Diabetes is a common cause of vision loss due to diabetic retinopathy, glaucoma, and cataracts. Diabetics are 40% more likely to have glaucoma, and 60% more likely to have cataracts, per the American Diabetes Association. If left unchecked, vision loss due to diabetes is irreversible. The National Eye Institute (NEI), however, states that early detection and treatment can reduce one’s risk of blindness by 95%. Here are seven facts about diabetes-related vision loss:
1. Diabetes Damages the Retina
When light passes through the eye, it hits a layer of tissue called the retina. Cells here are sensitive to light and pass it on to the optic nerve. The retina has small blood vessels that can be damaged by chronically high blood sugar levels or high blood pressure. Diabetic retinopathy is when these vessels start to leak, or hemorrhage, distorting one’s vision.
There are four stages of this condition:
- Mild non-proliferative retinopathy: Micro aneurysms in the retina cause some fluid to leak out of small vessels.
- Moderate non-proliferative retinopathy: A swelling and distortion of the retina’s blood vessels, which may disrupt blood flow in the retina.
- Severe non-proliferative retinopathy: Many blood vessels are blocked, depriving the retina of blood, and triggering the release of growth factors.
- Proliferative diabetic retinopathy: New vessels grow along the inside of the retina and into the fluid within the eye; they’re more prone to leak, and scar tissue may form, causing the retina to detach from the underlying eye tissue. This can cause a permanent loss of vision.
There are usually no symptoms during the early stages of diabetic retinopathy and is one of the most common causes of diabetes sight loss.
2. Diabetes Causes Blurry Vision
Diabetic macular edema (DME) is a build-up of fluid in the macula, a part of the eye responsible for seeing straight ahead. It occurs in half of people with diabetic retinopathy, at any stage of the condition, according to the American Academy of Ophthalmology’s Facts About Diabetic Eye Disease. Blurred vision is the primary symptom.
3. Diabetic Retinopathy and DME Can Be Easily Detected
These diabetic eye issues can be found during a routine eye exam. An optometrist or ophthalmologist will conduct a dilated eye exam, where they test visual acuity to measure distance vision, and tonometry to measure internal eye pressure. By dilating the pupil, a physician can visually examine the retina and other structures inside the eye. They can identify changes in blood vessels, leaky vessels or fatty deposits, macula swelling, and nerve tissue damage.
4. Diabetic Retinopathy Is Treatable
If someone is diagnosed with diabetic retinopathy, there are treatments available to help prevent blindness, including:
- Photocoagulation: A laser is used to burn and seal blood vessels to stop blood from leaking and the vessels from growing.
- Scatter photocoagulation: The laser is focused in a polka-dot pattern by an eye care professional. Thousands of tiny burns are made during two or more treatments to shrink abnormal blood vessels.
- Focal photocoagulation: A laser is aimed at the macula to treat leaky blood vessels. The procedure keeps blurry vision and other effects of macular edema from getting worse.
- Vitrectomy: A surgical procedure to remove scar tissue and the vitreous gel inside the eye. Used to treat severe bleeding, it can restore vision and be used to reattach the retina.
To treat DME, therapies include:
- Anti-VEGF injection therapy: Targets vascular endothelial growth factor (VEGF), a protein that causes blood vessel growth. This treatment can reverse the growth of abnormal vessels and reduce retinal fluid.
- Corticosteroids: Injecting or implanting corticosteroids into the eye can suppress DME, but can increase one’s glaucoma and cataract risk.
- Macular laser surgery: Focusing a laser at the center of the macula can slow fluid leakage, reduce retinal swelling, and supplement anti-VEGF therapy.
5. The Longer One Has Diabetes, The Higher Their Risk
The longer a person has diabetes, the higher their risk of getting diabetic retinopathy. With type 1 diabetes, the odds are low unless they’ve been diabetic for five years or more. They’re less likely to develop retinopathy if blood sugar is controlled with insulin. Type 2 diabetes can lead to
eye problems sooner, but can be slowed down by controlling sugar intake, blood pressure, and cholesterol.
6. Diabetics Have a Higher Risk of Glaucoma
A buildup of pressure inside the eye, glaucoma is a group of diseases. Secondary glaucoma is a common eye problem associated with diabetes and includes a severe form called neovascular glaucoma. About one-third of these cases involve people with diabetes, according to the American Academy of Ophthalmology. Pressure in the eye builds up in the anterior chamber, affecting the flow of fluid in and out of this chamber. In the case of open-angle glaucoma, the fluid drains too slowly, and the resulting pressure can damage the optic nerve.
Warning signs for glaucoma include eye pain, halos around lights, watery eyes, blurred vision, and headaches. An eye exam will detect the disease at any stage. Glaucoma is often treated and controlled with specialized eyedrops.
7. Diabetic Eye Issues Can Be Prevented
If conditions such as diabetic retinopathy are detected early, they can be treated. An annual dilated eye exam will find signs of the condition, even if there are no symptoms. Research has shown controlling diabetes slows down the onset and progression of retinopathy, especially if blood glucose levels are well-managed. If a severe case is suspected, a physician may perform a fluorescein angiogram. A dye injected into the blood helps to view leaky or damaged blood vessels in the eye.