Selective laser trabeculoplasty
Information for patients from Ophthalmology
Your doctor / consultant has diagnosed you with open angle glaucoma that needs a laser treatment. This leaflet will explain the following.
What open angle glaucoma is.
What causes the condition.
What the treatment options and alternatives are.
What the risks and benefits are to having treatment.
What happens during treatment.
How to look after your eye at home.
We hope this leaflet answers some of the questions you may have. If you have any further questions or concerns, please speak to a member of your healthcare team.
What is open angle glaucoma?
Open angle glaucoma is a chronic (persistent / longstanding) type of glaucoma affecting the optic nerve. The optic nerve carries images from the retina (lining of the back of the eye) to the brain.
In most glaucoma patients the normal fluid pressure within the eye slowly raises, putting pressure on the optic nerve fibres. The normal fluid pressure is known as intraocular pressure or IOP.
What causes the pressure to increase?
The fluid (aqueous humor) within your eyes helps to bathe and nourish the:
lens (behind the pupil);
iris (coloured part inside the front of the eye); and
cornea (clear area at the front of the eye).
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The tissues around the lens produce the fluid. It drains out of the eye through a meshwork of tissues called the trabecular meshwork. The trabecular meshwork is at the outer edge of the iris. The fluid then drains into your bloodstream. The drainage channels can become slowly blocked, so the fluid cannot drain away properly and the pressure builds up.
How is the condition treated?
Most people with open angle glaucoma are treated with eye drops. Eye drops lower the pressure in the eye by:
reducing fluid from forming; and / or
improving drainage to stop or reduce nerve damage.
However, sometimes the eye drops do not work on their own and further measures are needed. These include a short course of tablets, laser treatment, or drainage surgery.
What is selective laser trabeculoplasty?
Laser trabeculoplasty is a way of reducing the pressure in your eye. We can sometimes use this treatment alongside eye drops.
We apply laser energy to the drainage tissue in your eye. This starts a chemical and biological change in the tissue. It results in better drainage of fluid through the drain and out of your eye. The effects can vary, and may only last 5 to 10 years.
How long will I have to stay in hospital?
This treatment is performed in an outpatient clinic. You do not need to stay in hospital overnight.
Allow 1 to 2 hours for your appointment.
What happens when I arrive at hospital?
Please report to the department reception shown on your appointment letter. The receptionist will direct you to the clinic, where a member of clinic staff will call you.
What happens during the laser treatment?
You may have a vision test, so it is helpful to bring your distance glasses with you.
If you wear contact lenses, we may ask you to remove them for your appointment. Bring your distance glasses if you have them.
You will usually have drops put in to your eye to make your pupil smaller. It takes about 15 to 30 minutes to constrict your pupil.
We will use anaesthetic drops to numb your eye.
We will ask you to sit with your head forward on the chin and forehead rests of the laser machine.
The ophthalmologist (eye doctor) will place a special lens on the front of your eye. They will direct a beam of laser light at the trabecular meshwork, which may dazzle you.
After laser treatment, you may have drops to prevent a rise in pressure.
Will the procedure hurt?
You may feel some discomfort during your treatment.
What happens after selective laser trabeculoplasty?
The pupil constricting drops may give you a headache, so take your usual painkillers if needed. Usual painkillers can include paracetamol or ibuprofen.
The drops can also affect your vision, making your vision temporarily more clear or sometimes more blurred. These effects should wear off within a few hours.
Will I need a follow-up appointment?
Most patients have a follow-up appointment in the Eye Clinic, to check their condition. After your treatment the ophthalmologist will give you a slip to take to reception for them to book this appointment.
When can I drive again?
Do not drive or operate machinery until the effects of the drops and bright lights have worn off. Arrange for someone to collect you after your treatment and take you home. You can use public transport.
How do I look after my eye at home?
We may prescribe you eye drops for 1 to 2 weeks. Leave at least 5 minutes between different eye drop medication.
Continue using any normal eye drops, as before.
What should I do if my eye hurts at home?
Please contact your consultant's secretary if you:
have any concerns
feel any pain, or
have reduced vision for more than 24 hours after your laser treatment.
The secretary's phone number is on your appointment letter.
What risks are involved?
Rarely, there may be a rise in intraocular pressure. This can cause some pain and clouding of your vision.
A short period of inflammation of your iris.
A small risk of bleeding.
Blockage of the drainage angle, if your cornea and iris stick together due to inflammation. If this happens you may need further laser treatment.
What happens if I do not have treatment?
If left untreated, the rise in pressure may lead to loss of peripheral vision as the fibres die. There is a possibility that this could lead to blindness.
Further information
[Web sites last accessed 11 March 2026]
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