When Diabetes Goes For The Eyes
It’s not a myth: diabetes really can affect eye health. Blood glucose, cholesterol levels and blood pressure are all variables that can cause serious long-term damage and, in the worst-case scenario, blindness. That’s why it’s so important to discuss this issue and focus on prevention. Here’s a quick overview to help you see the big picture.
Glaucoma occurs when pressure builds up in the eye and damages the optic nerve and blood vessels. This disease causes a gradual loss of vision, starting with the periphery, and can lead to blindness if it isn’t treated. The big problem with glaucoma is that it often shows no symptoms for many years.
Cataracts are often associated with age, but the effect of diabetes can cause them to appear much earlier and develop more rapidly. They manifest in the lens becoming partly or fully opaque, which leads to a progressive loss of vision with symptoms such as sensitivity to light and blurred or hazy vision.
Around 2 million Canadians—the majority of diagnosed diabetics—will at some point suffer from some form of diabetic retinopathy. This term refers to any disorder of the retina caused by diabetes.
In the early stages, known as “non-proliferative retinopathy” or “background retinopathy,” retinal blood vessels weaken and cause small hemorrhages in the eye, often resulting in swelling and impaired vision.
If the problem is not treated, it eventually degenerates into proliferative retinopathy. As blood circulation contracts, some vessels in the retina are deprived of oxygen and die. New vessels form, but they are abnormal and extremely fragile. They burst easily, sending blood into the retina and the vitreous, which causes floaters and a decrease in vision. This phenomenon occurs repeatedly over many years, eventually leading to blindness. In addition to the loss of vision, symptoms often include seeing light flashes or black spots and having trouble discerning colours.
Macular edema is a complication of retinopathy stemming from the thickening of the macula, the part of the retina that’s responsible for detailed, central vision. Half of people with proliferative retinopathy also suffer from macular edema.
Beyond just diabetes, smoking, high blood pressure, pregnancy, hyperglycemia and high cholesterol may trigger or worsen eye problems.
Eye diseases can wreak havoc on someone’s life, but fortunately, they can usually be prevented or treated by taking appropriate measures:
- Visit your optometrist once a year to detect early signs of glaucoma, cataracts, retinopathy and macular edema.
- See your physician regularly and follow your treatment plan (diet, exercise, medication, etc.).
- Keep your blood glucose at optimal levels. The same advice goes for blood pressure and cholesterol.
- Monitor your A1c test results (blood glucose over two or three months). Ideally, you would shoot for 7.0 or less, but your target level may differ depending on your health care professional’s recommendations.
Who should get an eye exam?
Anyone with type 1 diabetes from the age of 15 or 5 years after diagnosis, anyone with type 2 diabetes at the time they are diagnosed, and any woman with type 1 or 2 diabetes before getting pregnant. After that, a yearly eye examination is recommended.
Since many eye problems are initially asymptomatic, prevention is your best ally to protect your ocular health—and continue seeing life in the best possible light.
American Diabetes Association, “Eye Complications”: http://www.diabetes.org/living-with-diabetes/complications/eye-complications/?referrer=https://www.google.ca/. Accessed February 1, 2017.
Canadian Diabetes Association, “Eye Damage (Diabetic Retinopathy)”: https://www.diabetes.ca/diabetes-and-you/complications/eye-damage-diabetic-retinopathy. Accessed February 1, 2017.
Canadian Association of Optometrists, “The Link Between Diabetes and Your Eyes”: https://opto.ca/health-library/the-link-between-diabetes-and-your-eyes. Accessed February 1, 2017.
Diabetes Québec, “Le diabète et la santé des yeux”: http://www.diabete.qc.ca/medias/upload/files/depliant_sante%20des%20yeux%281%29.pdf. Accessed February 1, 2017.
Diabetes Québec, “Diabetes and the Eye”: http://www.diabete.qc.ca/en/understand-diabetes/all-about-diabetes/complications/le-diabete-et-loeil. Accessed February 1, 2017.