Your Complete Guide to Anti-VEGF Injection Treatment at Precision Retina Care
Document Version Control
Version: 1.0 | Created: July 2026 | Last Reviewed: July 2026 | Next Review Date: July 2027
What is Diabetic Macular Edema?
Understanding DME
The macula is the small central area of the retina at the back of your eye responsible for sharp, detailed vision.
Diabetic macular edema (DME) occurs when diabetes damages small blood vessels in the retina. These damaged vessels leak fluid into the macula, causing it to swell. This swelling blurs your central vision.
Why does this happen? High blood-sugar levels, or hyperglycemia, damage the blood vessels in your eye over time. When diabetes is not well controlled, these vessels become weak and leaky.
The impact
- Blurred or fuzzy central vision
- Difficulty reading, recognizing faces, or driving
- Colours appearing washed out or different
- Vision problems that may develop gradually or suddenly
Key Point About DME
DME is one of the most common causes of vision loss in working-age adults with diabetes. The good news is that effective treatment is available when started early.
Am I at Risk for DME?
Primary Risk Factors
Diabetes itself is the main risk factor. However, your risk increases if:
- You have had diabetes for many years
- Your blood sugar is poorly controlled
- You have high blood pressure
- You have high cholesterol
- You have diabetic kidney disease
- You smoke
- You are pregnant and have diabetes
Reducing Your Risk
The most important action you can take is to control your diabetes:
- Keep your blood-sugar levels as close to normal as possible
- Take diabetes medication exactly as prescribed
- Monitor your blood sugar regularly
- Maintain a healthy diet low in sugar and simple carbohydrates
- Exercise regularly, aiming for at least 150 minutes per week
- Maintain a healthy weight
- Control your blood pressure
- Stop smoking, if applicable
- Have regular eye exams at least once per year or more often if recommended
Why Early Detection Matters
Many people with DME do not realize they have it because vision loss can develop slowly. Regular eye exams are essential because:
- Early detection allows prompt treatment
- Starting treatment early helps prevent permanent vision loss
- Undetected DME can progress rapidly
- Vision damage from untreated DME may be permanent
Recognizing the Symptoms
Warning Signs You Should Know
Contact your eye doctor immediately if you notice:
- Blurred or fuzzy central vision that develops suddenly or gradually
- Difficulty reading or seeing fine details, even with glasses
- Trouble recognizing faces
- Dark spots or shadows in the centre of your vision
- Distorted vision, with straight lines appearing wavy or bent
- Colours appearing different or less vivid than usual
- Floaters, which are small spots or lines floating in your vision
- Sudden vision changes in one or both eyes
- Difficulty with everyday activities such as cooking, managing finances, or using a computer
When to Seek Urgent Care
If you experience a sudden, significant change in your vision, do not wait for a routine appointment. Contact your eye doctor the same day or seek emergency eye care. Rapid vision loss in DME requires prompt evaluation.
How is DME Diagnosed?
Comprehensive Eye Examination
Your ophthalmologist will perform several tests to diagnose DME.
Visual Acuity Test
Your doctor will check how clearly you can see with an eye chart.
Dilated Eye Examination
Your pupils will be dilated or widened using special drops. This allows your doctor to examine the entire retina and look for swelling or leakage.
Diagnostic Testing
Diagnostic testing is individualized and may include:
- Optical coherence tomography (OCT): Creates detailed cross-section images of the retina to measure swelling and fluid
- Retinal photography: Produces detailed photos of the retina
- OCT angiography: Shows blood-vessel circulation patterns
- Fluorescein angiography: Uses dye injected into your arm to highlight leaking blood vessels
- Other imaging when clinically indicated
Blood-Sugar and Blood-Pressure Monitoring
Your doctor will discuss your blood-sugar control and may recommend monitoring your diabetes management. Good diabetes control is critical for successful DME treatment.
Treatment Options for DME
Anti-VEGF Injections
VEGF stands for “vascular endothelial growth factor”—a protein that tells the body to grow new blood vessels.
The problem: In DME, damaged blood vessels produce too much VEGF, which causes additional vessel damage and leakage. This leads to fluid accumulating in the macula.
The solution: Anti-VEGF medications are injected directly into the eye. They block this protein, preventing additional vessel damage and stopping fluid leakage.
The result
- Fluid gradually decreases in the macula
- Swelling decreases
- Vision stabilizes
- Vision improves in many patients
- The progression of DME is slowed or halted
Your ophthalmologist will recommend a medication appropriate for your condition and discuss the evidence, benefits, risks, and approval status of the recommended medication.
