When Is Selective Laser Trabeculoplasty Recommended to Treat Glaucoma?
Prescription eye drops aren't the only way to lower eye pressure if you have open-angle glaucoma or high intraocular pressure. Selective laser trabeculoplasty (SLT), a laser procedure that improves eye drainage, may be just as effective.
What Is Selective Laser Trabeculoplasty?
The aqueous humor, the clear fluid inside the eye, nourishes the eye and helps it maintain its round shape. As new fluid is produced, the old fluid exits through the trabecular meshwork, the eye's drainage tissue.
Open-angle glaucoma happens when the aqueous humor doesn't drain properly through the trabecular meshwork. As the fluid backs up, pressure builds inside the eye. Increasing pressure can damage the optic nerve, the pathway from the eyes to the brain. Damage to the nerve is irreversible and can cause permanent vision loss.
During SLT, your ophthalmologist uses low-energy laser light to target pigmented cells in the trabecular meshwork. The laser focuses on these cells only and doesn't harm surrounding cells. The treatment prompts your body to rebuild the cells in the meshwork, which improves drainage in the eye and lowers intraocular pressure.
SLT reduces intraocular pressure in 80% of patients, according to an article published in International Ophthalmology Clinics in 2024. Pressure remained lower for two years in 80% of participants. Although the effects of SLT are temporary, the procedure can be repeated if needed without damaging the eye.
What Happens During SLT?
SLT usually takes less than 10 minutes per eye. Numbing drops are placed in your eye before the procedure begins. You may also receive drops to control eye pressure. After applying a clear gel to the eye, your eye doctor places a contact lens on your eye. The lens helps the laser focus precisely on the pigmented cells in the trabecular meshwork.
The laser your eye doctor uses produces light in a series of short pulses, which may look like flashes of light. After the procedure, your ophthalmologist removes the contact lens. Blurry vision can occur temporarily due to the gel placed in your eye.
You'll need to ask a friend or family member to drive you home after the procedure. In just a day or two, you can return to your normal activities.
The pressure inside the eye doesn't lower immediately after SLT treatment. Changes in eye pressure may take 1 to 3 months, according to the Glaucoma Research Foundation. During follow-up appointments, your eye doctor will monitor your intraocular pressure and determine if the treatment was effective.
When Do Ophthalmologists Recommend SLT?
Your ophthalmologist considers the type and severity of glaucoma before recommending any treatment. SLT may be recommended if:
- You've Just Been Diagnosed. Since SLT can be as effective as eye drops in lowering eye pressure, your eye doctor may suggest the procedure if you've recently been diagnosed with open-angle glaucoma.
- You Can't Tolerate Glaucoma Medication. Although many people have no problems with prescription eye drops or oral medication to control eye pressure, some people have allergic reactions or side effects or struggle with irritated, red eyes. SLT offers a way to keep your pressure under control without medication.
- You Forget to Use the Eye Drops. Prescription eye drops are most effective when they're used consistently. If you often forget to use the eye drops, SLT offers a simple solution.
- Medication Doesn't Lower Intraocular Pressure Enough. If your eye pressure remains too high despite using your prescription eye drops as prescribed, SLT may be recommended. After SLT, you may be able to decrease the number of drops needed to control eye pressure.
- You May Be Facing Surgery. SLT might help you avoid surgery. Your eye doctor may recommend trying SLT first before considering surgery.
Wondering if selective laser trabeculoplasty is an option for you? Contact our office to schedule an appointment with the ophthalmologist.
Sources:
All About Vision: Selective Laser Trabeculoplasty (SLT), 5/12/2026
Glaucoma Research Foundation: Selective Laser Trabeculoplasty
https://glaucoma.org/treatment/laser/slt
American Academy of Ophthalmology: SLT and DSLT Laser Surgeries for Glaucoma, 6/22/2026
https://www.aao.org/eye-health/diseases/slt-dslt-laser-surgeries-glaucoma-1
PubMed: International Ophthalmology Clinics: Selective Laser Trabeculoplasty, 10/1/2024
https://pmc.ncbi.nlm.nih.gov/articles/PMC10662953/
National Glaucoma Research: Laser Procedures for Glaucoma
https://www.brightfocus.org/resource/laser-procedures-for-glaucoma/
PubMed: Ophthalmology: Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial: Six-Year Results of Primary Selective Laser Trabeculoplasty versus Eye Drops for the Treatment of Glaucoma and Ocular Hypertension, 2/2023