And, of those two million, nearly 60,000 have sight impairment due to diabetic retinopathy, a condition in which elevated blood sugar levels cause blood vessels to swell, leading to fluid leaking into the retina.

It’s the leading cause of blindness and partial sightedness for those under age 50. Nearly everyone with type 1 diabetes and 60 percent of those with type 2 diabetes develop some form of diabetic retinopathy in the first 20 years after the onset of diabetes. And, with rates of disease expected to double between 2010 and 2020, a potential crisis is at hand.

Fortunately, there are plenty of reasons for hope. Increased awareness, early diagnoses, more effective treatments , and successful disease management can preserve healthy sight.

The link between vision and diabetes

“Diabetes is first and foremost a vascular disease,” explains Dr. Dennis Ruskin, a Toronto-based optometrist and former President of the College of Optometrists of Ontario.

“The body’s vascular network brings nutrients and oxygen to all the vital tissues in the body, and diabetes is a disease that causes those blood vessels to short-circuit and leak. Eyes are especially vulnerable to damage, because they have the highest metabolic requirements of any tissue in the body, even more than the brain.”   
For those with diabetes, the first line of defence, both as prevention and as treatment when early signs of the condition appear, is proper management of blood sugar levels. Fluctuations cause damage over time to the tiny blood vessels supplying the retina. A healthy diet — low in sugar, nutrient dense, with balanced amounts of protein and carbohydrate (foods with a low glycemic index to avoid blood sugar spikes) — helps stabilize sugar levels and goes a long way in preserving sight. Add to that mix getting adequate sleep, smoking cessation, and combatting stress.

"Diabetics should be aware of the early symptoms of vision problems: dark spots, blurred vision, and large floaters (lines, dots, circles)."

Dr. Ruskin also recommends anyone with diabetes or mild diabetic retinopathy to undergo a thorough eye examination once a year that includes a look at what’s happening at the back of the eye with a test using drops that enlarge the pupil. Early detection of potential sight problems is crucial for successful treatment.

Diabetics should be aware of the early symptoms of vision problems: dark spots, blurred vision, and large floaters (lines, dots, circles). They have a higher risk of a myriad of vision problems, from detached retinas and glaucoma to cataracts and diabetic macular edema (DME). See an eye care professional right away.

New frontiers in treating vision loss

Diabetic macular edema is a serious cause of blindness in diabetics. “Once it’s detected, there is a 50 percent chance of severe vision loss if nothing is done,” says Dr. Netan Choudhry, Director, Vitreoretinal Surgery, with the Herzig Eye Institute, Toronto.

Thanks to recent progress in treatment and diagnosis, vision loss among diabetics can be prevented and addressed. To determine the degree of DME present, a digital scan of the eye using optical coherence tomography allows doctors to measure quantitatively the amount of fluid inside the retina, allowing them to determine the right course of treatment.

A decade ago, laser treatment was the go-to option, but research has found that injectable medications are more effective. “We now use lasers as second line or adjunctive therapy.”

“There have been big leaps forward in addressing DME,” says Dr. Choudhry. “A number of new medications can be injected into the eye to absorb and dissolve fluid.” New anti-VEGF drugs have been shown to be effective in reducing vision loss and may restore lost vision in some cases. “They’ve had a huge impact on patients’ quality of life. Sight loss due to diabetes is a problem that can be solved when caught early.”

A decade ago, laser treatment was the go-to option, but research has found that injectable medications are more effective. “We now use lasers as second line or adjunctive therapy,” Dr. Choudry explains.

Both Drs. Choudhry and Ruskin agree — because of advancements in treatments and diagnostic tools, no diabetic should have to lose his or her sight because of diabetes in this day and age. They both emphasize the need for improved awareness among diabetics about the real possibility of sight loss and the need for preventive action.