Treatment recommendations are based on your ophthalmologist’s clinical assessment, current evidence, and your individual circumstances.
Timeline: What to Expect
Phase 1: Initial Evaluation Before Treatment Starts
Precision Retina Care provides specialized assessment and treatment clinics for patients with wet age-related macular degeneration, diabetic macular edema, and retinal vein occlusion. Our structured approach includes comprehensive assessment and diagnostic testing to confirm the diagnosis and develop a personalized treatment plan.
First appointment
- Comprehensive eye examination
- Individualized diagnostic testing that may include OCT, retinal photography, OCT angiography, fluorescein angiography, and other imaging when clinically indicated
- Review of your medical history, including diabetes control
- Discussion of treatment options
- Answers to your questions and concerns
What we are determining
- Is it definitely DME?
- What is the extent of the swelling?
- Is an anti-VEGF injection the right treatment for you?
- Which treatment option is most appropriate?
- Are there any contraindications?
- How well is your diabetes currently controlled?
What you should do
- Write down questions beforehand
- Bring a list of current medications, including diabetes medication
- Bring blood-sugar logs if you keep them
- Ask about costs and insurance coverage
- Discuss concerns about the procedure
- Arrange transportation if needed
Phase 2: Intensive Treatment During Months 1–3
Initial Schedule: Monthly Injections
Most patients receive injections in Month 1, Month 2, and Month 3.
What Happens at Each Injection Appointment
Duration: Up to one hour in total, including preparation and monitoring.
- Registration and paperwork: five to 10 minutes
- Arrive 10–15 minutes early
- Check in and confirm your information
- Pre-injection testing: approximately 20 minutes
- Visual-acuity check
- Intraocular-pressure measurement
- OCT imaging to assess fluid levels
- These tests are painless and quick
- Dilating the eyes for a complete examination: approximately 30 minutes
- Dilating drops are placed in your eyes
- The drops allow a complete retinal examination
- Your doctor evaluates the back of the eye
- The macula and surrounding structures are assessed in detail
- Numbing and preparation: approximately five minutes
- Anaesthetic eye drops are placed in the eye
- Your eye will feel numb and tingly
- The injection area is prepared using sterile techniques
- A protective drape is placed
- The injection: less than 30 seconds
- You will see a bright light from the speculum holding your eye open
- You may feel pressure, but the eye is numb
- The actual injection is very brief
- Some patients report seeing a flash or feeling slight pressure
- Post-injection care: approximately five minutes
- Your ophthalmologist will provide appropriate post-procedure medications or instructions
- Your eye may feel slightly scratchy, which is normal
- You will rest briefly
- You will receive home-care instructions
- Discharge: approximately five minutes
- You will be cleared to go home
- Most patients can resume their usual activities shortly afterward
- Your ophthalmologist may recommend temporary restrictions
- Mild grittiness in the eye is normal for a few hours
After Your Injection
Important: Everyone experiences the injection process differently. If you experience anything unexpected, contact your doctor’s office. Precision Retina Care provides written instructions and emergency contact information so you know how to reach the team if you have concerns.
Possible sensations after the injection
- Some grittiness or mild discomfort in the eye
- Floaters or small shadows, which should be reported if they persist or worsen
- Slight redness that may last for hours or days
- Mild sensitivity to light
If something concerns you
- Contact your doctor’s office
- Do not wait to see whether symptoms resolve on their own
- The care team is available to help and answer questions
- Use the emergency contact information in your written instructions
Physical Sensations During the Injection
Everyone experiences the injection differently. Although your eye is numbed with anaesthetic drops, you may feel some discomfort during the procedure. Most patients tolerate the injection well.
What you might feel
- Pressure in the eye
- Awareness of the syringe approaching because you will see the light
- Brief discomfort or mild, tolerable pain as the medication enters
- Brief dimming of vision
- Sensitivity to the speculum holding the eye open
What to know
- Numbing drops are used to minimize discomfort
- The procedure is very brief
- Any discomfort is temporary
- Patients generally tolerate the procedure well
Phase 3: Maintenance and Monitoring During Month 4 and Beyond
After the first three injections, your treatment plan will be adjusted based on your response.
