Why Diabetics Need Annual Eye Exams
Diabetes affects blood vessels throughout the body — including the tiny, delicate vessels of the retina. Over time, chronically elevated blood sugar damages these vessels, causing them to leak fluid, bleed, or grow abnormally. This condition, known as diabetic retinopathy, can progress silently for years without any noticeable change in vision.
This silent progression is precisely what makes annual screening so critical. Diabetic retinopathy is largely preventable and treatable when caught early — but once significant damage has occurred, some vision loss may be permanent. Early treatment reduces the risk of severe vision loss by more than 90%.
Canadian Diabetes Association clinical practice guidelines recommend a dilated retinal examination for all adults with diabetes. This is a different, more thorough examination than a routine optometry visit — it requires dilation of the pupils to allow a full view of the peripheral retina, and uses specialized imaging technology to detect subtle early changes.
What Is Diabetic Retinopathy?
Diabetic retinopathy is classified into two main stages, based on the presence or absence of abnormal new blood vessels:
Non-Proliferative Diabetic Retinopathy (NPDR)
In the early stages of diabetic retinopathy, the walls of the retinal blood vessels weaken. This causes microaneurysms — tiny balloon-like outpouchings that can leak blood and fluid. The retina may develop dot-and-blot hemorrhages, hard exudates (protein deposits from leaking vessels), and cotton-wool spots (areas of retinal ischemia).
- Mild NPDR: A few microaneurysms; vision is typically normal
- Moderate NPDR: More widespread microaneurysms, hemorrhages, and exudates; still usually asymptomatic
- Severe NPDR: Extensive hemorrhages in all four quadrants of the retina, venous beading, and intraretinal microvascular abnormalities (IRMA) — a high-risk stage with a substantial chance of progressing to proliferative disease
Proliferative Diabetic Retinopathy (PDR)
In response to areas of retinal ischemia, the eye releases growth factors (primarily VEGF) that stimulate the growth of abnormal new blood vessels on the retina and into the vitreous gel. These new vessels are fragile and prone to bleeding, causing vitreous hemorrhage (sudden blurring or loss of vision), and can cause tractional retinal detachment — a vision-threatening emergency. PDR is managed urgently with laser photocoagulation and/or anti-VEGF injections, and in advanced cases may require vitreoretinal surgery.
Diabetic Macular Edema (DME)
At any stage of retinopathy, fluid can leak into the macula — the small central area of the retina responsible for sharp, detailed vision used for reading, recognizing faces, and fine tasks. Macular edema is the most common cause of vision loss in people with diabetes. Patients may notice blurring or distortion of central vision. DME is now primarily treated with anti-VEGF injection therapy, which dramatically improves outcomes compared to laser alone.
Risk Factors for Diabetic Retinopathy
Not every person with diabetes develops significant retinopathy, but certain factors substantially increase risk:
- Duration of diabetes: The single most important risk factor. After 20 years of Type 1 diabetes, nearly all patients have some degree of retinopathy
- Poor glycemic control: Elevated HbA1c directly accelerates retinal vessel damage
- Hypertension: High blood pressure compounds the damage to retinal vessels
- Hyperlipidemia: Elevated lipids are associated with hard exudate formation and macular involvement
- Nephropathy: Kidney disease and retinopathy share the same microvascular damage mechanism and often coexist
- Pregnancy: Retinopathy can worsen significantly during pregnancy in women with pre-existing diabetes
- Anemia and sleep apnea: Both can worsen retinal ischemia
What the Exam Involves
A diabetic eye examination at Dr. Sundaram's clinic is a thorough medical assessment of the retina and optic nerve, not a routine vision test. The exam includes:
Pupil Dilation
Dilating drops are instilled to widen the pupils, allowing a complete view of the peripheral retina. Dilation typically lasts 3 to 4 hours; please arrange a driver if you are sensitive to bright light.
Dilated Fundus Examination
Dr. Sundaram directly examines the retina, optic disc, and macula using a slit lamp and condensing lens, assessing for microaneurysms, hemorrhages, exudates, neovascularization, and other retinal changes.
Optical Coherence Tomography (OCT)
OCT imaging provides a cross-sectional view of the retinal layers, sensitively detecting and quantifying macular edema — often before it is visible on clinical examination.
Fundus Photography
Wide-field retinal photographs create a permanent record of the retina's appearance, enabling objective comparison between visits to track progression or improvement over time.
After the examination, Dr. Sundaram will explain the findings, assign a retinopathy staging, and discuss any treatment recommendations. A detailed report is sent back to your referring physician or endocrinologist.
