The day of an intravitreal anti-VEGF injection

Anti-VEGF medicine is placed into the vitreous for some macular new vessels or macular oedema, such as wet age-related macular degeneration, diabetic macular oedema, macular oedema from retinal vein occlusion, or myopic choroidal neovascularisation. Whether it suits you, which Hong Kong-registered product, how many injections and how far apart, must be decided by an ophthalmologist after a dilated fundus exam and optical coherence tomography. This page only describes what you feel, in order, on the day. It does not sell a medicine, compare products, or promise that vision will improve or that lost vision will return. The international nonproprietary-name table is on Intravitreal anti-VEGF injection.

If you take a blood thinner, are allergic to the antiseptic or to anaesthetic, or are pregnant or planning pregnancy: say so before it starts. This page does not tell you to stop a medicine yourself.

The order of the day

1. The eye and the medicine already prescribed for you are checked. The doctor may look again at a recent scan.
2. Numbing drops. Some people also have a small pad of anaesthetic on the white of the eye. The eye becomes less sensitive.
3. Antiseptic is used on the white of the eye and near the injection. Most people feel a sting that passes. If you know you are allergic to that kind of antiseptic, say so beforehand so the doctor can use the method they specify. Do not switch to plain water yourself.
4. The lids are held gently open. Look where you are asked. Try not to talk and not to touch the eye, so droplets are less likely to land on it.
5. The medicine goes into the vitreous. Most people feel a brief pressure or fullness, not a long severe pain. If it hurts a lot, say so.
6. Afterwards the doctor checks whether you can see a hand or a light, and may measure the pressure. A small round shadow or bubble can appear briefly.
7. Most people leave the same day. Whether to continue your usual drops, and whether you can drive, follows that day’s vision and the doctor’s instruction. This page has no drop timetable.

Diagrams

Risks and complications

No new percentages. The existing injection page already says these are education notes, not a clinic’s statistics.

• A red patch on the white of the eye: common, and it usually fades.
• Floaters, a gritty feeling, a small bubble: common.
• A short rise in eye pressure can happen soon after the injection. If you already have glaucoma, tell the doctor.
• After many injections, some people have pressure that stays high and needs glaucoma-style follow-up.
• Endophthalmitis: uncommon, but an emergency. The more injections over a lifetime, the more that added chance needs to be taken seriously. This is not your personal probability.
• Sterile inflammation inside the eye: uncommon. It can look like infection. A doctor must tell them apart. Do not decide it is “just irritation”.
• Touching your own lens and causing cataract: uncommon.
• Vitreous haemorrhage: uncommon.
• Retinal tear or detachment: uncommon.
• Retinal artery occlusion: extremely rare. Sudden blindness is an emergency.
• A link between long-term injections and macular atrophy is discussed in the literature. That is part of the doctor’s judgement, not a reason to stop the injections yourself.
• Product labels mention a theoretical risk of arterial clots. Large studies do not agree about stroke or heart attack. Tell the doctor about cardiovascular disease. Do not stop a prescribed medicine yourself.
• Pregnancy or planning pregnancy: most products lack enough data. This needs an individual discussion.

Afterwards: which path

Expected, and you still attend review: mild grittiness, one small dark spot, a red patch on the white, vision a little dim that day.

Prompt ophthalmic assessment (same day if possible): new flashes, or a clear increase in floaters, without a curtain, without sudden blindness, and without severe pain.