Anti-VEGF intravitreal injections

Introduction

If you or a family member has been told that an anti-VEGF injection into the eye is needed, you are not alone. These injections have become one of the most widely used treatments in eye care over the last two decades, and they have changed the outlook for people with several serious retinal conditions that once led to severe and permanent vision loss.

Anti-VEGF treatment is given as a small injection directly into the jelly-like substance inside the eye, called the vitreous. The procedure is quick, done in a clinic or day-care setting, and uses numbing drops so that it is generally well tolerated. What often surprises people is not the injection itself but the fact that it usually needs to be repeated — sometimes for many months, sometimes for years — to keep the eye stable.

This guide is written for people who already have a diagnosis such as wet age-related macular degeneration (AMD), diabetic macular edema, diabetic retinopathy, retinal vein occlusion, or another condition where these injections are used. It explains what anti-VEGF therapy is, what to expect at each visit, the main drug options, possible risks, and what life looks like during a long course of treatment.

What Are Anti-VEGF Intravitreal Injections?

The term “anti-VEGF” stands for “anti-vascular endothelial growth factor.” VEGF is a natural protein in the body that signals blood vessels to grow and to leak fluid. In a healthy eye, VEGF levels are low and well controlled. In several retinal diseases, the eye produces too much VEGF. This causes new, fragile blood vessels to grow in the wrong places and existing vessels to leak fluid and blood into the retina — the light-sensing layer at the back of the eye that is essential for vision.

Anti-VEGF medicines are antibody-based drugs that bind to VEGF and block its action. When injected into the vitreous, they reach the retina at a much higher concentration than would be possible with tablets or eye drops. The drug works locally to:

• Reduce leakage of fluid into the retina
• Shrink abnormal blood vessels that have already grown
• Slow or prevent the growth of new abnormal vessels

The word “intravitreal” simply means “into the vitreous.” The injection is given through the white of the eye (the sclera) using a very fine needle. Although the idea of an injection into the eye can sound alarming, the procedure has been performed millions of times worldwide and is one of the most studied treatments in modern ophthalmology.

Why Anti-VEGF Injections Are Performed

Anti-VEGF injections are used to treat conditions in which abnormal blood vessels or leaking blood vessels at the back of the eye are damaging vision. The most common reasons doctors recommend them include the following.

Wet (Neovascular) Age-Related Macular Degeneration

In wet AMD, abnormal blood vessels grow beneath the macula — the central part of the retina responsible for sharp, detailed vision. These vessels leak fluid and blood, distorting and damaging central vision. Before anti-VEGF therapy became available, wet AMD often led rapidly to severe central vision loss. Anti-VEGF treatment is now considered the first-line therapy for wet AMD by the American Academy of Ophthalmology and other major ophthalmology societies, and has been shown in large clinical studies to stabilise vision in most patients and to improve vision in a substantial proportion.

Diabetic Macular Edema (DME)

In people with diabetes, prolonged high blood sugar damages the small blood vessels of the retina. These vessels can leak fluid into the macula, causing swelling (edema) and blurred central vision. Anti-VEGF injections reduce this swelling and have largely replaced laser as the first-line treatment for vision-threatening DME involving the centre of the macula, according to current retinal society guidance.

Diabetic Retinopathy

In more advanced diabetic retinopathy, abnormal new vessels can grow on the surface of the retina or the optic nerve. These vessels bleed easily and can pull on the retina, causing retinal detachment. Anti-VEGF injections can help shrink these vessels and reduce the risk of bleeding, either on their own or in combination with laser treatment.

Retinal Vein Occlusion (RVO)

When a vein draining the retina becomes blocked, pressure builds up, and fluid leaks into the macula. This is called macular edema due to retinal vein occlusion. Anti-VEGF injections are widely used to reduce the swelling and improve vision in both branch and central retinal vein occlusion.

Myopic Choroidal Neovascularisation

People with severe near-sightedness (high myopia) sometimes develop abnormal vessels under the macula. Anti-VEGF injections are the standard treatment for this condition.

Other Less Common Indications

Anti-VEGF injections are also used for selected cases of:

• Neovascular glaucoma, where abnormal vessels grow on the iris
• Some inflammatory or hereditary causes of abnormal vessel growth
• Retinopathy of prematurity in babies (covered in a dedicated section below)

Anti-VEGF Drug Options

Several anti-VEGF medicines are in clinical use. They share the same general goal of blocking VEGF but differ in molecular structure, how long they last in the eye, and the specific approvals they hold.