Treatment Options
Anti-VEGF Injections
Intravitreal anti-VEGF injections are the first-line treatment for diabetic macular edema and are also used for high-risk proliferative retinopathy. Injections are administered into the vitreous cavity in a sterile outpatient setting under topical anesthesia. Medications include ranibizumab (Lucentis), bevacizumab (Avastin), and aflibercept (Eylea). A loading series of monthly injections is typically followed by a maintenance schedule based on the treatment response.
Laser Photocoagulation
Focal or grid laser is used to seal leaking retinal vessels in cases of macular edema not responding to injections. Panretinal photocoagulation (PRP) is applied across the peripheral retina to reduce the stimulus for abnormal vessel growth in proliferative diabetic retinopathy — it is still an important tool for high-risk PDR.
Vitrectomy Surgery
For advanced complications such as non-clearing vitreous hemorrhage or tractional retinal detachment, vitreoretinal surgery removes the vitreous gel and addresses retinal damage. This is performed in a hospital operating room by a specialized vitreoretinal surgeon; Dr. Sundaram will coordinate appropriate referral if required.
How to Get Referred
Family physicians, general practitioners, endocrinologists, and internists caring for patients with diabetes are encouraged to refer for annual ophthalmology review. Please include:
- Diabetes type and duration
- Most recent HbA1c value
- Any history of retinopathy or prior eye treatment
- Current medications, including insulin and antihypertensives
Referrals can be sent to info@precisioneyesurgery.ca or by fax. Urgent referrals for sudden vision loss or suspected proliferative disease are accommodated promptly.
Diabetes & Eye Health in the Fraser Valley
The Fraser Valley has a notably high prevalence of Type 2 diabetes, reflecting the region's demographics. Research consistently shows that South Asian populations — a large and growing community in Abbotsford, Chilliwack, Surrey, and the surrounding area — have significantly higher rates of Type 2 diabetes compared to the general Canadian population, often presenting at younger ages and with greater insulin resistance. This population faces a disproportionate burden of diabetic retinopathy, yet is frequently underscreened.
Dr. Sundaram's practice is committed to serving this community with accessible, high-quality retinal care. Physicians and endocrinologists caring for South Asian patients with diabetes are strongly encouraged to refer for annual retinal evaluation, even in patients who report no visual symptoms.
Remember: Diabetic retinopathy has no symptoms in its early stages. By the time a patient notices blurring or vision loss, significant damage has often already occurred. Annual screening is the single most effective strategy for preventing blindness in people with diabetes.
Frequently Asked Questions — Diabetic Eye Exams
Most adults with Type 2 diabetes should have a comprehensive dilated retinal exam at diagnosis and annually thereafter. Adults with Type 1 diabetes should have their first exam within 5 years of diagnosis, then annually. Patients with established retinopathy may need follow-up every 3–6 months. Pregnant women with diabetes require close monitoring throughout pregnancy.
Yes — diabetic retinopathy is the leading cause of new blindness in working-age adults in Canada. However, when detected early and treated appropriately, the risk of severe vision loss can be reduced by over 90%. Most people with early retinopathy have no symptoms, which is why annual screening is so important: treatment is far more effective at early stages than after symptoms develop.
Diabetic macular edema (DME) occurs when leaking retinal vessels cause fluid to accumulate in the macula — the central area of the retina responsible for sharp, detailed vision. DME is the most common cause of vision loss in people with diabetes and causes blurred or distorted central vision. It is primarily treated with anti-VEGF injections, which reduce swelling and protect vision.
Anti-VEGF injections are administered directly into the eye's vitreous cavity in a sterile outpatient setting. The eye is numbed with anesthetic drops. The procedure takes only a few minutes. Patients typically need a series of monthly injections initially, followed by less frequent treatments as the condition stabilizes. Common medications include ranibizumab (Lucentis), bevacizumab (Avastin), and aflibercept (Eylea), some of which may be covered by PharmaCare or private drug plans.
Yes, significantly. Improving HbA1c substantially reduces the risk of developing retinopathy and slows its progression — this is supported by landmark trials including the DCCT and UKPDS. Blood pressure control and lipid management also protect the retina. Eye care is one component of a comprehensive diabetes management strategy that includes your GP, endocrinologist, and diabetes educator.
Your family physician, internist, or endocrinologist can refer you to Dr. Sundaram's office. Please bring your diabetes medications list, your most recent HbA1c result, and any previous retinal reports to your appointment. If you have not had a dilated retinal exam in over a year, please ask your GP for a referral today.