention when necessary.

This article is aimed to answer some of the more commonly asked questions between the relationship between diabetes and the eyes, to create a better understanding of the importance of diabetic eye exams.


How Does Diabetes Affect the Eyes?

Diabetes affects the eyes in several different ways. The first belonging to the backmost structure of the eye, the retina. The retina is a thin structure lining the back of the eye containing light-detecting cells called photoreceptors. Photoreceptors obtain information from incoming light rays and then transmit this information to the brain for processing. Therefore, damage to the retina can result in irreversible vision loss.

The retina has its own special blood supply. The blood supply of the retina is very unique to ensure blood does not leak out or course through areas that would interfere with the receiving of light rays nor the transmission of signals to the brain.

Diabetes can damage these unique blood vessels in a condition called diabetic retinopathy. Excess blood sugar causes structural damage to the blood vessels, causing them to leak blood, exudates, and inflammation into the retina rather than reaching the intended areas to provide needed nutrients. If this continues over time, the retina will begin to grow new blood vessels to compensate for non-perfused areas in a process called neovascularization.

The new blood vessels grown are not of the same caliber as the original blood vessels. They are thin, leaky, and often grow in areas they should not. These new blood vessels can obscure the transmission of light as well as create areas of traction within the retina, increasing the risk for retinal detachment.

Not only is the retina affected, but diabetes can also affect the lens of the eye. The lens is a clear structure located near the middle of the eye. It is flexible to allow an individual to see at various distances (far, intermediate, near, etc.).

Increased blood sugar can cause the lens to swell, shifting an individual’s prescription and making vision blurry. The amount of swelling in the lens depends on blood sugar levels, and therefore will change day-to-day, making glasses essentially useless. Getting blood sugar levels under control will alleviate this process.

Diabetes also increases the rate of cataract formation, increases risk for developing glaucoma, and can cause swelling of the eye (macular edema).


What are Eye Symptoms of Diabetic Changes?

There really aren’t too many symptoms a person will notice with diabetic changes in the eye due to lack of pain-sensing nerves in the back of the eye.

An individual may experience blurry vision, or a sudden change in clarity of vision, when blood sugars are elevated.

Additionally, if severe bleeding and/or retinal detachment is occurring in the eye, a person may notice flashes of light, hundreds of black or red floaters within the eye, or the appearance of a curtain or shadow in his or her vision.

What type of diabetes is more detrimental to the eye?

The type of diabetes does not matter so much as the length of time in which an individual has had diabetes. The longer an individual has had diabetes, even if blood sugar control is good, the more likely it is to see diabetic changes within the eye. All types of diabetes pose risk for development of diabetic retinopathy—type 1, type 2, gestational, and even diabetes insipidus.

I’m diabetic, what can I do to prevent diabetic changes in the eye?

Good blood sugar control is the best way to prevent diabetic changes in the eye. We recommend an A1c level of 7.0% or lower. This is best accomplished via a healthy diet full and regular exercise.

Regular dilated eye exams—at least once yearly—to get a good look at the health of the retina is also of upmost importance. The retina does not contain pain-detecting nerves, so an individual will not have symptoms associated with diabetic retinopathy besides vision loss—which can be permanent. For this reason, doctors will want to monitor for subtle changes and intervene with treatments when necessary prior to an event resulting in permanent vision loss.


Are there Treatments for Diabetic Eye Changes?

First and foremost, you will want to get your blood sugar levels under control. Highly fluctuating blood sugar levels puts added stress on the blood vessels, which is what we want to avoid.

Small amounts of bleeding or inflammation within the eye secondary to diabetes can often just be monitored while working to stabilize blood sugar levels. Once the blood sugar levels have been stabilized, the eye is usually able to reabsorb the blood and things are fine.

In other cases of more severe bleeding or neovascularization, a laser treatment may be recommended to prevent further damage from expanding. This laser treatment may reduce the extent of an individual’s peripheral vision, but can potentially save an individual’s central vision.

If you or someone you know has been diagnosed with diabetes and needs an eye exam, be sure to give us a call today! We would be happy to evaluate the health of your eyes and discuss your personal situation with you to help prevent diabetic retinopathy and keep your eyes healthy and seeing well for many years to come.


Dr. Anthony Spina and the staff of Premier Eye Associates specialize in glasses, soft contact lenses, hard contact lenses, and medical eye exams. Call our eye doctor in Auburn, AL today at (334) 539-5391 or schedule an appointment online  if you are interested in learning more about diabetes affect on your eyes.  Our optometrist provides only the highest quality eye care services amongst eye doctors in the Auburn Alabama area.

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