Ranibizumab

Ranibizumab was one of the first anti-VEGF drugs developed specifically for use in the eye. It has been approved and used for wet AMD, DME, RVO-related edema, and other indications for many years, and has an extensive safety and efficacy record.

Aflibercept

Aflibercept is designed to bind VEGF tightly and tends to last longer in the eye than earlier agents. It is approved for the same major indications and is widely used. A higher-dose form of aflibercept has also become available in some settings, with the goal of allowing longer intervals between injections.

Bevacizumab

Bevacizumab was originally developed as a cancer treatment but was found to work well when used in much smaller doses inside the eye. It is used “off-label” for retinal disease in many countries, including India. Large head-to-head clinical trials have shown that bevacizumab produces vision outcomes broadly comparable to ranibizumab in conditions such as wet AMD and DME, which is why it remains in widespread use globally.

Brolucizumab

Brolucizumab is a smaller molecule that can be given at higher concentrations and may allow longer intervals between injections in some patients. Its use is shaped by safety considerations around a specific type of inflammation that has been reported with this drug, which your retina specialist will discuss with you.

Faricimab

Faricimab is a newer agent that blocks both VEGF and another molecule called angiopoietin-2, which is also involved in abnormal vessel growth and leakage. It is being used in wet AMD and DME, often with the goal of extending the interval between injections.

Which drug a retina specialist chooses depends on the diagnosis, response to previous treatments, the patient’s other eye and general health, and current availability. It is common to start with one agent and switch to another if the response is incomplete.

Who Is a Candidate for Anti-VEGF Injections?

Anti-VEGF injections are considered when a retinal condition involves abnormal new vessels, leaking vessels, or significant fluid build-up that is damaging vision. The decision to treat usually rests on a combination of:

• The diagnosis confirmed on retinal examination
• Imaging tests, especially optical coherence tomography (OCT), which provides a cross-sectional picture of the retina and shows fluid and swelling in detail
• Sometimes fluorescein angiography or OCT angiography, which show blood vessel patterns and leakage
• The level of vision and how it is affecting daily life

Some people may not be suitable candidates, or may need extra precautions, including those with:

• An active infection in or around the eye, which usually needs to be treated first
• Known severe allergy to the specific drug being considered
• Recent stroke or heart attack — anti-VEGF drugs are mostly retained within the eye, but a small amount enters the bloodstream, and the doctor may weigh timing carefully
• Pregnancy — treatment is generally deferred or discussed carefully, as safety data in pregnancy are limited

Whether anti-VEGF therapy is appropriate in a specific situation is a clinical decision made by the retina specialist together with the patient.

Alternatives and Combination Treatments

Anti-VEGF injections are not the only option for retinal disease. Depending on the condition, alternatives or additional treatments may be considered.

Laser Photocoagulation

Laser treatment was the main treatment for many retinal conditions before anti-VEGF therapy. It still has an important role, especially in some forms of diabetic retinopathy and in retinal vein occlusion. In some cases, laser is used in addition to injections rather than instead of them.

Photodynamic Therapy (PDT)

PDT uses a light-activated drug given through a vein, followed by a low-energy laser applied to the eye. It is used in selected conditions such as central serous chorioretinopathy and, occasionally, in polypoidal choroidal vasculopathy, sometimes in combination with anti-VEGF injections.

Intravitreal Steroid Injections or Implants

Steroid medication delivered into the eye, either as an injection or as a slow-release implant, can reduce retinal swelling. Steroid options are sometimes considered for diabetic macular edema or vein occlusion when anti-VEGF therapy has not fully worked, or when frequent injections are not practical. Steroids carry their own risks, including raised eye pressure and faster cataract development.

Surgery (Vitrectomy)

Vitrectomy — surgery to remove the vitreous — is used in advanced diabetic retinopathy with bleeding into the vitreous, retinal detachment, or scar tissue pulling on the retina. It may be combined with laser and anti-VEGF treatment.

Managing the Underlying Condition

For diabetes-related retinal disease, controlling blood sugar, blood pressure, and cholesterol is fundamental and works alongside any eye treatment. For AMD, certain vitamin and mineral supplement combinations (often called “AREDS2” formulas) are recommended for some patients with intermediate dry AMD to reduce the risk of progression to wet AMD — this is a separate discussion with the eye doctor.

