According to the CDC, in 2018, about 34.2 million Americans — 10.5% of the population — had been diagnosed with diabetes. The disease increases blood sugar levels, either because the body doesn’t have enough of the hormone insulin to move the sugar into the cells, where it’s used for energy (Type 1), or because the cells become resistant to the hormone’s effects (Type 2).
In adults, about 90-95% of cases are Type 2, the most preventable form. Risk factors for the disease include a poor diet and a sedentary lifestyle.
At Retina Specialists, our team of expert ophthalmologists regularly performs diabetic eye exams at our five locations around the Dallas, Texas, area, to evaluate, diagnose, and treat diabetes complications affecting the eyes.
If you have diabetes or are at risk for developing it, here’s why these exams are so important, and what questions you should ask to be the best informed you can be about your condition.
Looking through the eye
To understand how diabetes affects the eyes, it helps to know the eyeball’s anatomy. To do that, let’s follow how light travels.
Ambient light first hits the eye’s surface, which is covered with a clear, curved, and tough membrane. Because it’s clear, the light can pass through. Because the membrane (cornea) is curved, it focuses that light while protecting the eye.
The light next moves through a fluid-filled area called the anterior chamber (containing a watery aqueous humor), through the hole of the pupil, and then through a clear lens that focuses it more finely. Finally, it passes through another chamber (the vitreous humor), striking the retina at the back.
The retina converts the now-focused light into electrical signals, transmitting them to the brain through the optic nerve. Your brain decodes the signals so you can “see” the image.
The central 2% of the retina, called the macula, registers your clear, central vision. It’s nourished by blood vessels in and behind the retina.
Visual complications of diabetes
The high sugar levels characteristic of diabetes can lead to several complications that can rob you of sight if not treated. Diabetic retinopathy is a major cause of blindness, affecting more than one in four American adults living with diabetes.
In its early stages, supporting blood vessels leak into the retinal tissue, causing the macula to swell (macular edema), which leads to blurred vision. As the disease progresses, vessels close off, starving the macula of oxygen and other essential nutrients. To compensate, new vessels proliferate on the retina’s surface, which can lead to scar tissue, a detached retina, and/or loss of sight.
Glaucoma is a collection of eye conditions that damage the optic nerve. High blood sugar levels interfere with the eye’s drainage system, increasing the fluid pressure inside your eye and leading to nerve damage. Glaucoma is a sneaky disease — it often doesn’t produce any symptoms until the damage is done.
Questions to ask at your next diabetic eye exam
When you come into Retina Specialists for a diabetic eye exam, your ophthalmologist evaluates both your vision and your eye health, paying special attention to the eye structures that diabetes typically damages.
These annual exams are a good time to get more information from your doctor about how your diabetes affects your eyes and what you can do to prevent complications. Some good questions to ask are:
What is my intraocular pressure?
It may be an air puff test, a tonometer that rests against the cornea, or an automated device, but the ophthalmologist always checks your eye pressure. That’s because building pressure from improper drainage can signal the beginning of glaucoma.
Eye pressure varies, and normal levels are considered 12-21 mgHg. Anything over 21 is considered high, and the doctor will want to treat it to prevent damage to the eye. Knowing your numbers helps keep your eyes safe.
Do my retina and optic nerve look normal?
The doctor dilates your eyes for your exam so he can see all the internal structures. Since the retina and optic nerve can both be damaged by diabetes, you want to make sure they’re still healthy so you can keep them that way.
What lifestyle changes can I make to help protect my eyes?
As we’ve said, Type 2 diabetes is highly preventable, and most of that prevention comes from lifestyle choices. Your doctor will have a unique view on how your disease can affect your eyes, so getting his opinion on how to prevent problems is a good idea.
Are you diabetic but haven’t had an eye exam recently? Then it’s time to come into Retina Specialists for a comprehensive diabetic eye exam. Call us at any of our five Texas offices — in Dallas, DeSoto, Plano, Mesquite, and Waxahachie.