November is Diabetic Eye Disease Month, drawing attention to this chronic disease, and specifically how it affects vision and eye health, an aspect of diabetes that may not be discussed as often as perhaps it should.

What is Diabetes?

Diabetes is a disease that revolves around the body’s insulin function. Insulin is a hormone the pancreas produces that regulates the amount of sugar (glucose) in your blood. Your body’s function depends on the careful regulation of your blood sugar levels, which your body tends to do on its own, but too much sugar in your blood can cause all kinds of not-fun issues with your organs. Insulin is the key to turning sugar into energy, which puts it to better use than wreaking havoc on your insides. 

Diabetic Eyes

Changes in blood sugar levels can have a profound effect on the eyes. Diabetic patients are more likely to witness things like floaters or dark spots in their vision, blurry vision or vision that alternates between blurry and clear, unreliable night vision, and even loss of colour awareness. All of these directly affect a patient’s ability to move throughout their day, travel at night, and enjoy the full quality of their life. Diabetic vision symptoms normally affect both eyes simultaneously.

In Ontario, all diabetic patients with a valid Ontario Health Card are covered by the Ontario Health Insurance Plan (OHIP) once every 12 months. This is because they are always at risk of developing serious vision issues as long as they have diabetes. With proper blood sugar regulation and regular trips to the eye doctor, the effect diabetes has on a patient’s eyes can be significantly decreased.

Unique Vision Risks for Diabetics

The back of our eye is where our retina is located, a sensitive layer of cells and photoreceptors that take what we see and transmit it along neuropathways to our brain, where we’re able to form a picture of what we’re seeing. Our retina is directly impacted by the effects of diabetes.

Diabetic Retinopathy is a serious condition that occurs when high blood sugar levels cause the blood vessels in our eyes (and our sensitive retinas) to swell or even close off. It can also lead to growth of abnormal blood vessels that may seep fluid and blood into the eye. There are two types of Diabetic Retinopathy:

Non-Proliferative Diabetic Retinopathy

This form of Diabetic Retinopathy is more common amongst diabetic patients. It occurs when the aforementioned leaky blood vessels cause the retina to swell, or the blood vessels themselves may close off entirely. When this occurs, blood can’t reach the macula (the part of the retina responsible for our central vision and ability to discern finer details), leading to a condition called macular ischemia. In other cases, the macula may swell along with the retina, leading to diabetic macular edema, the most common reason diabetic patients begin to lose their vision. 

Proliferative Diabetic Retinopathy

This is the more advanced stage of Diabetic Retinopathy. Patients reach this stage when they show signs of neovascularization, meaning new blood vessels have begun to grow within the retina. These new blood vessels can be abnormal and quite fragile. They tend to bleed into the vitreous of the eye (the clear jelly-like fluid that fills the eyeball). A small amount of blood spots can lead to “floaters” in the eyes, while a lot of bleeding can really block off a patient’s vision (sometimes referred to as a vitreous haemorrhage). 

The other risk associated with these new blood vessels is that they may cause scar tissue to form within the eyes, which significantly increases the patient’s risk of macular complications or a complete retinal detachment. 

Did You Know?

The human eye is the only place on the body where blood vessels can be clearly viewed, allowing doctors to assess your cardiovascular and systemic health without slicing you open. 🎉

Giving the Best Vision Possible

We encourage all our diabetic patients to take full advantage of their OHIP coverage, which allows for one (1) full exam per 12 months. It is important that patients keep up with their appointments to ensure proper monitoring of their vision and overall ocular health. 

Optical Coherence Tomography (OCT) is the gold standard for diagnostic retinal imaging. It provides highly detailed images of the layers behind the retina to help detect any changes or abnormalities. The process is quick and painless, a few bright flashes of light like a camera flash capturing these details as it takes a series of images to get a detailed view of individual structures within the retina, including close details of the macula. These images are one of the best ways to monitor eye health and track any changes or developments that may occur, especially as a result of existing conditions such as diabetes. 

Dilation drops are given to open the pupil and allow more light to reach the back of the eye, giving the optometrist or ophthalmologist a better view of the retina and any possible concerns. Dilation drops aren’t everyone’s favourite, but they not only allow the exam itself to be as thorough as possible, it also opens the eye to allow for the best possible imaging for OCT. The effects of the drops include blurred near vision and increased light sensitivity, but they dissipate after a few hours. 

Following a Diabetic Eye Exam, we put together an Ocular Diabetic Report outlining the exam’s findings as they relate to the patient’s diabetes and send it to their family doctor for review. This ensures that a diabetic patient’s health care team are all on the same page and can work together to offer the best care for them, and ensure they maintain their vision as best as possible.

Final Thoughts

Diabetes is estimated to affect more than 11 million Canadians each year (this includes diabetes and pre-diabetes, which – if left untreated – can develop into type 2 diabetes), with Ontario in the lead. It’s imperative that diabetic patients don’t allow the fact that diabetes has become more common to mean it’s not something to worry about. Diabetes carries serious health complications, including risks to vision and overall ocular health. 

If you’ve been diagnosed with diabetes and haven’t had your eyes checked within the last year, speak to your family doctor about a referral, or visit our booking page here, to get yourself on track to maintaining the best vision health you can.

My maternal grandmother was diagnosed with diabetes and she took her practice of monitoring her blood sugar very seriously. She only required glasses for reading, and was able to watch her grandchildren grow into the people she’d always encouraged them to be. 

We’re happy to help you do the same.

Wishing you all the best in wherever your path takes you today,

Sydney Gallant, CCOA