Two-Year Clinical Results After Selective Laser Trabeculoplasty for Normal Tension Glaucoma

The Impact of Baseline Intraocular Pressure on Initial Treatment Response in the LiGHT Trial: Selective Laser Trabeculoplasty versus Medication

PURPOSE

The Laser in Glaucoma and Ocular Hypertension Trial demonstrated the efficacy and safety of selective laser trabeculoplasty (SLT) compared with topical hypotensive medication as first-line therapy for ocular hypertension and open-angle glaucoma. This substudy explored the impact of pretreatment (baseline) intraocular pressure (IOP) on treatment response.

DESIGN

Post hoc analysis of randomized control trial data.

PARTICIPANTS

A total of 1146 eyes from 662 patients were included in this analysis: 559 eyes in the SLT group and 587 in the medication group.

METHODS

Intraocular pressure reduction at 8 weeks after treatment with either SLT or prostaglandin analog (PGA) eye drops was assessed at different levels of baseline IOP, and the groups were compared. Differences in absolute and percentage IOP lowering between SLT and PGA groups were tested with a linear mixed-effects model. Differences in the probability of achieving ≥ 20% IOP lowering between SLT and PGA groups, at different levels of baseline IOP, were estimated using a logistic mixed-effects model.

MAIN OUTCOME MEASURE

Intraocular pressure-lowering response to SLT versus PGA eye drops.

RESULTS

Mean IOP was not significantly different between the groups at baseline or 8 weeks after treatment initiation. Both treatments showed greater IOP lowering at higher baseline IOP and less IOP lowering at lower baseline IOP. Selective laser trabeculoplasty tended to achieve more IOP lowering than PGA drops at higher baseline IOP. Prostaglandin analog drops performed better at lower baseline IOP, and the difference compared with SLT, in terms of percentage IOP reduction, was significant at baseline IOP of ≤ 17 mmHg. A significant difference was found in the relationship between baseline IOP and probability of ≥ 20% IOP lowering between the two treatments (P = 0.01), with SLT being more successful than PGA at baseline IOP of more than 22.5 mmHg.

CONCLUSIONS

We confirm previous reports of greater IOP lowering with higher baseline IOP for both SLT and PGA drops. In treatment-naïve eyes, at higher baseline IOP, SLT was more successful at achieving ≥ 20% IOP lowering than PGA drops. At lower baseline IOP, a statistically greater percentage, but not absolute, IOP lowering was seen with PGA drops compared with SLT, although the clinical significance of this is uncertain.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Efficacy and safety of first-line or second-line selective laser trabeculoplasty for normal-tension glaucoma: a multicentre cohort study

BACKGROUND/AIMS

This study aimed to investigate and compare the efficacy and safety of first-line and second-line selective laser trabeculoplasty (SLT) in Japanese patients with normal-tension glaucoma (NTG).

METHODS

100 patients with NTG were enrolled in this study. Patients were treated with SLT as a first-line or second-line treatment for NTG. Main outcome measures were intraocular pressure (IOP) reduction rate, outflow pressure improvement rate (ΔOP), success rate at 1 year and complications. Success was defined as ΔOP≥20% (criterion A) or an IOP reduction ≥20% (criterion B) without additional IOP-lowering eye-drops, repeat SLT or additional glaucoma surgeries. The incidence of transient IOP spike (>5 mm Hg from the pretreatment IOP), conjunctival hyperaemia, inflammation in the anterior chamber and visual impairment due to SLT were assessed.

RESULTS

A total of 99 patients (99 eyes) were initially enrolled in this study, including 74 eyes assigned to the first-line SLT group and 25 eyes to the second-line SLT group. The mean IOP of 16.3±2.1 mm Hg before SLT decreased by 17.1%±9.5% to 13.4±1.9 mm Hg at 12 months after SLT in the first-line group (p<0.001), and the mean IOP of 15.4±1.5 mm Hg before SLT decreased by 12.7%±9.7% to 13.2±2.0 mm Hg at 12 months after SLT (p=0.005) in the second-line group. Both groups showed significant reductions in IOP. Higher pre-SLT IOP and thinner central corneal thickness were associated with greater IOP reduction. The success rate at 1 year was higher in the first-line compared with the second-line group, with lower pretreatment IOP and the use of IOP-lowering medication before SLT being associated with treatment failure. Most post-treatment complications were minor and transient.

CONCLUSIONS

SLT may be an effective and safe treatment option for NTG, as either a first-line or second-line treatment.

TRIAL REGISTRATION NUMBER

The study was registered in the UMIN-CTR (UMIN Test ID: UMIN R000044059).

Selective laser trabeculoplasty: An updated narrative review

Selective laser trabeculoplasty (SLT) has experienced a resurgence in interest, primarily driven by promising findings from the Laser in Glaucoma and Ocular Hypertension Trial. By offering SLT as an initial drug-free treatment option, we may be able to thwart issues such as adherence and persistence that plague our current medical management protocols. In this comprehensive narrative review, we delve into the current body of literature that explores the utility of SLT across a wide spectrum of scenarios and glaucoma subtypes. We present evidence that provides valuable insight into the efficacy and benefits of SLT, positioning it as a viable option in the management of glaucoma. Careful consideration of the associated risks and challenges is also necessary for successful adoption into clinical practice. Despite the ample evidence supporting SLT's efficacy, some questions remain regarding its long-term effects and the potential need for retreatment. This review aims to shed light on these aspects to guide clinicians in making informed decisions and tailoring treatment plans to individual patient needs. This review also provides the readers with a bird's eye view of the potential impact of SLT and adds clarity to the various therapeutic protocols that one can follow to ensure optimal clinical outcomes for our patients.

