Selective Laser Trabeculoplasty (SLT)
There are different ways in which laser therapy can be used to treat patients with glaucoma. Selective laser trabeculoplasty is a treatment for patients who have open angle glaucoma
If you have healthy eyes, the fluid in your eye (aqueous humour) flows through your pupil into the front of your eye. It then drains away through drainage channels inside the eye called the trabecular meshwork. These drainage channels are situated in the angle of the eye, which is where cornea (clear front layer of the eye) and iris (coloured part of the eye) meet.
However, in some eyes these drainage channels do not work properly, so your eye pressure increases. This increase in pressure may injure your optic nerve (the nerve that carries information from your eye to your brain) and impair your vision. This is called glaucoma.
In this trabeculoplasty procedure, a laser beam is applied to the drainage channels to unclog them. This means the aqueous humour flows through the channels better, reducing the pressure in your eye.
The treatment may be helpful in
Lowering the eye pressure and so the need for further additional medication
As an initial glaucoma treatment without the side effects or difficulties of taking eye drops.
Aqueous humour is a completely different fluid to your tears which will not be affected by this laser treatment.
Why should I have this treatment?
It is important to remember that this procedure is performed to save the sight you still have. It will not restore any sight you may have already lost or improve your sight. Some people respond better to the treatment than others and it is successful in about three out of four patients. If the treatment is successful, you may be able to reduce the number of eye drops you currently use to manage your glaucoma.
The treatment is not permanent, and may need to be repeated in the future to control the eye pressure adequately. If this happens the results may not be as good as you experienced after the first treatment. You might need to continue with eye drop treatment as well and, in some cases we may recommend other treatments including surgery if we’re not happy with the pressure.
Are there any risks associated with a selective laser trabeculoplasty?
Complications after this treatment are uncommon. Occasionally your eye pressure will rise immediately after laser treatment. If this happens, you may need extra treatment before you can go home. This treatment usually comes in the form of eye drops, but may come in the form of tablets. We will let you know which treatment you need and will advise you of how long you need to take the treatment for. If we do treat you with eye drops, we will put them in your eye before you leave hospital. You will be asked to remain in the department until your eye pressure has reduced to a satisfactory level. This should take a few hours at most.
Other complications are haemorrhage in the eye, which will blur your vision for a few days or your eye may feel slightly bruised afterwards because of inflammation – this is usually small and can be treated with more frequent steroid drops.
Discomfort - You may wish to take a mild painkiller, for example Paracetamol, to relieve this discomfort. If you are already taking painkillers for a different condition continue with these, but do not take both.
Certain symptoms could mean that you need to be treated quickly, including:
loss of vision
your eye becoming increasingly red.
If you experience any of these symptoms, telephone us for advice immediately. Or visit your nearest accident and emergency department.
Are there any alternatives?
The alternative to this laser treatment is to start or continue with eye drops to lower the pressure in your eye, or surgery. Ask your doctor if you would like more information.
How can I prepare for selective laser trabeculoplasty?
As this is an outpatient treatment, there are no special preparations required. You can eat and drink as normal, and you must take your usual eye medication on the morning of the laser treatment.
The treatment itself should take about 15 minutes, but you are likely to remain in clinic for 1-2hours.
What happens on the day of treatment?
Upon arrival, we will explain the procedure, and ask you to sign a consent form.
As always, remember to bring a list of your current medications with you to the appointment.
We will then l check your vision and put some drops into your eye to make your pupil smaller and to protect the eye from any spikes in pressure. The drops take up to one hour to work.
A few minutes before the treatment, you will have anaesthetic eye drops put into your eye to gently numb the surface of the eye.
Once seated you will then be asked to rest your chin in front of the laser machine, which is similar to the microscope you will have been examined on in clinic. The doctor will put a special contact lens on your eye before applying the laser beam. This lens allows the doctor to view your eye clearly so he/she can apply the laser to the drainage channels and to help keep your eye still. We will carefully direct a laser beam into your eye. You will see a series of bright lights and you will hear a clicking noise while the treatment is being carried out.
It is very important that you sit and keep your head still during the treatment to avoid damage to other parts of the eye. You may feel slight discomfort, but the treatment is generally painless and should take up to 15 minutes.
After the procedure
Your vision may be slightly blurred for a few hours following your laser treatment. This will settle.
For this reason it is strongly advised that you do not drive home yourself. However, apart from driving, you can resume all other normal activities immediately
After the laser treatment, you will have further drops put in your eyes to help reduce any inflammation caused by the laser. The pressure in your eye will be checked about an hour after the treatment. You may then return home. You will then receive a prescription for drops to take at home and an appointment to come back to the clinic for a review.
An important reminder
You should continue to use all your anti-glaucoma medication unless specifically instructed otherwise.