In macular degeneration, degenerative changes in the retina cause abnormal blood vessels to grow into the retina from beneath. These leak and bleed into the retina, damaging vision. They form because the retina releases a chemical, VEGF. Eventually, these abnormal blood vessels can scar which can lead to a permanent loss of vision if treatment is not sought. Mr Jonathan Dowler, a leading ophthalmologist and expert in treating macular degeneration, gives us a Q&A about injection treatments.
How does treatment work?
The drug stops leakage and shrink the blood vessels by neutralising VEGF, and provided not too much damage has already been done, vision is stabilised or improved. This is injected into the eye.
What will happen if I don’t have treatment?
You will lose some vision; not all vision, but the central vision will decline on average to the point at which you are only able to count fingers.
What will happen if I have the treatment?
There is a 90% chance your vision will be stabilised and a 30% chance your vision will double. Most patients have a measurable improvement in their vision.
What does the treatment involve?
You lie on a couch in a treatment room. Anaesthetic and antiseptic drops are put in the eye. The treating doctor will scrub up, clean the skin, put a plastic sheet round the eye, hold the eyelids open with a clip, and ask you to look in a particular direction and to keep your head and eye still. The injection is then given. Although an injection into the eye sounds bad, often there is no pain at all, and at worst, it is no worse than giving blood. The drape and clip are then removed. Treatment takes about 10 minutes in total.
What ‘dos’ and ‘don’ts’ are there following treatment?
Generally, you are free to do all normal activities immediately following injection. Use any drops provided as directed after the treatment. For three days avoid direct pressure on the eye and do not use contact lenses. You can however fly immediately after the injection; it is not advisable, however, to travel to a place where if problems were to arise, there are no facilities to deal competently with them.
Do I have to have a treatment at every visit?
There are three main approaches to treating macular degeneration:
- Continuous: an injection every visit. This may be appropriate if you have poor vision in the eye, or disease recurs whenever treatment is stopped.
- As-required: you are reviewed regularly and frequently and treatment is applied if disease is active.
- Treat-and-extend: you are treated at each visit; if the disease is active the interval to the next injection is shortened, if it is inactive the interval is increased.
Approaches two and three depend on changing treatment when the disease worsens. Any reduction in vision associated with this may not be reversible. Provided treatment and review are regular, however, it seems that the three approaches lead to similar results.
How long does a treatment last?
This varies according to the patient and the drug, but between 1-2 months is typical, so if the problem is still active, treatment will need to be repeated after that interval.
How many treatments will I need?
Though dependent on the drug, on average treatment will require 7-8 injections in the first year and 5-6 per year thereafter.
When can I stop treatment?
Treatment and surveillance are lifelong and the outcome is best if visits are regular and frequent.
What is the long term outlook with treatment?
Treatment is effective in controlling leakage and stabilising vision over many years, provided visits are frequent and regular. If vision does decline, the commonest cause is a slow progressive loss of tissue (dry change), which is not treatable.
What are the risks of treatment?
The risks of treatment are few and the main concern is infection. This happens in around 1 in 1000 cases. Other risks include short-term rises in the pressure of the eye, retinal detachment, cataracts, inflammation and bleeding into the eye. Sometimes the treatment can cause contraction of one of the retinal layers, which tears, causing sudden loss of vision.
How will I know if there is a serious problem after treatment?
If there is an infection, on average three days after treatment (though it may occur as soon as one day after treatment), the eye becomes very painful, and vision goes down sharply. Sight can be completely lost if not treated.
What should I do if there is a problem after the treatment?
You should make contact as soon as possible with either:
- The treating doctor
- The eye centre
- Matron’s office at the London clinic
If it is quicker, go straight to an eye casualty centre such as Moorfields Eye Hospital or the Western Ophthalmic Hospital.
What could happen after the injection that is not a serious problem?
- The eye may be sore and gritty for a day or so after injection. This is usually the consequence of the iodine cleaning solution used. It is a chemical injury, not an allergy. Many patients think they have an iodine allergy, but most do not. If the iodine is not used, there is a much greater risk of infection. Treatment with lubricant drops helps this to settle.
- Bleeding from the injection point, causing a red eye. This settles on its own, though it can take a week or two to do so.
- Specks, blobs, floaters in the vision usually settle after a day or so. Sometimes a circular black blob can be seen at the bottom of your vision; this is an air bubble and will go in a few hours.
Are there any other treatments for this problem?
Who should not have injections?
You should not have injections if:
- You have an allergy to the drug (rare)
- You have an eye infection, or some severe infections in the body
Injections may be stopped if:
- You have had a stroke or heart attack in the last three months
- You have uncontrolled angina or blood pressure
You must let the doctor know if there is any change to your medical condition.
Will the treatment interfere with any of the medicines I take?
Generally, no, but you must let the doctor know what medicines you are taking.
Can the medicines I take worsen my eye condition?
Blood thinning agents, such as aspirin, clopidogrel, warfarin, and riveroxaban are considered safe to use in patients having injections. They do not increase the risk of bleeding into the eye from macular degeneration, but if you do have a bleed, they can make it larger.
You must tell the doctor if you are taking these drugs.
Will the treatment cure the problem?
No, treatment can only contain it. This is why repeated visits are required. There is currently no way of preventing the disease from coming back.
What happens if the treatment doesn’t work?
Sometimes a drug will cease to have an effect – for example if a treatment is given and after a month the disease has progressed. Usually changing the drug will get the disease back under control.