Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty (SLT): A Laser Procedure to Lower Eye Pressure

What is SLT?

SLT is a laser procedure performed in the office to lower eye pressure.

How does SLT work?

Laser energy is applied to the trabecular meshwork. The trabecular meshwork is located in the front of the eye and is the natural drain for fluid. SLT stimulates the trabecular meshwork to increase the amount of fluid drained from within the eye, which lowers eye pressure. It may take up to 2 months for the laser to take its full effect.

Who needs SLT?

Patients with open-angle glaucoma who need improvement in eye pressure control. This can be used alone or as an addition to eye drops.

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What are the benefits?

On average, SLT can lower the eye pressure by about 20-30%. The laser is effective in lowering eye pressure in about 80% of patients. The laser effect wears off after several years, but the trabecular meshwork can be stimulated again with repeat laser. SLT does not affect the success rates or the eligibility of getting other medical or surgical treatments.

What are the risks?

Compared to many other treatments for glaucoma, including eye drops, other laser treatments and surgery, SLT has few side effects. Inflammation is possible after the laser but it is not common. You may be prescribed anti-inflammatory drops on an individual basis. There is a small risk of temporary high eye pressures shortly following the laser treatment. This is usually controlled with glaucoma medications.

Will SLT cure my glaucoma?

The simple answer is “No”. Glaucoma is a chronic disease that requires constant monitoring and treatment. The SLT procedure will help to lower your eye pressure. However, it will not reverse any loss of vision that has already occurred.



What should I expect if I have an SLT?

Your treatment will be performed in a specially equipped laser room in the clinic. Once you have been checked in, drops will be used to numb your eye and check the pressure. No injections or needles will be used.

  • First, you will receive an eye drop called apraclonidine, which helps prevent a rise in the eye pressure after the procedure. Then a drop of anesthetic will be applied to numb the eye.
  • Your doctor will place a special lens on your eye to help focus the laser on the trabecular meshwork. This lens also prevents your eye from blinking and keeps the eye still during the treatment. A clear gel is placed between the eye and the lens to protect the surface of your eye.
  • You will then hear a series of clicks and may see flashes of light as the laser treats your eye. There is virtually no pain with the procedure. You will feel the lens slowly rotating on the surface of the eye as the doctor treats various parts of the trabecular meshwork. The procedure generally takes 5-10 minutes.

What should I expect after SLT?

At the end of the laser treatment, the lens will be removed from the eye. The gel may remain on your eye for up to an hour, leading to blurred vision or a feeling of heaviness. As a safety measure, your eye pressure will be checked sometime after your procedure.

How long after the laser I will be seen?

Depending on the type and severity of your glaucoma you will be seen 1-6 weeks after the laser.

What eye drops will I use after the laser procedure?

Your doctor may ask you to use an anti-inflammatory eye drop in the treated eye for several days.

Can I stop my glaucoma drops after the laser procedure?

Your doctor will tell you which drops to continue using and how often after the laser procedure. Sometimes patients are able to reduce the number of eye drops they are taking. Even if you are taking the same glaucoma medications after the procedure, the surgery is a success if your pressure is lower. The need for eye drops long-term after this treatment varies greatly and depends on your type of glaucoma and the rate at which it is progressing.

Will my vision improve after the laser procedure? 

This laser is for lowering the eye pressure and will not improve your vision.

What is the recovery time and what should I expect?

  • Though everyone heals differently, most people can resume normal activities right after treatment, although you'll need to have someone drive you home. For the next few days your eyes may be red, a little scratchy and sensitive to light if you develop inflammation in the eye after the procedure
  • If there is any blurred vision, it usually improves within hours or a day.
  • There are no restrictions in reading, watching TV, using your phone, tablet device, computer, etc but you may tire more easily during these activities.
  • Tylenol (acetaminophen) is a good option if you feel any pain or discomfort unless you are unable to take this medication.
  • If your eye has severe pain or sudden worsening pain or vision after surgery, please call our office or on call physician immediately.

Will SLT cure my glaucoma?

The simple answer is “No”. Glaucoma is a chronic disease that requires constant monitoring and treatment. The SLT procedure will help to lower your eye pressure. However, it will not reverse any loss of vision that has already occurred.


For more information, please see:

American Academy of Ophthalmology patient information website

American Glaucoma Society patient information website