Why Diabetics Need Annual Dilated Eye Exams

Medically Reviewed By William C. Lloyd III, MD, FACS
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Having diabetes increases your risk of certain eye complications that can cause vision loss. This isn’t something to be scared of, but it is something to be aware of. An annual dilated eye exam can catch signs of disease early to preserve your vision. In fact, a full 90% of diabetes-related blindness can be prevented through early detection and treatment.

What to Expect from an Annual Dilated Eye Exam

If you’ve had an eye exam in the past, some parts of the annual dilated exam will be familiar to you. Other parts may be new, but don’t worry. They aren’t painful or usually even uncomfortable. A typical annual dilated eye exam includes:

  • An eye chart test to determine your ability to see at different distances

  • An “air poof” test to check the pressure inside your eyes

  • Pupil dilation through drops in your eyes that help your ophthalmologist examine your retina and optic nerve, which connects the eye to the brain

  • Optical coherence tomography (OCT) to capture images of your retina

After an annual dilated exam, your eyes will be sensitive to light. Your doctor will likely give you disposable sunglasses, or you can wear your own. The test may seem like an inconvenience, but it can help you prevent the development of diabetes-related eye diseases like diabetic retinopathy, diabetic macular edema, age-related macular degeneration, cataracts, and glaucoma.

Diabetic Retinopathy

Diabetic retinopathy is the most common cause of decreased vision for those with diabetes. It causes the delicate blood vessels of the retina, which we rely on for sensing light, to swell and leak fluid. As the disease progresses, the original blood vessels constrict and blood flow is interrupted. In response, abnormal new blood vessels proliferate. These new vessels leak profusely. This can cause permanent vision loss, including total blindness. It’s estimated that about 40% of those with diabetes in the United States have diabetic retinopathy, but only half know it.    

However, it’s important to know if you have diabetic retinopathy, because it’s highly treatable, especially if discovered early. The annual dilated eye exam is key to early detection, because there are typically no symptoms until vision is lost. Treatment can be as simple as better control of blood sugar and blood pressure. Injectable medications called anti-VEGF therapies can stop blood vessels from growing excessively and decrease levels of fluid in the retina. Oral medications can reduce swelling, and laser procedures can seal blood vessel leaks. If leakage is severe, traditional surgery may be an option.   

Diabetic Macular Edema

About half of those with diabetic retinopathy go on to develop diabetic macular edema (DME). This happens when the swelling, or edema, within the retina extends to the macula, the critical part of the retina responsible for our central vision. Without it, we wouldn’t be able to identify faces, drive, read, write, or cook. DME is more likely to occur if diabetic retinopathy is left untreated and gets worse.

Blurred vision can be a symptom of DME, but it doesn’t always happen. An annual dilated eye exam gives your ophthalmologist the chance to monitor for signs that diabetic retinopathy is progressing into DME and recommend treatment to slow it. There are three main treatments for DME that can be given individually or at the same time.  Similar to proliferative diabetic retinopathy, anti-VEGF therapies, given by injection, help stop the overgrowth of abnormal new blood vessels and decrease excess fluid in the retina. Laser procedures can also be used to reverse DME. Corticosteroids, either given by injection or implanted in the eye, can also suppress macular swelling.

If your doctor sees signs of DME on an eye exam, a fluorescein angiogram may also be recommended. You’ll be given an injection of fluorescent dye to enable the capture of detailed images of blood vessels in the retina. 

Age-Related Macular Degeneration

Additional eye diseases can affect those who have diabetes as well as those who don’t, but the risk is greater for people with diabetes. Several studies have shown a connection between having diabetes and a higher risk of age-related macular degeneration (AMD), the leading cause of vision loss in people age 50 and over. The most common symptom of AMD is blurry vision in the center of one or both eyes that may get bigger over time or start to include “blank spots.” AMD occurs when the macula is damaged, impacting your central vision.

Like other eye diseases, AMD may begin without symptoms, so an annual dilated eye exam is the only way to identify it. Your doctor may confirm an AMD diagnosis by asking you to look at an Amsler grid. Its straight lines may appear wavy or seem to disappear if you have AMD. Some studies have shown that a combination of certain vitamins and minerals in high doses can significantly slow the progression of certain forms of AMD. Before trying nutritional supplements, ask your doctor for advice. Treatments for age-related macular degeneration include anti-VEGF injections, and laser therapy.

Cataracts and Glaucoma

Like AMD, cataracts and glaucoma can affect anyone, but the risk is higher for those with diabetes. The chance of developing cataracts, which cloud the lens of the eye and impair vision, is two to five times higher if you have diabetes. The chance of developing glaucoma, which raises pressure in the eye and damages the optic nerve, is twice as high.

The sooner you know you have cataracts, the sooner you can take simple steps to see better. Cataract surgery is effective for about 90% of people, but it may not be necessary at first. Prescription eyeglasses, anti-glare sunglasses, or magnifying lenses can all enhance your vision. Brighter lighting in your environment can help, too. Surgery to remove cataracts may be considered if vision problems start to interfere with day-to-day activities or if cataracts get in the way of treating other eye problems such as diabetic retinopathy.

Early diagnosis of glaucoma is even more important. Glaucoma is the leading cause of blindness in people over 60, but many effective treatment options are available to prevent it. These include medicated eye drops, laser surgery, and traditional surgery.

While it’s not great news that having diabetes increases your risk for vision loss, it’s so much better to have the facts than to be surprised. There are many steps you can take to help preserve your vision, and they all start with an easy annual dilated eye exam. There’s no better time than now to make an appointment.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Feb 25
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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