Common Maintenance Schedules
Every four weeks
- Used if the eye continues to have fluid
Every six weeks
- Some eyes respond well with less frequent injections
Every eight weeks
- Some medications can be extended to this interval if vision is stable
Every 12 weeks
- Some patients with well-controlled DME may achieve this interval
Individualized approach
- Your schedule is based on your specific response
- Your doctor closely monitors your progress
- The schedule may change as your condition evolves
- Controlling diabetes helps optimize your response to treatment
The Importance of Diabetes Control
Why Blood Sugar Matters
Keeping your blood sugar well controlled during DME treatment is critical because:
- Better diabetes control improves the response to treatment
- High blood sugar can cause new leakage even while treatment is underway
- Stable blood sugar helps prevent progression in the other eye
- Good control protects against other diabetes-related eye complications
Before Each Appointment
Bring:
- Blood-sugar logs if you monitor at home
- A list of current diabetes medications
- Questions about diabetes management
- Information about recent blood-sugar readings
Discussing Diabetes Control With the Team
Tell your ophthalmologist if:
- Your blood sugar has been difficult to control
- You have changed your diabetes medications
- You are experiencing low blood-sugar episodes, or hypoglycemia
- You are having difficulty taking medication as prescribed
Your eye-care team and primary-care doctor work together to help manage both your diabetes and eye health.
What to Bring to Appointments
Every visit
- OHIP card
- Photo ID
- List of current medications, including diabetes medication
- Blood-sugar logs, if applicable
- Written questions or concerns
- Amsler-grid results if you are self-monitoring
- Notepad to record instructions
- Consider arranging transportation, particularly for your first treatment
First visit
- Medical history, especially the date of your diabetes diagnosis and current control
- List of current medications and supplements
- Information about previous eye surgery or injury
- Family history of eye disease and diabetes
- Recent blood-sugar readings or A1C results, if available
Key Questions to Ask Your Doctor
Before starting treatment
- Why is this medication recommended for me?
- What are the side effects?
- How will we know whether treatment is working?
- What is the expected injection schedule?
- What happens if I need to skip an injection?
- Are there activities I should avoid?
- How does blood-sugar control affect treatment?
During treatment
- How am I responding to the medication?
- Do we need to adjust the schedule?
- What should I monitor between visits?
- When can I expect improvement?
- What are realistic goals for my vision?
- Are other treatments available?
Long term
- How long will I need injections?
- Can I ever stop treatment?
- What happens if I stop receiving injections?
- What is the prognosis for my vision?
- What can I do to prevent DME in my other eye?
- How does diabetes control affect treatment?
Tips for a Smooth Treatment Experience
Before Each Appointment
- Arrange transportation: Consider arranging transportation, particularly for your first treatment or if your pupils will be dilated.
- Eat a light breakfast or lunch.
- Take regular medication as scheduled, including diabetes medication.
- Wear comfortable clothing.
- Remove jewellery or accessories that might interfere with the procedure.
- Remove your contact lens from the eye being treated, if applicable.
- Check your blood sugar before coming if you monitor at home.
At the Office
- Arrive 10–15 minutes early.
- Take deep breaths to remain relaxed.
- Ask questions about the procedure.
- Tell the staff if you are anxious.
- Follow all instructions carefully.
- Ask for clarification if you do not understand something.
Managing Anxiety
Many patients are anxious before their first injection. This is completely normal.
Things that help
- Understanding what to expect
- Having someone with you for support
- Deep-breathing exercises
- Asking staff questions before the procedure
- Remembering that numbing drops are used
- Focusing on the goal of preserving your vision
Talk to your doctor if
- Your anxiety is overwhelming
- You need additional time or support
- You want to discuss options that may make the procedure easier
Potential Side Effects and What to Watch For
Although mild scratchiness and discomfort for a few hours after an injection can be normal, contact your doctor immediately if you notice any of the following.
Rare but Serious: Call Immediately
- Severe eye pain
- Significant decrease in vision
- Persistent floaters that worsen
- Signs of infection, including increasing redness, pus, or warmth
- Bleeding or new spots in your vision that do not improve
Serious Complications: Very Rare
Serious complications from anti-VEGF injections are extremely rare. When they occur, they may include:
- Retinal detachment
- Endophthalmitis, or an eye infection
- Cataract progression
Important: Your doctor will review warning signs with you and provide written instructions explaining how to contact the office or seek urgent help. Keep this information accessible and do not hesitate to reach out with concerns.
Realistic Expectations
What Anti-VEGF Can Do
- Stop vision loss in most patients
- Reduce macular swelling or edema
- Stabilize vision so that it does not worsen
- Improve vision in many patients
- Slow disease progression
- Reduce the risk of vision loss from DME
What Anti-VEGF Cannot Do
- Cure DME, which is a chronic condition requiring ongoing management
- Restore vision that was already lost before treatment began
- Replace the need for diabetes control
- Work immediately; improvement takes weeks to months
- Prevent other diabetes-related eye problems, although good control helps
Timeline for Results
- After the first injection: You may see minimal change.
