What you should know about: Diabetic Eye Disease

Diabetic eye disease refers to a group of eye problems that can affect people with diabetes. These conditions include diabetic retinopathy and diabetic macular edema (DME). Diabetes can also increase your risk of developing cataracts and glaucoma. Diabetes can cause damage to the blood vessels in the retina, the light-sensitive tissue at the back of the eye, leading to vision impairment or blindness if not treated in time. 

Diabetic retinopathy occurs when high blood sugar levels damage the blood vessels in the retina. This can cause the vessels to leak fluid or bleed, leading to swelling, scarring or even detachment of the retina. Diabetic macular edema (DME), a complication of retinopathy, is characterized by swelling in the macula—the part of the retina responsible for sharp, central vision. 

People with diabetes are also at higher risk of developing cataracts and glaucoma. Cataracts occur when the lens of the eye becomes cloudy, while glaucoma results from chronic progressive damage to the optic nerve, the cable that connects your eye to your brain, often due to increased eye pressure. 

The primary cause of diabetic eye disease is prolonged high blood sugar levels, which can damage the blood vessels in the retina and other parts of the eye by decreasing their elasticity, causing them to narrow and impeding flow. Other factors, such as high blood pressure and high cholesterol, can worsen this damage as the heart will compensate for the narrow arteries by increasing blood pressure. 

Individuals with diabetes—both type 1 and type 2—are at risk for diabetic eye disease. The longer someone has diabetes, the greater their risk of developing eye-related complications. Poor blood sugar control, smoking, and kidney disease can also increase the likelihood of diabetic retinopathy. 

In the early stages, diabetic eye disease may not present noticeable symptoms. This is why it is essential for people with diabetes to have regular eye exams. As the disease progresses, symptoms may include: 

• Blurred, wavy or fluctuating vision 

• Dark or empty areas in your vision 

• Difficulty seeing at night 

• Colors appearing faded or washed out 

• Sudden vision loss 

In the case of diabetic macular edema (DME), vision loss can be rapid if the swelling in the macula is left untreated. 

If you experience any of these symptoms, especially a sudden change in vision, it’s important to contact your optometrist or ophthalmologist right away for an evaluation. 

If you don’t have an optometrist or ophthalmologist, or they’re not available, and you’re in or near Waterloo, call the Waterloo Eye Institute’s ocular disease service at 519-888-4623. You don’t need to be an existing patient. An on-call optometrist is available for certain hours outside regular clinic times – for more information, see Urgent and After-Hours Care. If acute symptoms start outside on-call hours, go to the nearest emergency room. 

Diagnosing diabetic eye disease involves a comprehensive eye exam, which may include: 

• Dilated eye exam: Your eye care professional will put drops in your eyes to dilate (widen) the pupils. This allows them to see the back of your eyes, where the retina is located, and look for signs of damage. 

• Optical coherence tomography (OCT): A non-invasive imaging test that provides detailed pictures of the retina, allowing your optometrist to detect swelling, fluid leakage, and other changes. 

The good news is that early detection and treatment can prevent or delay vision loss in most people with diabetic eye disease. 

• Blood sugar management: Keeping your blood sugar, blood pressure and cholesterol under control is the first line of defense in preventing or slowing the progression of diabetic eye disease. Regular follow-ups with your family doctor and at-home monitoring are recommended.  

• Laser treatment: In some cases, laser surgery is used to stop or slow down leaking blood vessels in the retina. This can help prevent further vision loss, especially in the case of diabetic retinopathy and macular edema. 

• Anti-VEGF injections: Medications known as anti-VEGF drugs are injected into the eye to reduce swelling in the macula. These injections are used to treat diabetic macular edema and are often given over several months. 

• Surgery: In advanced cases of diabetic retinopathy, surgery may be necessary to remove blood from the eye and repair retinal detachments. 

If you have cataracts or glaucoma induced by diabetes, cataract surgery or glaucoma treatments may also be recommended. 

At the Waterloo Eye Institute, we recommend that people with diabetes have a comprehensive eye exam at least once a year. We provide a range of treatments and advice for diabetic patients, including specialized assessments and management of early-stage diabetic retinopathy. However, if more advanced conditions are detected—such as diabetic macular edema or proliferative diabetic retinopathy—patients may be referred to an ophthalmologist for further care. 

Coverage and Costs: 

• OHIP Coverage: 

Diabetic patients of any age are covered by OHIP for one comprehensive eye exam per year. This coverage includes up to two follow-up visits. OHIP also covers annual eye exams and two follow-ups for people 19 and under or 65 and older. For patients aged 20 to 64, OHIP does not cover routine eye exams unless they have specific medical conditions that require eye care. Patients should consult with their healthcare provider regarding eligibility. 

• Out-of-Pocket Costs: 

Certain advanced tests may require an additional fee. For example, Optical Coherence Tomography (OCT), which provides detailed imaging of retinal layers to detect subtle changes, is not covered by OHIP and incurs an extra charge. 

Participation in research studies is an invaluable way to contribute to advancements in eye and vision care, potentially leading to new or improved treatments. By volunteering, you can play a role in furthering our understanding of eye health and helping shape future treatment options.  Learn more about volunteering in our research.