Selective laser trabeculoplasty (SLT) continues to move earlier in the glaucoma treatment paradigm, driven in large part by the LiGHT trial^1-3 and other studies^4-6 demonstrating durable efficacy, safety, and cost-effectiveness as a first-line therapy compared with topical medications. At the same time, the recent FDA approval of the Voyager DSLT system (Alcon), with efficacy demonstrated in the GLAUrious trial,⁷ has expanded the range of laser-based options available to clinicians.

Against this evolving backdrop, more than 20 experienced glaucoma surgeons share practical insights from their own experiences. The following tips and observations are organized into four thematic areas: patient selection and counseling, treatment pearls, postprocedure management and repeat treatment, and dispelling myths about the procedure.

Patient Selection and Counseling

Given that residency requirements currently only mandate 5 SLTs for graduation per the ACGME, and glaucoma fellowships just 1 per the AUPO—a figure far too low to master the procedure’s nuances—it is no surprise that its broader clinical utility is often overlooked.

We often frame SLT as a tool for intraocular pressure (IOP) reduction, but its most underutilized role is as a rescue therapy for the ocular surface. When we see a patient with well-controlled IOP but failing ocular surface health due to prostaglandins, we shouldn’t view SLT as a last resort before surgery. Instead, it can be viewed as a primary strategy for medication reduction. The nuance here is counseling, wherein the conversation is shifted from lowering one’s pressure to improving one’s quality of life. By successfully transitioning a patient from 2 drops to 1 (or none) by SLT, we often see a dramatic improvement in corneal staining and patient comfort within weeks. SLT success doesn’t have to be measured by mmHg but can be measured through restoration of tear film.

—Syril Dorairaj, MD, Mayo Clinic Jacksonville, Florida, and Pranav Vasu, MPH, Creighton University School of Medicine

Although SLT is often avoided in uveitic eyes due to inflammation risk, I use SLT as an IOP-lowering tool in uveitic eyes. I comanage these patients with my uveitis colleagues and only proceed with SLT with their blessing. Elevated IOP in eyes with uveitis is often multifactorial. Contributors include steroid medications, fibrinous membranes closing the angle, peripheral anterior synechiae (PAS), posterior synechiae contributing to pupillary block, and herpetic trabeculitis. SLT can be especially effective when steroid response is the primary reason for elevated IOP.

As with all SLT, it is important to perform gonioscopy prior to the procedure to confirm the angle is open with accessible TM. The examiner should particularly assess for PAS in an eye with history of uveitis.

I generally prescribe topical NSAID after SLT in primary open-angle glaucoma (POAG), but I recommend topical steroid after SLT in uveitic eyes. In the consent discussion, I explain that the patient might need an additional IOP-lowering procedure (such as trabeculotomy/goniotomy or tube implant) if the IOP remains elevated after SLT.

—Ariana Levin, MD, NYU Grossman School of Medicine

How we talk to patients about SLT matters. Most ophthalmologists would want primary SLT for themselves but are stymied when patients decline and opt for medications instead. This is because we are still learning how to talk to patients about SLT. Communicating the paradigm change is unhelpful (“Traditionally we've started with medications but now there’s a laser treatment...”). Patients hear that there is a standard of care and you are recommending deviating from it. If you believe SLT is better than medications and want your patients to derive the myriad benefits of primary SLT, consider something along the lines of, “High-quality research has shown that patients who start with SLT are less likely to get worse over time than patients who start with medications. Both are options. Here are the pros and cons of each. What questions can I answer to help you decide which is best for you?”

—Tony Realini, MD, MPH, West Virginia University Eye Institute

A very important factor in getting patients to be open to SLT is how it is presented to them. Many years ago, I had a conversation with Tom Brunner, president of the Glaucoma Research Foundation, about why more patients were not choosing SLT. He suggested that patients might be more receptive if we did not initially use the term laser but instead referred to it as light or light energy. I took that advice and began incorporating it into how I talk to patients.

When I explain SLT, I tell patients that we have 3 treatment options: medications, light energy treatment, and incisional surgery. When discussing light energy treatment, I explain that we have been using this technology for more than 20 years and that it works well for most patients. I describe how light passes through a window and how we use light to target the eye’s natural drainage system. I emphasize that the light does not cut or burn; rather, it stimulates a biologic response in the drainage tissue, allowing the pores to relax and widen so fluid can flow more easily, lowering eye pressure. I also explain that the procedure is performed sitting upright at the slit lamp, much like a routine exam, and that it takes about 5 minutes. When SLT is explained this way, patients tend to find it very approachable. The term light sounds much gentler than laser.

