If you have been diagnosed with glaucoma, you may have been told about a treatment called SLT. Selective Laser Trabeculoplasty, or SLT, is a gentle, repeatable laser that helps lower the pressure inside the eye, often reducing or removing the need for daily eye drops.
At Fakeeh University Hospital, Department of Ophthalmology, this article explains what SLT is, how it works, and the benefits and risks, so you can feel informed and prepared. As always, your own doctor remains the best source of advice for your individual situation.
Glaucoma is a lifelong condition in which the optic nerve, the cable that carries vision from the eye to the brain, is slowly damaged. This is usually caused by raised pressure inside the eye.
Glaucoma often has no symptoms until a significant amount of sight has been lost, and once vision is lost, it cannot be restored. Lowering the pressure inside the eye is currently the only proven way to slow or stop the damage, which is why treating it matters so much.
SLT uses very short, low-energy pulses of laser light to gently stimulate the eye's natural drainage filter, known as the trabecular meshwork. This helps fluid flow out of the eye more easily, which in turn lowers the pressure inside it.
Here is what the procedure involves:
SLT is now recommended as an initial treatment option for glaucoma by leading professional bodies, including the American Academy of Ophthalmology, the Canadian Ophthalmological Society, the European Glaucoma Society, and NICE in the UK.
This is supported by research. In the LiGHT trial, a large clinical study of SLT:
Because SLT does not cause scarring, it can also be safely repeated if its effect fades over time.
For many patients, SLT offers a number of advantages:
Like any procedure, SLT carries some risks, and it is important to understand them:
It is also important to remember that SLT controls glaucoma, but it cannot restore vision that has already been lost. This is exactly why early treatment and regular follow-up are so important.
Before the procedure: Keep using your usual glaucoma drops unless you are told otherwise, and bring a list of all your medicines. You can eat normally. It helps to bring a companion, as your vision may be blurry for a few hours afterwards.
On the day: You will be given a drop to help prevent a pressure rise, along with a numbing drop. A special lens rests gently on your eye. You will see bright flashes and may hear clicking sounds. The procedure is not usually painful.
Afterwards: Mild ache, redness, or light sensitivity for 1 to 3 days is normal, and simple pain relief such as paracetamol can help. It is important to use exactly the drops your doctor prescribes after the laser.
SLT does not work instantly. The pressure in the eye falls gradually, with the full effect usually seen around 6 to 12 weeks after treatment. During this time, your doctor may ask you to continue or add anti-glaucoma drops.
Your follow-up visits are an essential part of your care:
Because glaucoma is a lifelong condition, it is important never to miss a pressure check, even if your eyes feel completely fine.
Contact your ophthalmology team urgently if you experience severe eye pain, a sudden drop in vision, worsening redness, or a headache with nausea or vomiting.
Protecting your sight starts with understanding your condition and the options available to you. At Fakeeh University Hospital, Dr. Hayat Ahmad Khan, Consultant Ophthalmologist, and our ophthalmology team are here to assess your eyes, explain your options, and support you with ongoing care.
If you have questions about glaucoma or SLT, we are here to help.
This article is for general information and supports, but does not replace, the advice of your doctor.