Preparing for an Anti-VEGF Injection

Preparation for an anti-VEGF injection is straightforward. Most people are able to continue their normal routine before the appointment.

Before the Appointment

• Medications: Most regular medicines, including blood thinners such as aspirin or warfarin, can usually be continued. Tell the eye doctor about all medications you are taking, but do not stop blood thinners on your own.
• Eye drops or makeup: Avoid eye makeup on the day of the procedure. If you have any eye drops in use, mention them.
• Symptoms of infection: If you have a stye, conjunctivitis, or any eye infection in the days before the injection, let the clinic know so they can decide whether to postpone.
• Driving: Arrange for someone to bring you home or use other transport. Your vision will be temporarily blurred from the dilating drops and from the disinfectant used during the procedure.
• Eating and drinking: No fasting is needed. Eat and drink normally.

On the Day of the Injection

When you arrive, you will usually be checked in and have your vision and eye pressure measured. Drops are placed to dilate the pupil so the retina can be examined again if needed, and anaesthetic drops are used to numb the surface of the eye. Sometimes additional numbing is given with a small cotton applicator or a jelly applied to the white of the eye.

What Happens During the Procedure

The injection itself takes only a few seconds, although the full visit may last an hour or more once preparation, waiting, and post-injection checks are included.

1. Positioning: You will lie back or recline in a chair with your head supported.
2. Cleaning the eye: The skin around the eye and the surface of the eye are cleaned with an antiseptic, usually povidone-iodine. This step is crucial for reducing the risk of infection. The antiseptic may sting briefly.
3. Eyelid holder: A small instrument called a speculum is gently placed to hold the eyelids open so you do not need to worry about blinking.
4. The injection: The doctor will ask you to look in a specific direction. A very fine needle is used to inject a small amount of the medicine through the white of the eye into the vitreous cavity. Most people feel a brief pressure or pinch rather than a sharp pain.
5. After the injection: The speculum is removed, the eye is rinsed if needed, and the eye is checked. The whole injection part typically takes less than a minute.

You may notice floaters, small bubbles, or a shadow in your vision immediately afterwards. This is normal and is usually due to the medicine itself or a small air bubble, and it settles over hours to a few days.

Recovery and Aftercare

Most people are able to go home shortly after the injection. Recovery from a single injection is usually quick, but there are several things to be aware of.

The First 24 to 48 Hours

• Mild discomfort: A gritty or scratchy feeling is common as the surface of the eye recovers from the antiseptic. Lubricating drops (artificial tears) often help.
• Red spot on the eye: A small red patch on the white of the eye where the needle entered is normal. It usually fades over one to two weeks, similar to a bruise.
• Floaters: Small spots or strands in vision are common in the first day or two.
• Blurry vision: Vision may be blurry for several hours, partly from the dilating drops and partly from the iodine antiseptic.

What to Watch For

Although serious complications are uncommon, certain symptoms should prompt urgent contact with the eye clinic or emergency care:

• Increasing pain in the eye, especially if it gets worse after the first day
• Worsening redness
• Significant or sudden drop in vision
• Sensitivity to light that is getting worse rather than better
• Sticky discharge from the eye
• A sudden increase in floaters or flashes of light, or a curtain or shadow across the vision

These can be signs of infection, increased eye pressure, inflammation, or retinal detachment and need to be checked quickly.

Activity After the Injection

Most clinics ask patients to avoid rubbing the eye, swimming, or using contact lenses for a short period. Normal activities such as reading, watching television, light cooking, and walking are usually fine the same day or the next day. Driving on the day of the injection is generally not advised because of blurred vision.

The Long-term Treatment Schedule

One of the most important things to understand about anti-VEGF therapy is that it is rarely a one-time treatment. Most retinal conditions treated with these injections need ongoing therapy, sometimes for years.

Loading Phase

Maintenance Phase

After the loading phase, different schedules may be used to maintain the response while minimising the number of injections:

• Fixed interval: Injections are given at regular intervals (for example, every 8 weeks), regardless of the appearance of the retina at each visit.
• Pro re nata (PRN), or “as needed”: Injections are given only when imaging shows new fluid or other signs of disease activity. This requires frequent monitoring visits.
• Treat and extend: The interval between injections is gradually lengthened as long as the retina stays dry, and shortened again if fluid returns. This approach is widely used and aims to balance disease control with fewer visits.

