Diabetic Retinopathy

The risk of blindness is 25 times higher for someone with diabetes, making it the leading cause of blindness in Canada. Diabetic retinopathy affects individuals diagnosed with type 1 or 2 diabetes. Uncontrolled high blood sugar levels cause damage to retinal blood vessels.


Careful diabetes management is the best vision loss preventative. Diabetics should see their eye doctor for yearly eye examination, even if you remain without symptoms as early detection is necessary for modern treatment options to prove effective. If required, Dr. Conlon will refer you to a retinal specialist.

Diabetic Retinopathy FAQ

Q: What is diabetic retinopathy?

A: Diabetic retinopathy is a diabetes complication characterized by damage to retinal blood vessels. The retina is the light-sensitive tissue lining the back of the eye. Chronically high blood sugar, symptomatic of diabetes, blocks the blood flow to the retina, and can cause fluid leaks or hemorrhages. This damage leads to vision impairment and eventual blindness.

Q: What causes diabetic retinopathy?

A: The retina’s blood vessels are small, matching the delicate nature of the tissue, making these vessels particularly susceptible to damage from high blood sugar levels. The condition progresses through four stages as the retina faces increasing damage:

  1. Mild nonproliferative retinopathy. The retina’s blood vessels swell, which may cause fluid leakage in the retina.
  2. Moderate nonproliferative retinopathy. Blood vessels swell and distort, causing them to become incapable of transporting blood.
  3. Severe nonproliferative retinopathy. Many blood vessels are blocked, depriving blood supply to areas of the retina. In response, these areas secrete growth factors, signalling to the retina to grow new blood vessels.
  4. Proliferative diabetic retinopathy (PDR). In this stage, new blood vessels are created but they are fragile, leading to increased leakage and bleeding. This continued damage creates scar tissues, which contracts causing retinal detachment, meaning the retina pulls away from the underlying tissue. As the retina sends visual images to the brain via the optic nerve, this detachment can cause permanent vision loss.

Q: Who is at-risk for diabetic retinopathy?

A: Diabetics of every type are susceptible to diabetic retinopathy. Duration of the illness can increase the risk of developing the condition. Diabetic women are susceptible to rapid onset or worsening of the condition when pregnant. Other factors include—control of blood sugar levels, high blood pressure, high cholesterol, tobacco use, and ethnic background.

Q: Can diabetic retinopathy be prevented?

A: The duration of diabetes increases the likelihood of developing diabetic retinopathy. Thus it is important for diabetics to control their blood sugar levels. Lifestyle changes may minimize developing diabetic retinopathy: implementing frequent monitoring and recording of blood sugar levels, a healthy diet and exercise routine, refraining from smoking or use of other tobacco products, and controlling blood pressure are all good measures.

Although health monitoring is important, ultimately these lifestyle changes may still prove ineffective, as diabetic retinopathy is the most common cause of vision loss in diabetics. Therefore, it is imperative to receive yearly comprehensive eye exams if at-risk for the condition.

Q: How is diabetic retinopathy detected?

A: Symptoms typically do not appear until vision damage has already occurred, meaning close monitoring and medical testing are necessary for early detection of diabetic retinopathy.

Hemoglobin A1C(HbA1c). Ordered by your family physicianthis test provides a three-month average of blood sugar levels. This average indicates how well blood sugar is controlled, with the usual goal of having an HbA1c at or below seven percent. Experts recommend this testing at least two times a year, but depending on your blood sugar management, more frequent testing may be needed. This test indicates whether your blood sugar may be harming your eyes.

Dilated Eye Exams. Dr. Conlon performs these exams, to examine the back of the eye. He will administer drops to dilate your pupils, as enlarging them allows for a better view of the back of your eye. Using a magnifying lens, Dr. Conlon can diagnose any eye damage.

If necessary, Dr. Conlon can also refer patients to a retinal specialist for more extensive testing, including Fluorescein Angiography, which identifies specific leakages.

Q: What symptoms are caused by diabetic retinopathy?

A: The early stages of diabetic retinopathy typically progress unnoticed by sufferers. The condition is usually recognized only once symptoms start causing vision loss: blurred vision, vision fluctuations, colour perception difficulties, and floaters, flashes of light, or dark spots in the visual field. Advanced cases can lead to macular edema (swelling in part of the retina), and retinal detachment. The condition also raises the risk of glaucoma and cataracts.

Q: Does diabetic retinopathy cause blindness?

A: In its later stages, diabetic retinopathy can result in irreversible vision loss. Preventative measures and medical observation are key in eliminating this possibility.

Q: How is diabetic retinopathy treated?

A: Treatment options are dependent on the severity of the condition.

Anti-VEGF Injection Therapy involves injection in the eye’s gel to block a protein that stimulates the growth of abnormal blood vessel. It has proven effective for slowing progression of diabetic retinopathy.

Scatter laser surgery is the traditional treatment, making thousands of laser burns into retinal areas besides the macula. These burns shrink abnormal blood vessels and are usually most effective before new blood vessels begin bleeding.

Vitrectomy, a surgical procedure that removes the vitreous humor gel filling the eye cavity, is another treatment option.

Q: Can treatment restore vision?

A: Treatment is usually intended to prevent further vision loss, although depending on complications, improvements to vision can occur.