Diabetes is a disease that affects the entire body--and that includes the eyes.
"Blurry vision, seeing spots or experiencing pressure or pain in the eye are all symptoms of problems diabetics may be prone to," says William David Boothe, MD, an ophthalmologist at Covenant Health. "However, because these symptoms often don't appear until an eye problem is in an advanced stage, it's important for people to know what these diseases are and how to lower their risk."
Over time, high blood sugar wreaks havoc with the blood vessels in the eyes. "Diabetic retinopathy moves through four stages as the blood vessels swell and have trouble getting enough oxygen. New vessels will start to grow in response, but those are weak and can burst or leak," Dr. Boothe says. "In the final stage, there is a great danger that the retina--the tissues in the back of the eye--will detach and cause profound vision loss." Diabetic retinopathy is the most common culprit when it comes to diabetes-related vision loss. Once it's diagnosed, it may be treated with laser therapy or medication. In severe cases, if blood leaks into the eyes' vitreous gel, that substance may become clouded and removed via a surgery called a vitrectomy.
Diabetic macular edema
Diabetic retinopathy can lead to this disease, which affects the macula, an area in the retina that provides the eyes with the sharpness needed to clearly see details. "Fluid leaking from the eyes' blood vessels can cause the macula to swell, which can affect vision," Dr. Boothe says. About half of the people with diabetic retinopathy will also get diabetic macular edema, which is treated with drugs such as corticosteroids or macular laser surgery.
While this is an eye problem that can affect anyone, diabetic adults are up to five times as likely to get cataracts compared to people without diabetes. Because the cataract clouds the lens of the eye, vision can become blurry. "During the early stages, people with cataracts may need to shield their eyes from bright light with sunglasses, or glasses with a protective, anti-glare coating," Dr. Boothe says. "But if the disease progresses, the lens of the eye may have to be removed and replaced. However, lens removal can increase problems with retinopathy."
Diabetic adults have almost double the risk for glaucoma than non-diabetics. That's because the diseases that fall under the glaucoma umbrella are a result of increased pressure in the eye, which can be caused by swollen or abnormal blood vessels affected by diabetic retinopathy. "Glaucoma can impair the optic nerve, which runs from the eyes to the brain; that can cause severe vision loss if not treated with eye drops, medication or surgery," Dr. Boothe says.
What to do
For all of these eye diseases, the earlier the treatment, the better. To lower the risk, or prevent vision loss, Dr. Boothe suggests:
- An annual eye exam. "Everyone with diabetes needs to stay on top of their eye health and get a thorough checkup at least once a year, or more frequently if recommended by their physician," Dr. Boothe says. "The exam should include a basic vision test with an eye chart, pupil dilation for a more thorough examination of the eye for disease, and tonometry, which tests the pressure in the eyes for glaucoma. A more advanced test is fluorescein angiography, which uses dye to track blood flow in the retina. Spotting a problem early, and getting it treated, can reduce vision loss."
- Healthy blood pressure levels. "High blood pressure takes its toll on the body's blood vessels, and those in the eyes are no different; it can lead to retinopathy," Dr. Boothe says. "Because people with diabetes have an increased risk for high blood pressure, they should monitor it often, according to doctor's instructions, and take any prescribed medication."
- Meeting blood sugar targets. "The longer that blood sugar levels are high, the more likely they will cause damage to the eyes," Dr. Boothe says. "It's important to monitor blood sugar, and keep it under control with a healthy diet and plenty of exercise."
This information is not intended as a substitute for professional medical care. Always follow your health care professional's instructions.