Doctors answer the most frequently asked questions:
In Canada, 1.8 million people have type 1 or type 2 diabetes. diabetic retinopathy is an eye complication of diabetes that affects 99 percent of people with type 2 diabetes and 60 percent of those with type 1 diabetes within 20 years of the onset of diabetes. Diabetic retinopathy is one of the leading causes of blindness in industrialized countries.
Diabetic retinopathy is a painless disease. Perceptible symptoms (the main
one is vision loss) may not appear until late in the progression
of the disease, when complications.
Diabetic retinopathy, as its name indicates, is caused by diabetes.
Hyperglycemia (high blood sugar) can cause the walls
of the tiny blood vessels in the retina (retinal capillaries) to
gradually become fragile, swell and leak fluid (plasma) and
The progression of diabetic retinopathy varies. It can, however, progress more quickly in case of poor blood sugar control, high blood pressure, pregnancy, puberty or cataract surgery.
There are two forms of diabetic retinopathy: nonproliferative diabetic retinopathy and proliferative diabetic retinopathy. In nonproliferative diabetic retinopathy, the blood vessels, which have become fragile due to an excess of blood sugar, start to leak fluid (plasma) and blood, and this can cause the retina to swell. In proliferative diabetic retinopathy (an aggravation of nonproliferative diabetic retinopathy) small abnormal blood vessels form, invading the retina. These blood vessels can break, causing hemorrhages.
Macular edema is a complication of nonproliferative as well as proliferative diabetic retinopathy (and of other diseases, particularly vein occlusions). It is a swelling of the macula (the central area of the retina) caused by leakage of fluid and blood through the walls of dilated blood vessels. Macular edema is the most common cause of vision loss.
As diabetic retinopathy is a disease that remains asymptomatic
until a very advanced stage, the importance of regular eye
examinations cannot be overemphasized, especially for people
who are diabetic. An optometrist or ophthalmologist can
detect DR by examining the back of the eye (ocular fundus
examination), which will also indicate the type and severity of
Yes, but only in very rare cases. Diabetic retinopathy can cause blindness at a
very advanced stage if necessary measures (screening, prevention
and treatment) have not been taken in time.
Yes. Vision loss can usually be prevented in people with diabetes
by regular eye examinations throughout their lifetime.
In addition, the better the diabetes control, the better the
chances of preventing complications that could lead to vision
An emergency consultation with a vision specialist is required
when a sudden major change in vision is noticed.
To date, no drugs have been associated with the onset of diabetic retinopathy.
However, certain drugs promote dilation of blood vessels and
can accelerate the progression of diabetic retinopathy. Doctors know which
drugs to avoid and, when necessary, will recommend more
Diabetic retinopathy is a disease that can be prevented,
mainly through the management of diabetes.
There is no treatment for the nonproliferative form of diabetic retinopathy without
macular edema, but its progression can sometimes be
slowed by regular eye examinations and satisfactory management
of diabetes and other aggravating disorders, such as
high blood pressure. The proliferative form can be stopped.
Available treatments can often lead to an improvement in
Yes. Existing therapies have proven effective in slowing the
progression of symptoms of diabetic retinopathy. Even better, certain treatments
can actually improve vision.
A vitrectomy, a surgical operation in which the vitreous
humour is removed from the eye, can be performed in case
of massive or chronic vitreal hemorrhage, retinal detachment
and some cases of macular edema.
The signs and symptoms of diabetic retinopathy can appear in one eye only,
but usually both eyes are affected—though not necessarily
Monitoring by an optometrist or an ophthalmologist is indispensable
if you have diabetic retinopathy. The treatment required and the frequency
of visits will be determined by your vision specialist.
No, diabetic retinopathy is not painful. The eye examinations required and the
treatments available are not painful either.
Most people with diabetic retinopathy keep their driver’s licence. Corrected visual acuity must be at least 6/15 (20/50) to drive in Canada.
Yes. In the vast majority of cases, people with diabetic retinopathy can get
around on their own. Certain tools have been developed to
make it easier for people with a vision impairment associated
with advanced diabetic retinopathy to get around.
There are numerous vision aids (magnifiers, closed circuit televisions, etc.) that facilitate daily activities for people with advanced DR.
Yes. Vision often improves with treatment (laser photocoagulation,
antiangiogenic drugs or vitrectomy). However, diabetic retinopathy
sometimes results in permanent vision loss.
A very well-balanced diet and certain food guidelines are recommended
for people with diabetic retinopathy. Sugars and fats, which increase
blood sugar levels, must be avoided.
It’s always a good idea to quit smoking. Smokers are at greater
risk of cardiovascular disease, high blood pressure in particular—
a risk factor in diabetic retinopathy.
New treatments available in the last few years have considerably
improved the life of people with diabetic retinopathy by slowing the progression
of the disease and reducing symptoms. Research is
on-going, giving hope that future therapies will be even more
effective in minimizing complications and perhaps even, one
day, preventing the disease—or at least delaying its onset.