Selective Laser Trabeculoplasty

Selective Laser Trabeculoplasty

Selective Laser Trabeculoplasty, or SLT, is a form of laser surgery that is used to treat high eye pressure in glaucoma. It can be used as:

  • Initial treatment for glaucoma
  • Adjunct to eye drops when eye drops are not lowering the eye pressure enough or are causing significant side effects.

SLT can help to avoid using multiple drops for the eye pressure and the need for glaucoma surgery. Mr. Ellabban will assess you and advise if you SLT can help you.

How does SLT work?

The laser energy is applied to the trabecular meshwork (the drainage tissue in front of the eye). This will induce some biological reactions that can help in better drainage of fluid through the trabecular meshwork and out of the eye. This eventually results in lowering the eye pressure.

It may take 1-3 months for the full treatment effect to appear. The doctor may decide to treat half of the tissue on the first treatment, then treat the second half at a later date. In general, SLT is successful in about three out of four (75%) patients.

It is important to remember that this laser treatment is performed to save the sight you still have. It will not improve your vision or restore any sight you may have already lost.

How is SLT performed?

The treatment is performed at the eye outpatient clinic. The nurse will put some drops to make your pupils small. Then you will be taken to the laser room. You will be asked to sit on a machine very similar to the eye examination machine.

Mr Ellabban will put some numbing drops and put a contact lens to stabilise the eye and perform the laser. The treatment takes about 10 minutes to treat one eye.

During the laser treatment, you may hear some clicking noises and you may see some bright lights or flashes. The doctor may put some drops to lower the eye pressure before or after the laser treatment. The treatment is not painful in most cases.

What are the risks of SLT?

SLT has a good safety profile and the risk are rare. However, like any procedures, there is a small risk of as:

  • Mild inflammation is common after laser and can be treated with some anti-inflammatory drops.
  • Temporary elevation of the eye pressure after laser. It can occur in about 5 % and usually resolves in 1-2 days.

How effective is SLT?

The research found that SLT can lower eye pressure by about 30% when used as the first treatment (this is comparable to the pressure-lowering effect of the commonly used eye pressure drops). The effect will generally last between 1-5 years or sometimes longer. This effect may vary according to the type of glaucoma. This effect may be reduced if you are already using glaucoma medications.

What is the aftercare?

Following the laser treatment, you will be asked to wait for 30-40 minutes for the doctor to check the eye pressure. You may feel your eyes are a little bit sore or red which often resolve in a few hours. You will be given some anti-inflammatory drops to use at home for 1-2 weeks after the laser procedure. You can return to work and your usual activities the next day.

If you are using glaucoma drops to the treated eye, you should continue using them till the doctor advise you. The doctor will arrange to review you again in 3-4 weeks to check the eye pressure and to make sure the laser is working.


Why SLT is called Selective?

This laser targets only the pigmented tissue in the trabecular meshwork (the drainage tissue in front of the eye), hence called “selective”.

What happens if it wears off?

The effect of SLT on eye pressure wears off after several years. If so, laser treatment can be repeated. Nearly half of patients will require repeat treatment after 5 years. Repeat treatments don’t always lower IOP as much, and continued repeat laser will eventually not be effective.

In general, if SLT is not initially successful, repeat treatment is not likely to be effective.

What happens if SLT doesn’t work?

If SLT fails to lower the IOP, then the glaucoma is treated by other means such as medications or surgery. The laser does not affect the success of these other types of treatment.

Will I still need to use glaucoma medications?

Some patients can be controlled with just laser treatment. Others may require additional eye pressure lowering to achieve the target eye pressure. Therefore, they may need to use glaucoma medication as well.