Diabetes and Vision
Most people with type 2 diabetes eventually experience problems with their eyesight, especially if their diabetic condition has gone unregulated. The earlier a person’s diabetes is diagnosed and controlled, the less risk he or she has of developing eyesight problems. Most eye complications from diabetes are minor; however, major problems like blindness can develop after many years if diabetes and eye problems go unchecked. According to the Journal of the American Medical Association (JAMA), “at least 40 percent of blindness in the United States is preventable or treatable with timely diagnosis and intervention.”
The most common eye complication of diabetes is retinopathy, or diseases of the retina. Diabetic retinopathy is the leading cause of acquired blindness in the United States, affecting more than four million adults over the age of 40, according to the National Institutes of Health (NIH). Type 2 diabetics can also develop other serious eye conditions such as glaucoma and/or cataracts.
What It Is
Diabetic retinopathy is caused by changes in the blood flowing to the retina, the part of your eye that receives visual information. As the blood vessels become damaged, they can leak blood or other fluids into the center of the eye, blurring vision. In severe cases, the blood vessels to the retina become completely blocked and new vessels form in their place. Those new vessels are very fragile and often leak in the same way the previous vessels had, causing problems with sight.
Diabetic retinopathy is a progressive condition that has four distinct stages:
- mild nonproliferative retinopathy (the earliest stage characterized by small, damaged and swollen blood vessels that form balloon-like groups)
- moderate nonproliferative retinopathy (characterized by some blocked blood vessels)
- severe nonproliferative retinopathy (characterized by many completely blocked blood vessels that send messages to the brain to form new vessels)
- proliferative retinopathy (the most advanced stage, when new and fragile blood vessels form and leak fluid that may cause blindness)
When a person has proliferative retinopathy, fluid from new fragile blood vessels leaks into the center of the eye (the macula) and leads to swelling beneath the macula, a condition called macular edema. About half the people who have proliferative retinopathy also have macular edema, which usually causes blindness in their center field of vision.
All diabetics are at risk for developing some form of retinopathy and/or macular edema, conditions for which there are no warning signs or pain. Eighty-four percent of type 2 diabetics will eventually develop retinopathy according to the American Academy of Ophthalmology. Type 2 diabetics with a family history of eye disease, or those who have problems with their thyroid, may be at greater risk for retinopathy. In a 2010 study published by the American Diabetes Association (ADA), type 2 diabetics with hypothyroidism were significantly more likely to develop retinopathy, including the most severe form of proliferative retinopathy that often causes blindness.
How to Prevent It
The best way to slow the progression of retinopathy is to control your blood glucose levels, blood pressure, and cholesterol. All diabetics require annual and complete eye exams as well as visits to an optometrist whenever a problem with vision becomes noticeable. Women with diabetes are also advised to see an optometrist during pregnancy. Early detection and committed follow-up care is the best way to protect your vision.
Even without symptoms, diabetics require yearly eye exams. Some of the symptoms to be aware of include: seeing “spots” or dark, cobweb-like strings or “floaters”; blurred vision; blank areas of vision; night “blindness”; and seeing colors that appear “washed out.” If you experience any of those symptoms, see an optometrist immediately. There are treatments available that can slow the progression of retinopathy as well as treatment options for those with mild to severe blindness.
What It Is
Another eye disease common in diabetics is glaucoma, especially primary-open angle glaucoma, a type seen predominantly in women with type 2 diabetes. Glaucoma is a disease that causes fluid build-up in the eye, which puts pressure on and pinches the blood vessels supplying blood to the retina and optic nerve, eventually causing damage and blindness.
According to the ADA, “People with diabetes are 40 percent more likely to suffer from glaucoma that people without diabetes.”
How to Prevent It
Like they do with retinopathy, the chances of developing glaucoma increase the longer a person with diabetes goes without treatment. Advanced age also plays a factor. Treatment for glaucoma may utilize medications to help reduce pressure in the eye. Surgery is also an option. Again, early detection results in the best possible outcome.
What It Is
Cataracts are blockages caused by damaged lens tissue in the eye. Cataracts tend to blur and cloud vision as lenses become inflexible and less transparent as they age. Although cataracts are common in the elderly, the condition is 60 percent more prevalent in people with diabetes, according to the ADA.
Cataracts also occur earlier in diabetics and may progress more quickly, especially if you smoke, drink alcohol, have uncontrolled high blood pressure, have been heavily exposed to sunlight, or have a family history of cataracts. Previous eye injuries, eye surgery, or prolonged use of corticosteroid medications may also increase your risk.
In contrast, a 2006 JAMA report noticed a reduced rate of cataract development in people being treated with statin drugs to reduce cholesterol.
How to Prevent It
While doctors do not know exactly what causes cataracts, diabetics are advised to have their eyes examined annually. Maintaining a healthy glucose level, blood pressure, and body weight, and not smoking can also lower your risks, as can wearing sunglasses with UV protection.