Selective Laser Trabeculoplasty (SLT) is a significant treatment method that has recently attracted particular attention in the treatment of glaucoma. Glaucoma is a serious, multifactorial disease characterized by elevated intraocular pressure (IOP), often higher than normal, progressing insidiously and leading to damage to the optic nerve and, if left uncontrolled, permanent vision loss.

Often asymptomatic, it can be diagnosed during routine examinations by measuring IOP and examining the fundus of the eye. Lowering IOP is one of the most important controllable factors in glaucoma treatment. While first-line treatment for glaucoma usually begins with eye drops, depending on the patient’s eye condition, the stage of the eye pressure (the level of structural and functional damage), patient compliance with eye drop use, potential drug side effects, and the presence of comorbidities, some patients may require laser treatment or surgery. Among laser treatments, selective laser trabeculoplasty (SLT) is an effective, safe, and non-surgical first-line treatment that can be used as an alternative to eye drops or as an additional supportive treatment to reduce the number of drops. 

Offering a chance for long-term drug-free follow-up in approximately three-quarters of patients, with a low risk of side effects, repeatability, and cost-effectiveness, SLT has recently become a preferred treatment option in modern glaucoma management. Furthermore, it does not preclude surgical intervention if necessary later. It is particularly preferable in pregnant women due to its low risk of side effects and safety. SLT is also an effective and safe treatment option to consider in the management of patients with ocular hypertension and primary open-angle glaucoma who have difficulty with medication, frequently forget to take their medication, or for whom we want to reduce the cumulative eye drop burden over the long term. However, not every patient is suitable for SLT treatment. SLT (Supplementary Leukemia and Thrombosis) is particularly recommended as a first-line treatment for conditions such as primary open-angle glaucoma, pseudoexfoliative glaucoma, pigmentary glaucoma, and high-risk ocular hypertension, where the outflow angle of the aqueous humor of the eye is open. Topical eye drops still maintain their place as first-line treatment in patients with relatively low baseline intraocular pressure, who can consistently and consistently use eye drops, and who have good compliance and consistency. However, considering the difficulties associated with poor compliance and consistency with eye drops, the challenges of using multiple bottles of drops, and the local and/or systemic side effects that may occur in some patients, SLT treatment has recently become more preferred.

SLT (Selective Laparoscopic Treatment) is a short procedure that can be performed in an outpatient setting and does not require an operating room. SLT has a good safety profile, minimal tissue damage, and is repeatable when its effect diminishes or wears off. SLT is called “selective laser” because the short-duration, low-energy laser light affects only the pigmented cells in the trabecular meshwork, without damaging surrounding tissues . This effect on the outflow channels stimulates cellular and biochemical responses, stretching the trabecular meshwork and opening the spaces between them, increasing the outflow of aqueous humor (intraocular fluid) and thus lowering intraocular pressure (eye pressure), hence the name “Trabeculoplasty.” It contributes to halting the progression of glaucoma damage. Its effectiveness may decrease over time. If intraocular pressure rises again over time, SLT can be repeated. Although it can be repeated as needed, the effectiveness of repeated applications may decrease compared to the initial application.

A transient intraocular pressure peak (increase) may occur in the early period after SLT, but this peak can usually be prevented with antiglaucoma medications administered before and after the procedure. Intraocular bleeding may occur in some patients using blood thinners. The effects of SLT do not last a lifetime, therefore it is important to continue regular patient monitoring (follow-up and treatment).

According to the latest edition of the European Glaucoma Society (EGS) guidelines, published September 8, 2025, prostaglandin analogs and SLTs, frequently recommended as first-line (initial) treatment for glaucoma, reduce intraocular pressure by approximately 30-35%. The Laser in Glaucoma and Ocular Hypertension (LiGHT) study is a multicenter randomized clinical trial comparing selective laser trabeculoplasty (SLT) and intraocular pressure (IOP)-lowering eye drops as first-line treatment in patients with newly diagnosed ocular hypertension (OHT) and open-angle glaucoma (AAG). The main outcome of the study was reported after 3 years, showing that SLT was more cost-effective than eye drops as first-line treatment. Furthermore, 74.2% of patients who received initial treatment with SLT did not use eye drops after 3 years and experienced a reduction in the rate of glaucoma surgery. (1) The follow-up of the study was later extended to 6 years , and these results were confirmed. (2) SLT has been evaluated as a first-line treatment for newly diagnosed OHT and AAG eyes, and is considered more effective than eye drops in preserving visual field. (3) Many factors influence these results. Which patient is suitable for this treatment should be evaluated “personally” on a case-by-case basis, according to each patient and even the condition of each eye.

Has SLT replaced glaucoma drops?

Glaucoma treatment is “individualized”; there is no standard approach for every patient. Antiglaucomatous topical eye drops are an effective and safe first-line treatment method for patients with relatively low initial intraocular pressure, consistent use of drops, good compliance, and who are systemically “suitable”. SLT (Supplemental Leukemia and Thrombosis) should be prioritized, especially in newly diagnosed open-angle glaucoma patients with high intraocular pressure, those with poor adherence to eye drops, those using multiple drops, and those with a potential for interruption due to side effects or forgetting to take drops. Eye drops and SLT treatment can be used alone, together, or sequentially, depending on the patient’s needs, to adequately lower intraocular pressure. The effect of SLT lasts for a certain period and can be repeated when its effect diminishes. Regular post-procedure follow-up appointments are necessary for monitoring this effect. The treatment needed to keep glaucoma under control varies from patient to patient. Individualized treatment options are tailored and planned according to the patient’s needs at each follow-up visit. It is important to remember that glaucoma treatment and follow-up are lifelong.

In summary, SLT is a safe and effective treatment option for lowering intraocular pressure in patients with ocular hypertension and open-angle glaucoma who have high intraocular pressure. It can be used as a first-line (initial) treatment for early-stage glaucoma during pregnancy, or as an additional supportive treatment when glaucoma drops are insufficient. Its repeatability, efficacy, and good safety profile are the reasons for its preference.

*The page content is for informational purposes only. Outcomes may vary from person to person in any surgical procedure. For diagnosis and treatment, please consult your doctor.

Sources

  1. Gazzard G, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial. Lancet. 2019;393 (10180):1505—1516.
  2. Gazzard G, et al. 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. Ophthalmology. 2023;130(2):139—35

         3. Montesano G, et al. Six-Year Rate of Visual Field Progression in the Laser in Glaucoma and Ocular Hypertension Trial. Ophthalmology. 2025 Oct 1:S0161-6420(25)00610-4.  Online ahead of print.

  1. Kumbhani R, et al. Selective Laser Trabeculoplasty Outcomes in Phakic and Pseudophakic Patients: A Meta-Analysis. Curr Ophthalmol. 2025;36(3):242-251.
  2. KonstantakopoulouE, et al ; LiGHT Trial Study Group. Selective Laser Trabeculoplasty After Medical Treatment for Glaucoma or Ocular Hypertension. JAMA Ophthalmol. 2025 Apr 1;143(4):295-302. 
  3. Chen KY, et al. What is the long-term efficacy and safety of selective laser trabeculoplasty in the management of primary open-angle glaucoma? A systematic review and meta-analysis. Photodiagnosis Photodyn Ther. 2025 Aug 7;56:104743. Online ahead of print.