How diabetes affects the eyes

By DR MAXWELL ADEYEMI

People with diabetes are more likely to get eye diseases than people without diabetes. As the diseases progresses, diabetic eye disease and other ocular complications become more evident, especially if the blood sugar is not properly managed.

Diabetic eye diseases include diabetic retinopathy, diabetic macular edema, cataracts, and glaucoma. Over time, diabetes can cause damage to your eyes that can lead to poor vision or even blindness. Often, there are no warning signs of diabetic eye disease or vision loss when damage first develops. A full, dilated eye exam helps your doctor find and treat eye problems early, often before much vision loss can occur.

How diabetes affects the eyes

Temporary blurry vision when the blood sugar is too high, but patients are not likely to have vision loss in the short term from high blood glucose. People sometimes have blurry vision for a few days or weeks when their blood sugar is elevated. This can change fluid levels or cause swelling in the tissues of your eyes that help the eyes to focus. This type of blurry vision is temporary and goes away when the glucose level gets closer to normal.

Long term eye damage occurs if the blood glucose stays high over time. This can damage the tiny blood vessels at the back of the eyes. This damage can begin during pre diabetes, when blood glucose is higher than normal, but not high enough to result in a diabetes diagnosis.

Damaged blood vessels may leak fluid and cause swelling. New, weak blood vessels may also begin to grow. These blood vessels can bleed into the middle part of the eye, lead to scarring, or cause dangerously high pressure inside the eye.

The major eye diseases that can threaten the eyes in diabetics are:

Diabetic retinopathy

The retina is the inner lining at the back of each eye. The retina senses light and turns it into signals that the brain decodes, so we can see the world around us. Damaged blood vessels can harm the retina, causing a disease called diabetic retinopathy. In early diabetic retinopathy, blood vessels can weaken, bulge, or leak into the retina. This stage is called non-proliferative diabetic retinopathy. If the disease gets worse, some blood vessels close off, which causes new blood vessels to grow, or proliferate, on the surface of the retina. This stage is called proliferative diabetic retinopathy. These abnormal new blood vessels can lead to serious vision problems.

Diabetic macular edema

The part of the retina that we need for reading, driving, and seeing faces is called the macula. Diabetes can lead to swelling in the macula, which is called diabetic macular edema. Over time, this disease can destroy the sharp vision in this part of the eye, leading to partial vision loss or blindness. Macular edema usually develops in people who already have other signs of diabetic retinopathy.

Glaucoma

Glaucoma is a group of eye diseases that can damage the optic nerve, the bundle of nerves that connects the eye to the brain. Diabetes doubles the chances of having glaucoma, which can lead to vision loss and blindness if not treated early.

Cataracts

The lenses within the eyes are clear structures that help provide sharp vision, but they tend to become cloudy as we age. People with diabetes are more likely to develop cloudy lenses, called cataracts. People with diabetes can develop cataracts at an earlier age than people without diabetes. High glucose levels cause deposits to build up in the lenses of the eyes and cause cataract.

Risks

Anyone with diabetes can develop diabetic eye diseases. Your risk is greater with:

-high blood glucose that is not treated or poorly controlled.

-high blood pressure that is not treated

-High blood cholesterol and smoking may also raise your risk for diabetic eye diseases.

-If you have diabetes and become pregnant, you can develop eye problems very quickly during your pregnancy. If you already have some diabetic retinopathy, it can get worse during pregnancy.

-Your chances of developing diabetic eye diseases increase the longer you have diabetes.

Symptoms of diabetic eye disease

When symptoms do occur, they may include:

• blurry or wavy vision

• frequently changing vision

• dark areas or vision loss

• poor colour vision

• spots or dark strings (also called floaters)

• flashes of light

Diagnosis

Having a full, dilated eye exam is the best way to check for eye problems from diabetes. Your eye specialist will conduct this test to thoroughly examine your eyes.

Your doctor will also test your vision and measure the pressure in your eyes.

Retinal photography can also be taken which can be examined by trained health personnel.

Eye exam guidelines for diabetes

• Type 1: Yearly eye exams should start within five years of diagnosis.

• Type 2: Yearly eye exams should start right after diagnosis.

• Pregnancy: Women with type 1 and type 2 diabetes need an eye exam before pregnancy or within the first three months. This should be repeated later in the pregnancy and until at least one-year post delivery.

Treatment

Your health care provider may recommend having eye exams more often than once a year, along with management of your diabetes, which include your A1c, blood pressure, and cholesterol; and quitting smoking. Management of blood glucose can help prevent diabetic eye disease and keep it from getting worse.

Advanced diabetic eye disease may be treated with:

Medicine such as anti-VEGF medicines which blocks the growth of abnormal vessels in the eye.

Laser treatments which can keep eye disease from getting worse.

Surgery such as vitrectomy and cataract lens surgery may be indicated for specific eye conditions.

Prevention

To prevent diabetic eye disease, or to keep it from getting worse:

-Manage your blood sugar effectively

-Manage your HbA1c

-Control your blood pressure.

-Maintain normal cholesterol

-Quit smoking

-Have a dilated eye exam at least once a year

Early and regular screening for diabetic eye disease is vital to avoid this complication.

Contact Dr Maxwell on 363-1807 or 757-5411.