Diabetes causes a wide range of complications, affecting different organs and functions in the body. One of the organs affected by this chronic disease is the eyes.
Not only that can deter our vision, but diabetes can cause a host of eye problems. Some of them are cataracts, diabetic macular edema (DME), glaucoma, diabetic retinopathy, all of which can lead to severe vision loss or blindness.
But, the most common diabetic eye disease is diabetic neuropathy.
How Diabetes Affects the Eyes
Here’s a word or two about each diabetic eye problem.
Diabetic Eye Diseases
- Diabetic Retinopathy – This eye condition affects blood vessels in the retina – a light-sensitive tissue found at the back of the eye. It’s the #1 cause of loss of vision among those with diabetes.
- Diabetic macular edema (DME) – A swelling in the macula that occurs as a result of diabetic retinopathy.
- Cataract – This eye condition is clouding of the eye’s lens. Those with diabetes have a 2 to 5 times higher risk of getting cataracts than those without diabetes.
- Glaucoma – A host of conditions that damage the optic nerve of the eye which connects to the brain. There are several types of glaucoma, some of which are related to high eye pressure. Diabetes doubles the risk of glaucoma in adult people.
Each diabetic eye disease can lead to severe vision impairment and blindness.
What Causes Diabetic Retinopathy?
Having high blood sugar levels almost all the time can damage tiny blood vessels in the retina, leading to the most common diabetic eye disease – diabetic retinopathy. The retina converts the light into a signal which is then transmitted to the brain by the optic nerve.
This eye condition distorts the vision by causing blood vessels in the retina to bleed or leak fluid. The late stage of diabetic retinopathy causes the proliferation of new abnormal blood vessels on the retina’s surface, leading to cell loss and scarring in the retina.
About half of diabetic retinopathy patients will develop diabetic macular edema at any stage of the disease.
4 Stages of Diabetic Retinopathy
1. Mild Nonproliferative Retinopathy – The earliest stage of this eye condition causes balloon-like swelling in the tiny blood vessels in the retina, called microaneurysms. These swollen areas can leak fluid into the retina.
2. Moderate Nonproliferative Retinopathy – In this stage of diabetic retinopathy, there’s swelling and distortion of the blood vessels which nourish the retina. What’s more, these blood vessels can lose their ability to transport blood.
So, all of this leads to changes in the retina appearance, contributing to diabetic macular edema.
3. Severe Nonproliferative Retinopathy – Blockage of more blood vessels which doesn’t allow the necessary blood supply to all parts of the retina. These blood-deprived areas of the retina secrete growth factors that cause the growth of new blood vessels.
4. Proliferative Diabetic Retinopathy (PDR) – Since at this stage the retina secretes growth factors, new blood vessels proliferate at the inner retinal surface and into the fluid that fills the eye, called the vitreous gel. These new blood vessels can easily leak and bleed as they are very fragile.
If there’s scar tissue as well, it can pull the retina away from the underlying tissue, causing retinal detachment. This, in turn, can lead to permanent loss of vision.
Who Is at Risk for Diabetic Retinopathy?
All people with diabetes, regardless of the type, have an increased risk of developing diabetic retinopathy. The longer they have diabetes, even gestational, the higher the risk.
According to statistics, 40-45% of all diabetics in America have some stage of diabetic retinopathy, even though half of them are unaware of it. Pregnant women with diabetes or those who develop it during pregnancy can have quick onset or worsen of this eye problem.
Symptoms of Diabetic Retinopathy and Diabetic Macular Edema
Even though diabetic retinopathy doesn’t show any symptoms at the early stages, it can easily progress until noticing the problems with vision. You might notice “floating” spots caused by the bleeding from new abnormal blood vessels in the retina.
The spots can disappear on their own, but sometimes if not treated on time, it can lead to another bleeding, raising the chances of permanent vision loss. In the case of diabetic macular edema, the vision will get blurred.
How to Protect Vision
Even though lost vision caused by diabetic retinopathy is usually irreversible, blindness can be prevented by 95% with early detection and treatment. This condition has no symptoms at first, so it’s best to get a comprehensive dilated eye exam once per year.
However, in the case of diabetic retinopathy, it’s best to do more than just one eye exam. Also, pregnant women with diabetes should also make a comprehensive dilated eye exam early in their pregnancy. They might need to do more eye exams during their pregnancy.
The Diabetes Control and Complications Trial and other studies showed that if people have control over their diabetes, they could prevent and slow down the worsening of diabetic retinopathy.
Other studies showed that controlling increased cholesterol and blood pressure levels can lower the chances of vision loss in those with diabetes.
Often, diabetic retinopathy treatment is postponed until it begins to progress to proliferative diabetic retinopathy, or when diabetic macular edema occurs. As diabetic retinopathy progresses, people need more frequent comprehensive dilated eye exams.
Those with severe nonproliferative diabetic retinopathy have more chances of developing proliferative diabetic retinopathy, so they should do such an eye exam every two to four months.
More Tips to Protect Eyes
People with diabetes should control their blood sugar levels, but also their cholesterol and blood pressure in order to protect their vision. Here are some things people can do to prevent diabetic retinopathy and other diabetic eye diseases from developing:
- Telling the diabetes care team about any problem or change in vision
- Maintaining a healthy weight, and losing some pounds if necessary (for overweight and obese people)
- Staying fit through regular physical activity
- Having a healthy, balanced diet
- Quitting the habit of smoking
- Following your prescribed medication plan
Source Diabetes | National Eye Institute