The right schedule depends on the condition, the drug, and individual response. Major retinal societies endorse treat-and-extend and fixed-interval approaches as effective frameworks, and the specific plan is tailored by the retina specialist over time.

Monitoring

At follow-up visits, the doctor will typically:

• Check vision
• Examine the retina
• Perform an OCT scan to look for fluid or thickening
• Sometimes repeat angiography

Based on these findings, the next injection is given, deferred, or the interval is adjusted.

Risks and Complications

Anti-VEGF injections have a strong overall safety record, but no procedure is without risk. Risks fall into several categories.

Common, Usually Minor Effects

• Subconjunctival haemorrhage — a red patch on the white of the eye that fades over one to two weeks
• Gritty feeling or mild irritation from the antiseptic
• Floaters or air bubbles in vision for a day or two
• Brief rise in eye pressure right after the injection, which usually settles on its own

Less Common but Serious Risks

• Endophthalmitis: A severe infection inside the eye. This is rare — reported in roughly 1 in several thousand injections in published series — but it is the most feared complication because it can threaten vision. Strict sterile technique and antiseptic preparation are used to keep this risk as low as possible. Symptoms typically appear within a few days of the injection and include increasing pain, redness, and worsening vision.
• Retinal detachment: Very rare, but possible.
• Vitreous haemorrhage: Bleeding into the vitreous, which can cause sudden floaters or vision loss.
• Lens injury or cataract: Uncommon, especially with experienced injectors.
• Sustained rise in eye pressure: Particularly in people with glaucoma or those receiving frequent injections.
• Intraocular inflammation: Some drugs have a higher reported rate of inflammation than others; if this occurs, switching agents is often considered.

Systemic (Whole-body) Risks

Small amounts of anti-VEGF medicine reach the bloodstream after intraocular injection. There has been ongoing study of whether this slightly increases the risk of cardiovascular events such as heart attack or stroke, particularly in people with existing risk factors. Large clinical trials and analyses have not shown a clear, consistent increase in these events with most agents, but the question continues to be researched and is part of the conversation with the retina specialist for patients with significant heart or stroke history.

Life During Long-term Anti-VEGF Treatment

Being on anti-VEGF treatment usually means committing to regular eye appointments over a long period. Understanding this practical reality is part of getting the best result.

Attendance and Consistency

Studies of real-world outcomes consistently show that missed appointments and longer-than-recommended gaps between injections are associated with worse vision results, particularly in wet AMD and DME. Keeping to the treatment schedule is one of the most important things a patient can do.

Daily Life and Activities

Between injections, most people return to their normal lives. There are usually no restrictions on reading, screen use, exercise, travel, or work outside of the immediate post-injection period.

Monitoring Vision at Home

Managing the Underlying Condition

For diabetes-related disease, blood sugar, blood pressure, cholesterol, and kidney function need ongoing attention. For AMD, not smoking, eating a diet rich in leafy greens and fish, protecting the eyes from strong sunlight, and discussing AREDS2-type supplements with the eye doctor are part of the overall plan. Conditions in the second eye are also monitored, since AMD and diabetic retinopathy often affect both eyes over time.

Emotional and Practical Aspects

Repeated eye injections can be tiring and stressful, even when the procedure itself is well tolerated. Some people feel anxious before each visit; this is very common and usually eases over time. Talking to the clinic about anxiety, asking for extra numbing, or scheduling injections at a less stressful time of day can all help. Family support during appointments, especially in the first few visits, is valuable.

Anti-VEGF Injections in Children

Although anti-VEGF treatment is mainly used in adults, it has an important role in babies with retinopathy of prematurity (ROP), a condition that can affect very premature or low-birth-weight infants. In ROP, abnormal blood vessels grow in the developing retina and can lead to retinal detachment and blindness if not treated.

For selected patterns of ROP, anti-VEGF injections are used either alongside or instead of laser treatment. Compared with laser, anti-VEGF treatment in ROP:

• Is quicker to deliver and may be better tolerated in very sick infants
• Allows the peripheral retina to continue developing
• Carries a risk of late reactivation of disease, which means babies need careful, prolonged follow-up

The dose used in babies is much smaller than in adults, and the choice between anti-VEGF and laser depends on the type and location of ROP, the baby’s general health, and the availability of follow-up. Decisions are made by paediatric ophthalmologists or retinal specialists experienced in ROP.

