Diabetic Eye Problems: How High Blood Sugar Can Affect Your Vision

Diabetes puts you at risk for vision problems. Here’s what you need to know to protect your eye health.

An old woman with glasses smiling into the camera

You may have heard that complications from diabetes are among the leading causes of vision loss. That’s true. Left uncontrolled, diabetes can seriously harm your eyes. But losing your eyesight is certainly not a given.

“The reality is that many diabetic eye problems can be treated and managed, as long as you catch it early and follow the treatment plan,” says Rahul N. Khurana, M.D., a vitreoretinal surgeon with Northern California Retina Vitreous Associates Medical Group and clinical spokesperson for the American Academy of Ophthalmology. 

Dr. Khurana’s best advice? Keep up with your diabetes treatment plan as outlined by your doctor—and make getting regular eye exams a priority.

Those yearly checkups, he says, will help your eye doctor spot three of the most common types of diabetic eye problems:

Diabetic Eye Problem #1: Nonproliferative Diabetic Retinopathy

According to the American Diabetes Association, this mouthful of a condition is the most common form of diabetic retinopathy, which is the umbrella term for eye problems that target the retina. 

The Centers for Disease Control and Prevention reports that by 2050 the number of Americans with diabetic retinopathy is expected to climb to 14.6 million—nearly twice what it is today. 

As a quick reminder, the retina lines the back of the eye and is attached to the optic nerve. Its job is to take in light from the eye’s lens and package it into a signal that can be ferried via the optic nerve to the brain for visual recognition.

In other words, it’s pretty important.

Uncontrolled high blood sugar can cause the tiny blood vessels in the retina to swell, weaken, and leak, which can chip away at healthy vision. Some people may have no symptoms at all, meaning only an eye doctor can pick up the changes taking place. Others might see an increase in floaters or notice that their vision is slightly off, or they may experience other temporary vision changes.

How it’s treated: In this early stage, your health care team will likely focus on better blood sugar control to slow, stop, or reverse any vision changes. They’ll also probably recommend that you see your eye doctor more often to monitor the changes. Keeping blood pressure in check is also important to help stop any progression. 

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Diabetic Eye Problem #2: Diabetic Macular Edema 

One of the more serious complications for people with nonproliferative diabetic retinopathy is the swelling of the macula—the part of the retina that’s responsible for central vision.

The swelling is called diabetic macular edema, or DME, and it occurs when high blood sugar levels weaken blood vessels to the point that they burst. The fluid that leaks out and into the macula is a combination of blood and a mixture of cells, protein, and solid materials called exudate.

Not surprisingly, the swelling from the fluid makes it next to impossible for your eyes to focus on anything clearly. In fact, DME is the most common cause of vision loss in people with diabetes. 

How it’s treated: Lowering blood sugar and blood pressure can help stop DME from advancing. There are also medications available, including corticosteroids and medicines that keep abnormal blood vessels from forming in the first place. Many times, these medicines can reduce swelling and even reverse the damage. 

If you’re diagnosed with DME, don’t put off starting treatment. Researchers presenting at the American Academy of Ophthalmology Annual Meeting in 2017 reported that most patients (up to 60 percent) who are newly diagnosed with this condition either do not receive treatment right away or are not given the recommended dosages of sight-saving medications.

If you’re having trouble following your recommended treatment plan (regarding any aspect of your health, not just your eyes), talk to your health care team, who may be able to connect you with helpful resources such as financial aid or transportation. 

Diabetic Eye Problem #3: Proliferative Diabetic Retinopathy

This is the more advanced stage of diabetic retinopathy. About 5 percent of people with nonproliferative diabetic retinopathy will develop proliferative diabetic retinopathy (PDR) in 5 years.

That number rises to 38 percent among high-risk individuals, such as those who have trouble getting and keeping blood sugar in the healthy range. Age, gender, blood pressure, and number of years with diabetes play a role too. 

In PDR, blood vessel damage in the eye starves the retina of oxygen and nutrients. As a workaround, the retina tries to grow new vessels, but they too are weak and leaky. They often bleed into the fluid inside the eye, causing floaters, which can block some or all vision.

Another problem that can develop at this stage is neovascularization of the iris. It's marked by a tangle of fine (and very fragile) blood vessels that appear on the surface of the iris, near the pupil.

How it’s treated: If lifestyle changes and medications are not working, injections or laser or physical surgery may be used to remove some of the blood vessels and stop them from leaking blood and fluid. 

Surgery can also be used to take out scar tissue, which can help prevent another problem called retinal detachment, in which the retina pulls away from the back of the eye. If the retina does tear or pull away, another type of surgery can be done to repair it.

3 Other Potential Diabetic Eye Problems

The following eye conditions can happen to anyone, but they are more common in people with diabetes:

  • Cataracts: A clouding of the eye’s lens
  • Glaucoma: Damage to the optic nerve 
  • Retinal vein occlusion: A blockage in one of the retinal veins 

The American Diabetes Association recommends that everyone with diabetes see an eye doctor at least once a year—but check with your doctor for more specific advice.

Diabetes and Your Eyes: How to Protect Your Vision