Eye Problems for Diabetics: Preventing Diabetic Retinopathy
Diabetes mellitus (or simply “diabetes”) is a disease characterized by chronically high blood glucose levels. The Centers for Disease Control and Prevention estimates that 30 million people have diabetes, and another 84 million have prediabetes—glucose levels that are elevated, but not high enough to be considered full-blown diabetes.
Glucose is a simple sugar that the body uses for fuel. The food you eat gets converted into glucose, which is then absorbed into the bloodstream. With the help of the hormone insulin, which is released by the pancreas, glucose enters the cells, where it provides energy necessary to function and survive.
Problems arise when the pancreas stops making enough insulin to make this process run efficiently, or when the cells stop responding to the insulin (called insulin resistance). In either scenario, levels of glucose in the bloodstream remain elevated. When this goes on endlessly and unchecked, it eventually leads to diabetes.
Diabetes is whole-body disease, affecting everything from your brain all the way down to your toes. Common complications include Alzheimer’s and cardiovascular diseases, nerve damage (neuropathy), kidney and foot problems, and eye diseases. Let’s discuss the eye-related complications further.
Diabetic Retinopathy: The Most Common Diabetic Eye Disease
Chronically high blood glucose can (and often does) damage the tiny blood vessels in the retina—the part of the eye that detects light and sends messages through the optic nerve to the brain. This condition, called retinopathy, causes blood vessels to swell and leak fluid and/or the growth of abnormal new blood vessels on the surface of the retina.
About 40% of all Americans who have diabetes also suffer from retinopathy. But experts expect that by 2050, that number will double, from 7.7 million to 14.6 million.
There are four stages:
- Nonproliferative retinopathy is the earliest stage, marked by small areas of blood vessel swelling.
- Moderate nonproliferative retinopathy, the second stage, is where the blood vessels swell and distort, sometimes losing their ability to transport blood.
- Severe nonproliferative retinopathy occurs when even more blood vessels become blocked, depriving the retina of adequate blood (and therefore oxygen) supply.
- Proliferative diabetic retinopathy is the most advanced stage. Due to the severe blockage of blood vessels and lack of oxygen, the body compensates by forming fragile new blood vessels in the retina. These blood vessels can leak blood into the vitreous (the gel-like fluid that fills the back of the eye), which results in the clouding of vision. Retinal detachment is also a real possibility, which can lead to blindness.
Diabetic retinopathy has few, if any, symptoms in the earliest stages—which is why regular eye examinations are crucial. Eye doctors who are skilled at checking for and diagnosing retinopathy can perform a variety of tests to check not only vision, but the health of every part of the eye.
In a position statement released last year by the American Diabetes Association (ADA), the authors recommend that people with type 2 diabetes undergo “an initial dilated and comprehensive eye examination by an ophthalmologist or optometrist at the time of the diabetes diagnosis. If there is no evidence of retinopathy for one or more annual eye exams, then exams every two years may be considered.”
In the latter stages of retinopathy, symptoms include changes in vision, “floaters,” and areas in the visual field that appear dark or empty. By then, it may be too late to fully restore vision.
Prevention is extremely important, as is early detection, which can help slow or stop progression of disease. According to the ADA, “regular follow-up with early detection and treatment of vision-threatening retinopathy enables the prevention of up to 98% of visual loss due to diabetic retinopathy.”
Unfortunately, people with retinopathy also need to worry about the potential for a complication of this eye disease called diabetic macular edema (DME). This is essentially a buildup of fluid in the region of the retina called the macula, which is responsible for giving us the ability to read and see things straight ahead of us. DME affects about half of retinopathy sufferers and is the most common cause of vision loss in this group.
It should also be noted that diabetes increases risk of other eye diseases such as glaucoma and cataracts. All of this underscores the need to be proactive when it comes to not only blood glucose control, but also the health of your eyes. Here’s how to do just that…
Manage Your Blood Sugar…
When it comes to blood sugar control, many doctors prescribe oral drugs or injectable insulin. But in many cases, lifestyle changes and certain nutritional supplements are all you need to get glucose levels back into the healthy range.
There are many nutrients that can help support and maintain blood sugar balance. But berberine is at the top of the list.
Berberine is a phytonutrient found in many different plants including goldenseal and Oregon grape. Most notably, it has a profound effect on AMP-activated protein kinase (AMPK), a protein involved in metabolism. Activation of AMPK promotes the uptake of glucose in the cells and increases insulin sensitivity. One study showed that berberine performed every bit as well as the popular oral diabetes drug metformin when it came to controlling blood sugar and cholesterol and triglyceride levels. The recommended dosage is 1,000-1,500 mg daily, in divided doses.
The trace mineral chromium is another excellent natural blood sugar modulator. In one study, 180 people with diabetes were divided into three groups. Two groups took chromium (100 mcg or 500 mcg, twice daily) and the third took a placebo.
After four months, those who took the chromium showed significant improvement in many diabetes markers. The researchers concluded, “These data demonstrate that supplemental chromium had significant beneficial effects on HbA1c [hemoglobin A1c], glucose, insulin, and cholesterol variables in subjects with type 2 diabetes.”
The recommended dosage for chromium is up to 400 mcg daily.
…And Protect Your Eyes
Along with controlling your blood sugar, it’s important to feed your eyes the nutrients they need to stay healthy.
According to the Age-Related Eye Disease Study (AREDS), a major study sponsored by the National Eye Institute, vitamin C, vitamin E, beta-carotene, and zinc were named top players in protecting the eyes from a variety of diseases. In the follow-up AREDS2 study, though, two new superstars were unveiled: lutein and zeaxanthin.
Of all the antioxidant carotenoids, lutein and zeaxanthin are the only ones that accumulate in the retina. They act like sunscreen, blocking out harmful blue light and protecting against oxidative stress. Lutein has also been shown to reduce inflammation and eye fatigue.
You can find many eye-health supplements that contain these two nutrients, but if you decide to take them individually, the recommended dosage is 20 mg of lutein and 4 mg of zeaxanthin daily.
- National Eye Institute. Diabetic Retinopathy Statistics and Data. Last accessed October 29, 2018.
- Solomon SD, et al. Diabetic retinopathy: A position statement by the American Diabetes Association. Diabetes Care.2017 Mar; 40(3): 412-8. Last accessed October 29, 2018.
- Yin J, Xing H, Ye J. Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism. 2008 May;57(5):712-7. Last accessed October 29, 2018.
- Anderson RA. Elevated intakes of supplemental chromium improve glucose and insulin variables in individuals with type 2 diabetes. Diabetes. 1997 Nov;46(11):1786-91. Last accessed October 29, 2018.
- National Eye Institute. Age-Related Eye Disease Study Results. Last accessed October 29, 2018.
- National Eye Institute Press RNIH study provides clarity on supplements for protection against blinding eye disease. May 5, 2013. Last accessed October 29, 2018.
Last Updated: January 9, 2020
Originally Published: November 13, 2018