Later in the discussion, when I formally introduce the terms laser or SLT, some patients will notice the shift and say, “Oh, you said laser.” I explain that I intentionally started with “light energy” so they could understand the concept without preconceived notions about lasers interfering with the explanation.

—Constance Okeke, MD, MSCE, EyeCare Partners/Virginia Eye Consultants

In my practice, SLT has been a first-line treatment whenever possible for many years. I have observed that treatment-naïve eyes—those that have not had their extracellular pathways altered by pharmacologic therapy—respond best to laser trabeculoplasty.

We are not just talking about a 25% to 30% reduction in IOP. I have seen 50% to 55% reductions, with pressures dropping from 35 mmHg to 14 mmHg in treatment-naïve eyes with ocular hypertension (OHTN) or POAG that had never been treated. That has been my experience.

Even now, after publication of the LiGHT study, adoption of primary SLT has been slow. Changing established practice patterns is difficult. However, at least now we should stop seeing the infuriating question, “Primary SLT, is it ready for prime time?” posed quarterly in every throwaway journal. It needs to be replaced with “Primary SLT, the data is there, what are you waiting for?"

—Steven R. Sarkisian, Jr, MD, Oklahoma Eye Surgeons

A little over a year ago, I added DSLT into my glaucoma treatment repertoire, and it has become my preferred mode of treatment. While the end goal of both SLT and DSLT are to lower IOP, there are varied nuances between the procedures—the most important being patient selection. Patients who have heavy limbal pigment or significant corneal arcus may be challenging for the machine to locate the limbus. In addition, patients with heavily pigmented conjunctiva can experience additional discomfort during procedure. Patients with extremely deep-set orbits or narrow intrapalpebral fissures may make lid speculum placement difficult or the sclera cannot be observed 360° (a prerequisite to treatment). This small subset of patients requires traditional SLT as a means of treatment. Outside of these rare exceptions, most patients are excellent candidates for DSLT.

—Christine Funke, MD, Barnet Dulaney Perkins Eye Center

Treatment Pearls

DSLT and SLT have key differences beyond how the laser is applied. DSLT is faster (2.4 seconds), set at a higher energy level (1.8 mJ per spot vs 0.8 to 1.2 mJ), and therefore may be accompanied by pain. We do several rounds of tetracaine before DSLT, which helps. I tell patients that they may feel nothing, but it is also common to feel a “pinch” or cramp. Patients are advised to lubricate heavily after the tetracaine. I also wait a full 8 weeks to judge the DSLT response (vs 4 to 6 weeks for SLT), as I’ve noticed some delayed responses.

DSLT is now my strong preference for laser trabeculoplasty, for both patient and doctor experience reasons. However, there are a few situations where I still use manual SLT: heavy limbal pigment, dense arcus, hyperdeep anterior chambers where trabecular meshwork (TM) position may vary, or heavily pigmented angles where I desire titratability.

—Lori Provencher, MD, Vance Thompson Vision

If you are performing an SLT and the angle appears narrower than you remember, have the patient look toward the mirror. The angle will widen, making it easier to complete the SLT. 

—Marlene R. Moster, MD, South Florida Eye Health, Miami 

Once patients fail multiple drops over many years, they seem to respond less well to SLT. It’s not clear if this is because these are the tougher cases (failing many drops) or if years of drops have an impact on the success of SLT. The LiGHT trial did not show that drop therapy reduced laser efficacy, but these patients weren’t on many drops for many years.

A few other thoughts: If the angle looks a bit narrower than hoped at time of treatment, gradually increase the size and brightness of the illuminating beam—the pupil constriction opens the angle. Going quickly (once proficient) increases patient happiness—no one wants a longer procedure. Tell patients (truthfully) that this laser will help their natural drainage channel work better by stimulating it with light and a few more patients will choose this excellent treatment.

—Jonathan Myers, MD, Wills Eye Hospital

One of the most meaningful refinements I have made in my SLT technique has been the adoption of a higher-energy treatment strategy. Early in my experience, I typically initiated treatment at 0.8 mJ and titrated upward to remain just below the cavitation bubble threshold. In contrast, “high-energy” SLT intentionally produces cavitation bubbles in approximately 75% of applications, generally at energy settings in the range of 1.0 to 1.2 mJ. In most cases, I routinely treat the full 360° of TM, with the exception of eyes with pigmentary or pseudoexfoliative glaucoma, where energy and treatment extent are adjusted accordingly. Since implementing this approach, I have observed improved durability of IOP reduction with fewer retreatments, albeit with a slightly higher incidence of transient postoperative redness or ocular discomfort. 

