Wet AMD injections: what anti-VEGF treatment involves

The macula is the small central part of the retina that lets you see fine detail when you look straight ahead. In wet AMD the cells of the macula stop working properly and the body responds by growing new blood vessels to try to fix the problem. These vessels grow in the wrong place and cause swelling and bleeding beneath the macula, which is where the word "wet" comes from. It has nothing to do with whether the eye feels watery.

Both the new vessels and the scarring that follows can damage central vision. RNIB describes wet AMD as capable of developing very quickly, with serious changes to central vision within days or weeks. That time scale explains why the pathway is built around speed: treatment that stops the vessels growing is usually needed before they do too much damage, because sight lost to scarring is usually permanent.

The NHS lists two main treatments for wet AMD: injections of a medicine (anti-VEGF) given directly into the eye, and a light treatment that destroys the vessels responsible. In practice the injections are the treatment most people are offered, and this page concentrates on them.

As new blood vessels grow in the eye, the body produces a chemical that encourages yet more vessel growth. Anti-VEGF drugs (anti-vascular endothelial growth factor drugs) interfere with that chemical and stop the vessels from growing. By doing so they reduce further damage to sight. RNIB says anti-VEGF treatments usually have a high success rate and that in most cases they stop sight getting worse in the short term.

It is worth being realistic about the long term. RNIB notes that vision may gradually worsen even with treatment, but that this happens much more slowly than it would without treatment. The aim is therefore to protect the sight you have for as long as possible rather than to restore normal vision.

There are several different anti-VEGF medicines and they are not identical. Some last longer, which allows a longer gap between injections. Your eye clinic will explain which medicine you will receive, how often you are likely to need it, how your progress will be monitored and what the procedure involves, and discuss the risks so that you can make an informed decision. If you go ahead you will be asked to sign a consent form, and the NHS provides a decision support tool for people who are unsure.

RNIB says a course of three injections, one a month for three months, is normally given to start with. After that the pattern depends on two things: the type of anti-VEGF medicine and how well the treatment is working. Your vision and macula are checked regularly with tests and scans to see how the macula is responding, and if it responds well the injections can be spaced further apart.

It is common to need more injections after the first three. Some people need an injection every month or every few months until the bleeding and swelling are under control and sight is stable, while others go several months without treatment. If the first medicine has not worked well you may be switched to a different one.

The thought of an injection into the eye is unsettling for many people, and RNIB acknowledges that it can be unpleasant. Its advice is that not having treatment can mean losing more of your central vision. If you are frightened, it can help to talk to someone who has had the injections; the Macular Society can put people in touch with a treatment buddy.

Clinic visits are frequent and can be tiring, so practical planning helps. Ask the clinic for your treatment plan and the date of your next treatment or monitoring appointment, and keep a calendar. If getting to the clinic is hard, tell the team, because they may be able to offer advice or support, and relatives or friends can share the journeys.

• Bring a list of your medicines and any eye drops you use.

• Ask who will be seen at each visit; you may not always meet the consultant, as care is led by the consultant but delivered by a wider clinical team.

• Agree in advance who to call if your sight changes between visits.

• If an appointment has not arrived when expected, contact the eye clinic booking team rather than waiting.

RNIB advises that if your vision gets worse while you are waiting for your next treatment or monitoring appointment, you should contact your eye clinic straight away. The NHS gives wider urgent advice for people with AMD: get an urgent opticians appointment or help from NHS 111 if your vision gets suddenly worse, you have a dark curtain or shadow moving across your vision, or your eye is red and painful. The NHS notes that these can be signs of other eye problems that need treating straight away.

If you have dry AMD in one eye and notice a sudden change in sight in either eye, tell your optometrist as soon as possible, because dry AMD can develop into wet AMD and sight-saving treatment may then be possible. Do not wait for the next routine check.

At home, RNIB suggests closing one eye at a time and looking at door frames, window frames or tiles for wavy or distorted lines, and some optometrists provide an Amsler grid for the same purpose.

Ask your optometrist or ophthalmologist whether you can keep driving; this depends on whether your sight meets the DVLA vision standards. RNIB points out that you are required by law to tell the DVLA about an eye condition that affects both eyes, or one eye if you only have sight in that eye.

Some people who have lost a lot of vision from AMD see shapes, colours or figures that are not really there. This is known as Charles Bonnet syndrome. The NHS also lists seeing things that are not there among AMD symptoms, so mention it to your clinic rather than keeping it to yourself.

Low-vision support, lighting advice and counselling are available. RNIB states that with the right support people can live confidently and independently with the condition, and you can ask for help at any time.

The usual route starts with an optometrist, who refers you to an NHS hospital eye clinic or an independent treatment centre providing NHS care. Your optician tells you where you are being referred. Because wet AMD is time-critical, the referral is fast-tracked rather than routine, and the clinic leads on explaining the treatment and its risks.

Some people choose to see a private consultant ophthalmologist instead, or in addition. Private care can offer different appointment times and settings, but the medicines, the scans and the monitoring principles are the same, and long-term adherence to the injection plan matters more than where the first appointment takes place. Ask any provider which anti-VEGF medicine is planned, how follow-up will be arranged and who to contact if sight changes, and ask for costs in writing before committing to a course of treatment.