Intravitreal Injections:
What to Expect

If your eye doctor has told you that you need an injection into your eye, your first reaction is probably something along the lines of "you want to put a needle where?" It is one of the most common anxieties encountered in vitreoretinal practice.

But here is the truth: intravitreal injections are one of the most frequently performed procedures in all of ophthalmology, and they have transformed outcomes for a range of sight-threatening conditions. Having performed thousands of these injections over more than 15 years, the vast majority of patients find the reality far less frightening than the idea. Many tell us afterward that it was nothing like what they had imagined.

This article walks you through exactly what happens before, during, and after the injection, so you know what to expect.

What Is an Intravitreal Injection?

An intravitreal injection is the delivery of medication directly into the vitreous cavity — the gel-filled space inside the eye. By placing the drug inside the eye rather than giving it as a pill or an intravenous drip, we achieve much higher concentrations of medication exactly where it is needed, with minimal effects on the rest of the body.

The injection is given through the white part of the eye (the sclera), using a very fine needle. The whole procedure takes only a few minutes.

What Conditions Are Treated with Intravitreal Injections?

Intravitreal injections are used to treat a wide range of retinal conditions, including:

• Wet age-related macular degeneration (AMD) — the most common indication. Anti-VEGF injections stop abnormal blood vessel growth and leakage under the retina.
• Diabetic macular oedema — fluid accumulation in the macula caused by diabetes. Both anti-VEGF and steroid injections are used.
• Retinal vein occlusion — blockage of a retinal vein can cause swelling and bleeding in the retina. Anti-VEGF injections reduce the associated macular oedema.
• Myopic choroidal neovascularisation — abnormal blood vessels in highly myopic eyes that respond well to anti-VEGF treatment.
• Diabetic retinopathy — anti-VEGF injections can reduce the growth of abnormal blood vessels in advanced diabetic eye disease.
• Uveitis (eye inflammation) — steroid injections can help control inflammation inside the eye.

What Medications Are Used?

The two main categories of intravitreal medications are:

Anti-VEGF Agents

These block vascular endothelial growth factor (VEGF), a protein that drives the growth of abnormal blood vessels and promotes fluid leakage. The most commonly used agents include:

• Ranibizumab (Lucentis) — one of the first anti-VEGF agents, with a long track record of safety and efficacy.
• Aflibercept (Eylea) — blocks multiple VEGF-related proteins and can be given at longer intervals in some patients.
• Faricimab (Vabysmo) — the newest addition, which targets two pathways (VEGF and Ang-2) and can potentially be given every 12 to 16 weeks in some patients.

Steroid Injections

Corticosteroids such as dexamethasone implant (Ozurdex) and triamcinolone are sometimes used to treat macular oedema associated with diabetes, retinal vein occlusion, or uveitis. The dexamethasone implant is a slow-release device that gradually releases medication over several months.

Your doctor will choose the most appropriate medication based on your specific condition, treatment history, and individual response.

What Happens Before the Injection?

Before your first injection, your doctor will have explained why the injection is recommended and what results you can expect. If you have questions, this is the time to ask them.

On the day of the procedure:

• You do not need to fast. Eat and drink normally.
• Take your usual medications, including blood thinners if prescribed. You do not need to stop aspirin or warfarin for intravitreal injections.
• You can come alone, though some patients prefer to have someone accompany them on the first visit, particularly if they are nervous.
• The procedure is performed in the clinic treatment room. You do not need to go to an operating theatre.

What Happens During the Injection?

Here is a step-by-step description of what to expect. The entire process, from preparation to completion, typically takes about 10 to 15 minutes, with the injection itself lasting only a few seconds.

What Happens After the Injection?

The First Few Hours

Your eye may feel slightly gritty, watery, or irritated. This is normal and usually settles within a few hours. You may notice some redness on the white of your eye at the injection site — this is a small, harmless bruise (subconjunctival haemorrhage) and will resolve on its own over one to two weeks. Your vision may be slightly blurry immediately after, partly from the antiseptic solution and partly from the medication in the eye. This usually clears within hours.

You can resume normal activities the same day, including reading, watching television, and light household tasks.