—Shivani Kamat, MD, UT Southwestern Medical Center

One day we ran out of the standard 2.5% hydroxypropyl methylcellulose goniolens coupling agent. In a pinch, I used an over-the-counter lubricating gel containing HPMC 0.3%. It worked just as well in terms of lens retention and optical clarity. Importantly, being less viscous, the lens spun much more easily, it was easier to clean the patient’s eye (and face) afterward, and the post-treatment visual blurring from the thick coupling agent was much improved, leading to faster visual recovery. I never went back.

—Tony Realini, MD 

Postprocedure Management and Repeat Treatment

After SLT, I don’t use any steroids or NSAIDS because I want some mild inflammatory reaction. I only use steroids if the patient has anterior cell, significant light sensitivity, or rarely corneal edema. 

—Sahar Bedrood MD, PhD, Advanced Vision Care 

One thing many people may not realize is that when you perform a postoperative check about 2 weeks after the procedure, if there is an early effect and the patient is at their target pressure or better, there is greater than a 98% chance that the same result will be seen at 3 months. In these cases, you may be able to eliminate a follow-up visit. You do not necessarily need to see the patient again a month later to confirm the full effect of the procedure.

This is something we published a long time ago,⁸ but it has not received much attention. At a time when we are trying to maximize clinic volume and carefully allocate appointment slots to patients who most need them, this information can be helpful.

—Douglas J. Rhee, MD, Case Western Reserve University School of Medicine

The old adage that SLT can only be repeated if the initial treatment was successful has been discredited. Several recent studies^9-11 have shown that regardless of initial response patients can respond well to a repeat SLT. As such, I now treat patients a second time regardless of initial response.

—Jacob Brubaker, MD, Sacramento Eye Consultants

The repeatability of SLT has long been a subject of debate. Evidence was previously limited to small, retrospective case series showing varying success rates of repeat vs initial SLT. The landmark LiGHT trial not only demonstrated the effectiveness of SLT as a first-line therapy for treatment-naïve patients with OHTN and OAG but also provided high-level evidence regarding the repeatability of SLT. In a post hoc analysis of 115 medication-naïve eyes from the SLT arm of the study, 67% of eyes that underwent repeat SLT maintained their target IOP without additional treatment at 18 months. Importantly, most of these eyes (68%) had OHTN or mild disease. A longer duration of effect was observed after repeat vs initial SLT, suggesting a potential additive IOP-lowering effect.¹¹

I now routinely offer a second SLT to my medication-naïve patients with OHTN and mild OAG whose IOPs are above target after initial SLT to keep them off topical medications. The benefit of a third (or more) SLT retreatment still requires additional study. I eagerly anticipate the results from the ongoing COAST trial, which explores the optimal energy settings and treatment intervals for repeat SLT, to further guide us in practicing evidence-based glaucoma.

—Kateki Vinod, MD, New York Eye and Ear Infirmary of Mount Sinai 

One of the misconceptions I inherited from the collective experience with argon laser trabeculoplasty (ALT) is that SLT should only be repeated with caution—maybe once or twice. We now know that SLT can safely be repeated in the long term as many as 4 times, according to the LiGHT trial papers published so far. Additionally, I used to think that if someone did not respond to SLT the first time, we should move onto something else. LiGHT changed my views completely. For those initial “nonresponders,” it is most likely that they were underdosed, and a repeat SLT early (in the first few months) may get the response we desire. 

One surprising observation that I have made is that there seems to be a consensual response to SLT in the fellow eye. I have not reviewed my outcomes to understand the significance of this observed phenomenon, but casual discussion with colleagues has confirmed that they have also made this observation. As to the question, “Do you still treat the fellow eye?”—all of us would. Perhaps this is the next research question to tackle.

—Lauren S. Blieden, MD, Baylor College of Medicine

Although the SALT trial suggested that short-term ketorolac 0.5% improved IOP reduction at 12 weeks compared with placebo,¹² more recent data indicate that topical NSAIDs may blunt SLT efficacy.¹³ Furthermore, a 2025 randomized controlled trial demonstrated higher SLT success rates with postprocedure prednisolone acetate 1% four times daily for 7 days compared with ketorolac.¹⁴

—Mary Qiu, MD, and Samantha Goldburg, MD, Cleveland Clinic

Dispelling Myths About the Procedure

Perhaps the most baffling aspect of SLT adoption is the striking inconsistency between physician preference and real-world practice. In discussions with ophthalmologists and optometrists, nearly all say they would choose SLT first if it were their own eye. However, when asked how often their patients receive SLT as initial therapy, most report rates around 10%. This gap raises an important question: why does our personal conviction so rarely translate into patient care?

