Selective Laser Trabeculoplasty

What is SLT?

Selective Laser Trabeculoplasty, SLT, is a simple, yet highly effective laser procedure that reduces the intraocular pressure. It is performed in the outpatient clinic and typically takes no more than five minutes to complete, although you will be in the clinic for several hours.

Why is it important to relieve intraocular pressure?

The eye’s aqueous fluid is constantly produced and drained at a balanced rate to ensure the health of the lens and cornea. When this drainage becomes blocked, intraocular pressure increases and damage to the optic nerve can occur (called glaucoma). In order to preserve eyesight, it is critical to decrease and control intraocular pressure.

How does it work?

SLT uses short pulses of low-energy light to target the melanin, or pigment, in specific cells of the affected eye. In response, the body’s natural healing mechanisms go to work to rebuild these cells. This rebuilding process improves drainage and lowers intraocular pressure. The surrounding, non-pigmented cells – as well as the rest of the eye structure – are untouched and undamaged.

Does SLT hurt?

No. SLT is a painless procedure. Your eye may ache a little for a day or two after the procedure, but it should not be painful.

Risks

This procedure is considered to be very safe. There is a small risk that the intraocular pressure could rise immediately after the procedure. Your eye pressure will be checked 30 minutes after the procedure to ensure it is normal. There is also a small risk of inflammation after the laser procedure.

What happens during the procedure?

Prior to treatment, eye drops are administered to prepare the eye and provide mild anaesthesia. These drops may give you a headache. Your clinician will use a contact lens to focus the laser and keep your eyelids open. You do not need to worry about blinking during the procedure. Next, gentle pulses of light are delivered through a specially designed microscope.

How often can I have SLT done?

SLT is gentle, non-thermal and non-invasive – which allows the procedure to be repeated, if necessary. Previously, repeat treatments of laser therapy were either extremely limited or not possible.

Who will benefit from SLT?

If you fit into any of the following categories, you’re a good candidate for SLT:

• If you have primary open angle, pseudoexfoliation, or pigmentary glaucoma
• If you are intolerant of glaucoma medications or have difficulty taking them as prescribed
• If you are currently undergoing glaucoma drug therapy and wish to combine it with SLT
• If it is difficult for you to commit to regular follow-up treatments, due to finances, lack of transportation, or other limitations
• If you have a history of failed ALT (argon laser trabeculoplasty) treatments

What if SLT doesn’t work for me?

SLT lowers intraocular pressure by an average of 25% in 75 to 85% of patients treated. For those that do not respond, other forms of treatment, including traditional drug therapy, can still be highly effective.

What are my other treatment options?

• Drop therapy is the most common form of treatment for open-angle glaucoma; however, there are side effects, and medications aren’t effective for all patients. You must remember to take your eyedrops every day.
• If non-surgical methods fail, surgery may be attempted to create a new drainage channel. Unfortunately, this is a highly invasive procedure with a risk of bleeding and infection.
• Argon laser trabeculoplasty (ALT) was formerly the most widely used laser treatment for glaucoma. There are many problems associated with ALT, including irreversible damage to the eye, along with permanent scarring.

Contacts / Further information

Eye Emergency Clinic (urgent advice): 01223 217778

Appointment Centre: 01223 274580

Specialist Nurses (non-urgent advice): 01223 274889

Please leave a message with your contact details and the nature of the problem, and all calls will be returned.

References / Sources of evidence

• SLT Brochure (opens in a new tab)