Anti-VEGF injections are also used in rarer paediatric conditions involving abnormal retinal vessels, such as familial exudative vitreoretinopathy and Coats disease, on a case-by-case basis.

What to Look for in a Retina Specialist

Anti-VEGF injections are usually given by retina specialists or by ophthalmologists with specific training in retinal disease. When choosing where to have treatment, useful questions to consider include:

• Does the centre have experience with the specific condition being treated?
• Is OCT and other retinal imaging available on-site for monitoring?
• What is the process if a complication occurs, such as suspected infection, including out-of-hours contact?
• How is the long-term injection schedule planned and communicated?
• What other treatments (laser, surgery, steroid implants) are available if needed?

Meeting the team, understanding the planned schedule, and feeling comfortable asking questions all matter when treatment may last for years.

Frequently Asked Questions

Does the injection hurt?

Most people describe the injection as a brief pressure or a quick pinch rather than a sharp pain. Anaesthetic drops and sometimes additional numbing are used. The antiseptic used to clean the eye can cause more discomfort afterwards than the injection itself. If pain is a barrier, the clinic can usually adjust the numbing method.

Will I see the needle coming towards my eye?

You are asked to look in a specific direction during the injection, away from the needle, so you do not see it approaching. You may notice the doctor’s hand and some movement, but the needle itself is usually not visible to you.

How many injections will I need?

This varies widely. Some people need only a few injections; others need ongoing treatment over many years. The number depends on the condition, the drug, and how the eye responds. Many people receive between six and ten injections in the first year and fewer in later years as intervals are extended.

Can I stop the injections once my vision improves?

Stopping injections too early often leads to recurrence of the disease and loss of any vision gained. The decision about when, or whether, to space out or stop treatment is based on imaging and examination findings and is made gradually over time, not based on how you feel alone.

Will the injections cure my disease?

Anti-VEGF injections control disease activity rather than cure the underlying condition. They reduce fluid and abnormal vessels and protect vision, but the disease process — AMD, diabetic damage, vein blockage — remains, and treatment is generally continued as long as it is helping.

Can both eyes be injected on the same day?

Yes, both eyes are sometimes treated on the same day, using separate sterile setups and sometimes separate drug vials. Whether to inject both eyes at once depends on logistics, the condition, and the clinic’s protocol.

Can I fly or travel after an injection?

Air travel is generally safe after an anti-VEGF injection, though many doctors prefer that patients wait until the next day so any early problems can be checked. Discuss travel plans with the clinic, especially for longer trips that might affect the next scheduled injection.

Will the injection affect my cataract surgery or other eye procedures?

Anti-VEGF injections do not prevent cataract surgery or most other eye procedures. The timing of cataract surgery in someone on injections is planned by the eye team to keep retinal disease well controlled around the time of surgery.

Are anti-VEGF injections safe during pregnancy or breastfeeding?

Because VEGF is important for normal blood vessel development, anti-VEGF drugs are generally avoided in pregnancy unless the benefit clearly outweighs the risk. The use of these drugs during breastfeeding is also approached cautiously. These situations need an individual discussion with the eye doctor and, where relevant, the obstetrician.

What is the difference between “wet” and “dry” AMD, and do injections help both?

Dry AMD involves gradual thinning and damage to the macula without abnormal new vessels. Anti-VEGF injections are not used for dry AMD. Wet AMD involves abnormal vessels and leakage; anti-VEGF injections are the standard treatment for this form. Dry AMD can progress to wet AMD over time, which is one reason regular monitoring is important.

Conclusion

Anti-VEGF intravitreal injections have transformed the treatment of several serious retinal diseases. For many people, these injections offer the best available chance of preserving or improving central vision in conditions that once led to severe and lasting vision loss. The procedure itself is brief and well tolerated, the safety record is strong, and a range of drug options allows treatment to be adapted over time.

What requires the most adjustment for most patients is not the injection but the commitment to regular visits, careful monitoring, and management of the underlying condition over months or years. Working closely with a retina specialist, attending scheduled appointments, watching for warning symptoms, and looking after general health all contribute to the best long-term outcome. With this combination of treatment and follow-up, many people are able to continue reading, driving, working, and enjoying daily life despite a serious retinal diagnosis.