- After the second injection: Some improvement in swelling may be visible.
- After the third injection: The maximum effect is usually seen.
- Ongoing: Stability is maintained with continued treatment and good diabetes control.
Some patients respond faster and others more slowly. The response is individual and depends on factors such as blood-sugar control.
Managing Treatment Long Term
Staying Committed to Treatment
Once anti-VEGF treatment begins, staying consistent is crucial because:
- Disease progression can resume quickly if treatment stops
- Fluid can return within days or weeks
- Uncontrolled diabetes makes treatment less effective
- Vision loss from missed appointments may be permanent
- Regular monitoring helps optimize treatment
Managing Your Diabetes During Treatment
Diabetes control is critical for treatment success:
- Work closely with your primary-care doctor
- Take diabetes medication exactly as prescribed
- Monitor your blood sugar regularly
- Keep your A1C as close to its target as possible
- Maintain a healthy diet
- Exercise regularly
- Attend appointments with both your eye doctor and diabetes-care team
Making Treatment Work With Your Schedule
If appointments are difficult
- Talk to your doctor about your challenges
- Ask about early-morning or late-afternoon appointments
- Ask whether a staff member can help address barriers
- Ask about transportation resources
If you are struggling financially
- Financial-assistance programs may be available for eligible patients, depending on the medication prescribed
- Discuss cost concerns with your doctor
- Ask about available options
- Patient advocates may be able to help
If you are struggling emotionally
- It is normal to feel overwhelmed about both diabetes and eye disease
- Ask about support groups or counselling
- Talk to your doctor about your concerns
- Connect with other people living with diabetes and DME
When to Adjust or Change Treatment
Your doctor may recommend treatment changes if:
- You are not responding well: The eye continues to have fluid despite treatment
- You experience side effects: Significant adverse effects develop
- A different medication is needed: Another anti-VEGF medication may work better
- The interval can be adjusted: The eye is responding and injections can be spaced farther apart
- The dosage should be adjusted: A different dose may be more suitable
- Diabetes-control problems interfere with treatment: Poor blood-sugar control may limit treatment success
Never stop or change treatment on your own. Always discuss changes with your doctor.
Clinical Trials at Precision Retina Care
Precision Retina Care is involved in clinical trials in AMD, diabetic macular edema, and retinal vein occlusion.
If you are eligible for a study
- You will be informed about potential research studies and opportunities
- Study information will be discussed with you
- You can ask questions about participation
- Participation is offered only when appropriate and after a separate informed-consent discussion
Important
- Participation is completely voluntary and independent of clinical care
- Choosing not to participate will not affect your treatment or care at Precision Retina Care
- Your clinical care remains the primary focus
Frequently Asked Questions
About the Injection
Does it hurt?
Everyone experiences the injection differently. The eye is numbed with drops, but you may feel some discomfort. Most patients tolerate the injection well, and any discomfort is brief.
Can I see the needle going in?
You will see a bright light and be aware of the syringe approaching, but the procedure is very quick.
Is there any bleeding?
Occasionally, minor bleeding develops under the conjunctiva, the clear membrane covering the white of the eye. This is harmless and resolves on its own.
About the Process
How long does the whole appointment take?
The appointment usually takes up to one hour, including check-in, testing, the injection, and monitoring.
Can someone come with me?
Yes. Having someone with you can provide support, particularly during your first appointment. This is especially recommended if your pupils will be dilated or you would prefer someone to be present.
Do I need to take time off work?
Most people do not. The procedure is quick, and you can usually resume normal activities immediately.
Can I drive home after the injection?
Your ability to drive depends on whether your pupils were dilated and your individual circumstances. Discuss this with your ophthalmologist before your appointment. If your pupils are dilated, your vision may be temporarily affected and you should consider arranging transportation.
About Results
When will I see improvement?
This varies. Some patients see improvement within weeks, whereas others require several months. Stabilization of vision and reduction in swelling are common outcomes.
What if I do not see improvement?
Talk to your doctor. Your medication, dosage, or treatment frequency may be adjusted. Sometimes a different anti-VEGF medication works better. Diabetes control also affects the response.
How long will I need treatment?
DME is a chronic condition. Most patients need ongoing treatment indefinitely, although the frequency may decrease as the condition stabilizes.
Can my blood-sugar levels affect treatment?
Yes, significantly. Poor blood-sugar control can limit the effectiveness of treatment and increase the risk of new vision problems. Good diabetes control is essential for the best outcomes.
About Safety
Is the medication safe?