Eye Drops

Your doctor may prescribe antibiotic eye drops to use for a few days after the injection to reduce infection risk. Follow the instructions provided.

What Are the Risks?

Intravitreal injections are very safe, but like any medical procedure, they carry some risks. It is important to understand these, while also recognising that serious complications are rare.

Common and Minor

• Subconjunctival haemorrhage (red spot on the eye) — harmless and resolves spontaneously.
• Temporary floaters — small spots or shadows from the medication, which clear within hours to days.
• Mild discomfort or grittiness — usually settles within a day.

Uncommon but Important

• Raised eye pressure — some patients experience a temporary increase in eye pressure after the injection. This is usually transient and managed with monitoring or eye drops if needed.
• Inflammation — a mild inflammatory reaction can occasionally occur, causing redness, light sensitivity, or blurred vision. This is usually self-limiting or treated with eye drops.

Rare but Serious

• Endophthalmitis (infection inside the eye) — the most feared complication. Strict antiseptic technique during the procedure is specifically designed to minimise this risk.
• Retinal detachment — extremely rare with modern fine-gauge needles.
• Vitreous haemorrhage — bleeding inside the eye, which is very uncommon.

How Often Will I Need Injections?

This depends on the condition being treated and your individual response:

• Wet AMD — treatment usually starts with three monthly injections (a "loading phase"), followed by ongoing injections at intervals tailored to your response. With newer agents, some patients can be maintained on injections every 8 to 16 weeks. Many patients require treatment for years, sometimes indefinitely, though the frequency often decreases over time.
• Diabetic macular oedema — similar loading phase, with ongoing treatment as needed. Some patients achieve remission and can stop treatment; others require longer-term injections.
• Retinal vein occlusion — treatment duration varies. Some patients need only a few injections; others require ongoing therapy for months to years.
• Myopic CNV — often requires fewer injections than AMD, sometimes just one to three treatments.

Your doctor will monitor your response with regular OCT scans and clinical examinations, adjusting the treatment interval based on how your retina is responding.

Intravitreal injections are one of the most important advances in eye care in the past two decades. They have saved the sight of millions of people worldwide who would otherwise have lost central vision to conditions like wet AMD and diabetic eye disease. The procedure is quick, well-tolerated, and performed routinely in the clinic. If your doctor has recommended intravitreal injections, the potential benefit to your vision is substantial, and the risks, while real, are small.

Frequently Asked Questions

Does an intravitreal injection hurt?

Most patients experience mild discomfort rather than real pain. Anaesthetic drops effectively numb the eye, and the needle used is very fine (30-gauge). On a pain scale of 1 to 10, most patients rate the discomfort at 2 to 3. The most uncomfortable part is usually the antiseptic preparation, not the injection itself.

How long does the injection procedure take?

The entire process from preparation to completion takes about 10 to 15 minutes. The injection itself lasts only a few seconds. You can go home shortly afterward and resume normal activities the same day.

Is it safe to drive after an intravitreal injection?

Your vision may be slightly blurry immediately after the procedure due to the antiseptic solution and the medication dispersing in the eye. Many patients find they can drive, but it is advisable to have someone accompany you for your first injection until you know how your vision is affected. Ask your doctor for specific guidance.

What are the signs of infection after an eye injection?

Watch for increasing pain, worsening vision, and significant redness developing one to five days after the injection. These could indicate endophthalmitis, a rare but serious infection (approximately 1 in 2,000 to 1 in 5,000 per injection). If you experience these symptoms, contact your eye doctor immediately. Early treatment is critical.

Do I need to stop blood thinners before the injection?

No. You do not need to stop aspirin, warfarin, or other blood thinners for intravitreal injections. The needle is very fine and the injection site is in the white of the eye, so the risk of significant bleeding is low. You may develop a small red spot (subconjunctival haemorrhage) at the injection site, which is harmless and resolves on its own.

Will I need injections forever?

This depends on your condition. For wet AMD, many patients require ongoing treatment for years, though the frequency often decreases over time with newer medications. For diabetic macular oedema, some patients achieve remission and can stop treatment. For myopic choroidal neovascularisation, fewer injections are typically needed. Your doctor will regularly assess whether treatment can be reduced or stopped.