—John Berdahl, MD, Vance Thompson Vision 

SLT can be misunderstood, leading to persistent myths that can influence both physician adoption and patient counseling. Contrary to the belief that SLT “burns” or damages the TM, SLT employs low-energy, short-pulse laser delivery that selectively targets pigmented trabecular cells without causing coagulative damage or structural scarring, thereby preserving trabecular architecture. SLT is also not reserved solely for patients who have failed topical therapy; substantial evidence supports its use as a first-line treatment for POAG and OHTN, with IOP-lowering efficacy comparable to prostaglandin analogs and without the burden of long-term medication adherence.

Another common misconception is that SLT works immediately. IOP reduction is typically gradual, with maximal effect occurring approximately 6 weeks after treatment. Thus, early postlaser measurements may underestimate its true efficacy.

—Shivani Kamat, MD

Same-day bilateral SLT is cost effective at the practice level. When both eyes are treated in the same session, the fee for the second eye is reduced by 50%. However, consider the staffing and time costs associated with the following: scheduling time for the second-eye treatment visit; front desk check-in and check-out time on day of second eye treatment; technician time to work the patient up and consent the patient for second eye treatment; physician time to address any issues that arose after the first treatment; physician time to position patient at the SLT and align/focus the laser; and the patient costs (time and travel) for a second visit. It’s cost effective to take the extra 3 minutes and treat the second eye on the same day.  GP

—Tony Realini, MD 

References

1. Gazzard G, Konstantakopoulou E, Garway-Heath D, 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. doi:10.1016/S0140-6736(18)32213-X

2. Gazzard G, Konstantakopoulou E, Garway-Heath D, 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):139-151. doi:10.1016/j.ophtha.2022.09.009

3. Montesano G, Crabb DP, Garway-Heath DF, et al. Six-year rate of visual field progression in the laser in glaucoma and ocular hypertension trial. Ophthalmology. 2026;133(2):169-177. doi:10.1016/j.ophtha.2025.09.023

4. The Glaucoma Laser Trial (GLT). 2. Results of argon laser trabeculoplasty versus topical medicines. The Glaucoma Laser Trial Research Group. Ophthalmology. 1990;97(11):1403-1413.

5. Takusagawa HL, Hoguet A, Sit AJ, et al. Selective laser trabeculoplasty for the treatment of glaucoma: a report by the American Academy of Ophthalmology. Ophthalmology. 2024;131(1):37-47. doi:10.1016/j.ophtha.2023.07.029

6. Realini T, Gazzard G. Selective laser trabeculoplasty and the evolving glaucoma paradigm. Ophthalmol Glaucoma. 2025;8(5S):S38-S44. doi:10.1016/j.ogla.2025.06.010

7. Congdon N, Azuara-Blanco A, Solberg Y, et al. Direct selective laser trabeculoplasty in open angle glaucoma study design: a multicentre, randomised, controlled, investigator-masked trial (GLAUrious). Br J Ophthalmol. 2023;107(1):62-65. doi:10.1136/bjophthalmol-2021-319379

8. Johnson PB, Katz LJ, Rhee DJ. Selective laser trabeculoplasty: predictive value of early intraocular pressure measurements for success at 3 months. Br J Ophthalmol. 2006;90(6):741-743. doi:10.1136/bjo.2005.086363

9. Wang P, Akkach S, Andrew NH, Wells AP. Selective laser trabeculoplasty: outcomes of multiple repeat treatments. Ophthalmol Glaucoma. 2021;4(5):482-489. doi:10.1016/j.ogla.2020.12.013.

10. Yang Y, Xu K, Chen Z, et al; LiGHT China Trial Study Group. Responsiveness to selective laser trabeculoplasty in open-angle glaucoma and ocular hypertension. JAMA Ophthalmol. 2024;142(10):918-924. doi:10.1001/jamaophthalmol.2024.3133.

11. Garg A, Vickerstaff V, Nathwani N, et al. Efficacy of repeat selective laser trabeculoplasty in medication-naive open-angle glaucoma and ocular hypertension during the LiGHT trial. Ophthalmology. 2020;127(4):467-476. doi:10.1016/j.ophtha.2019.10.023

12. Groth SL, Albeiruti E, Nunez M, et al. SALT Trial: Steroids after laser trabeculoplasty: impact of short-term anti-inflammatory treatment on selective laser trabeculoplasty efficacy. Ophthalmology. 2019;126(11):1511-1516. doi:10.1016/j.ophtha.2019.05.032

13. Dahlgren T, Ayala M, Zetterberg M. The impact of topical NSAID treatment on selective laser trabeculoplasty efficacy. Acta Ophthalmol. 2023;101(3):266-276. doi:10.1111/aos.15276

14. Miranda JF, Maestrini HA, Barbosa CCP, et al. Effect of anti-inflammatory regimen on selective laser trabeculoplasty outcomes: a randomized controlled trial. J Glaucoma. 2025;34(6):421-427. doi:10.1097/IJG.0000000000002555