Your ophthalmologist will recommend a medication appropriate for your condition and discuss its evidence, benefits, risks, and approval status.
What about my other eye?
Both eyes should be monitored regularly. If you have diabetes, your other eye is at risk of developing DME. Regular check-ups can identify problems early.
Can I have an allergic reaction to the medication?
True allergies are very rare. Report unusual symptoms to your doctor.
Will treatment prevent DME in my other eye?
Treatment in one eye does not prevent DME in the other. However, good blood-sugar control and regular eye exams help identify problems early. Tell your doctor if you notice changes in the other eye.
Your Role in Success
Successful treatment depends on a partnership between you and your medical team.
What your doctor does
- Carefully monitors your response
- Adjusts treatment as needed
- Provides skilled injections
- Communicates with your referring doctor and primary-care team
What you do
- Keep all appointments
- Self-monitor using the Amsler grid
- Report vision changes promptly
- Take medication as prescribed
- Maintain good diabetes control
- Ask questions and communicate concerns
- Stay engaged in your care
- Work with your diabetes-care team
Living Well With DME and Treatment
Daily Life
- Continue regular activities as tolerated
- Exercise and stay active to support diabetes control and eye health
- Maintain a healthy diet appropriate for diabetes management
- Wear UV-protective sunglasses
- Monitor your blood sugar as directed
- Do not smoke
- Monitor your vision daily using the Amsler grid
Maintaining Independence
Many people maintain independence and quality of life while receiving anti-VEGF treatment for DME, including:
- Driving when appropriate
- Reading and participating in hobbies, with adaptations as needed
- Working and socializing
- Travelling
- Staying engaged in life
Managing Multiple Conditions
Living with both diabetes and DME can feel overwhelming:
- You are managing more than your eyes
- Good diabetes control benefits your entire body
- Eye treatment is part of comprehensive diabetes care
- Many people successfully manage both conditions
Emotional Support
It is normal to have mixed feelings about a DME diagnosis and treatment, including:
- Fear about vision loss and blindness
- Frustration with managing a chronic disease
- Worry about treatment effectiveness
- Concern about diabetes management
These feelings are valid. Consider:
- Connecting with other people who have diabetes and DME
- Talking to a counsellor or therapist
- Joining a diabetes support group
- Discussing concerns with your healthcare team
- Learning more about diabetes management
When to Reach Out to Your Doctor
Contact your doctor before your next scheduled appointment if:
- Your vision changes significantly
- You develop new symptoms
- You notice new floaters or shadows
- You have concerns about treatment
- You are struggling with the appointment schedule
- You have questions about your condition
- You want to discuss alternative treatments
- Your blood sugar has been difficult to control
- You have changed your diabetes medication
Resources
At Precision Retina Care
- Your care team is available to support you
- Ask for educational materials
- Request referrals to support services
- Discuss concerns openly
Diabetes Resources
- Diabetes Canada
- Local diabetes-education programs
- Your primary-care doctor or endocrinologist
Eye-Health Resources
- American Academy of Ophthalmology
- National Eye Institute
- Patient support organizations
- Low-vision rehabilitation services
Summary: Your Treatment Journey
- Evaluation: Comprehensive assessment and treatment planning
- Initial phase: Three monthly injections during Months 1–3
- Monitoring: Regular visits to assess your response
- Maintenance: Ongoing injections on an individualized schedule
- Long term: Continued treatment to preserve vision and manage diabetes
The goal is to preserve your vision and maintain your quality of life through consistent, evidence-based treatment combined with good diabetes control.
Final Thoughts
Diabetic macular edema is a serious eye condition, but modern treatment works. Combined with good diabetes management, regular injections and monitoring can help many patients:
- Stop their vision loss
- Reduce macular swelling
- Stabilize or improve their vision
- Maintain independence and quality of life
You are not alone in this journey. Your eye-care team, diabetes-care team, family, friends, and other people living with diabetes and DME are here to support you.
Addendum
Clinical Care Provider
Clinical care is provided by Dr. Varun Chaudhary and the Precision Retina Care team at the Hamilton Regional Eye Institute.
Medical Review and Approval
This patient-education guide has been reviewed and approved by Dr. Varun Chaudhary, MD, FRCSC, an ophthalmology specialist with expertise in retinal disease.
Accessibility
This guide is available in large print, audio format, and alternative formats upon request. Please call the office to request an alternative format.
Educational Use
This guide is intended for patient education and does not replace individualized medical advice from your ophthalmologist. Always follow the recommendations provided by your treating eye specialist.
Precision Retina Care | Retina Consultants of Hamilton