Selective Laser Trabeculoplasty

Selective laser trabeculoplasty (SLT) is a common ophthalmic procedure used to lower intraocular pressure. The mechanism of SLT action remains controversial but may involve the upregulation of protein expressions in the trabecular meshwork that increases outflow facility. Several prospective trials have demonstrated the safety and efficacy of SLT as both adjunctive and primary glaucoma therapy, and the utilization of SLT in stable, medically-controlled glaucoma patients may decrease medication burden and potentially improve the patients’ quality of life.

Selective laser trabeculoplasty is safe and effective in patients previously treated with prostaglandin analogs: An evidence-based review

PURPOSE

Prostaglandin analogs (PGAs) are first-line treatments for ocular hypertension (OHT) and open-angle glaucoma (OAG). However, frequent side effects and high costs hinder patient's compliance resulting in disease progression. Evidence suggests selective laser trabeculoplasty (SLT) may be considered a first-line treatment for OHT and OAG due to its safety profile, minor side effects, and reduced costs. Considering that PGAs and SLT share action mechanisms, it is hypothesized that previous PGA therapy may affect subsequent SLT efficacy. Therefore, we analyzed if PGAs reduce SLT efficacy.

METHODS

An evidence-based review was performed to assess the safety and efficacy of SLT in patients previously treated with PGAs. For this purpose, we performed an extensive literature search using the National Library of Medicine's PubMed and Google Scholar database for all English language articles published until May 2021.

RESULTS

There is evidence of non-superiority of PGAs therapy versus SLT for OHT and OAG. A multicenter, randomized, observer-masked clinical trial (RCT) of untreated OHT and OAG patients concluded that SLT should be offered as the first-line treatment for these patients. This study was supported by a meta-analysis of RCTs, comparing SLT efficacy versus antiglaucoma drugs only, with the advantage of an SLT lower rate of adverse effects.

CONCLUSIONS

Cost-effectiveness, patient compliance, and antiglaucoma drugs' side effects, including higher surgical failure, favor consideration of SLT as first-line therapy for OAG and OHT. Furthermore, SLT efficacy does not seem to be affected by prior PGA administration; however, larger cohort, comparative, multicenter RCTs are necessary to answer this question.

Energy Dose-Response in Selective Laser Trabeculoplasty: A Review

PRCIS

A literature review of selective laser trabeculoplasty (SLT) energy dose-response found no definitive relationship between intraocular pressure (IOP) reduction with respect to total or pulse energy, race, pigmentation, or application pattern.

PURPOSE

SLT is a safe and effective treatment for lowering IOP. Although evidence is mounting for the advantage of its use as a first-line treatment for IOP reduction, the SLT procedures in use vary widely. The purpose of this literature review was to investigate whether there were any relationships between SLT energy and efficacy for lowering IOP in the published literature.

METHODS

A literature review was undertaken that included studies in which energy levels required for successful SLT treatment were investigated: in general, with respect to angle pigmentation, race or ethnicity, and treatment arc extent.

RESULTS

There was no indication that higher (or lower) energy used in the treatment leads to greater (or less) IOP reduction. Similar results were obtained regarding the level of trabecular meshwork pigmentation. Race was not found to be associated with altered dose response in SLT. There were indications that treating the full 360 degrees, as opposed to smaller arcs, could be beneficial for more IOP reduction. IOP reduction from SLT was found to be similar to that provided by topical medications.

CONCLUSIONS

The optimal energy level of SLT needed for IOP reduction has not yet been definitively established, with all reported pulse energies resulting in similar IOP reduction. Furthermore, similar lack of conclusive findings exists regarding optimal SLT energy dosage for use in different races and degrees of trabecular meshwork pigmentation. This parameter and each of the abovementioned factors requires further research.

A Review of Selective Laser Trabeculoplasty: "The Hype Is Real"

Presently, there is no efficacious treatment for glaucomatous optic neuropathy; the current treatment is focused on lowering intraocular pressure (IOP). Studies have demonstrated the safety and efficacy of selective laser trabeculoplasty (SLT) in reducing the IOP in eyes with open-angle (OAG) glaucoma or ocular hypertension (OH). Moreover, the European Glaucoma Society has instated SLT as the first-line or adjunctive treatment in OAG or OH, reiterating its clinical significance. In this review, we outline the old and the new roles of SLT, with an emphasis on clinical practice, and look further into its renewed appeal and future developments.

Intraocular Pressure-Lowering Efficacy of a Sustained-Release Bimatoprost Implant in Dog Eyes Pretreated with Selective Laser Trabeculoplasty

Purpose: To assess the intraocular pressure (IOP)-lowering effect of a biodegradable bimatoprost implant following selective laser trabeculoplasty (SLT) in a canine model. Methods: Unilateral SLT was performed in 11 normotensive, treatment-naive beagle dogs. IOP was measured at baseline (pre-SLT) and weekly post-SLT (≤10 weeks). After IOP returned to baseline or at 10 weeks (whichever occurred first), a sustained-release bimatoprost implant was administered bilaterally in the anterior chamber of each animal. IOP was measured weekly for 4 weeks and then every 2 weeks up to week 42. Results: The main outcomes included the IOP change (%) from baseline, calculated in both eyes in the overall population, SLT responder subgroup (defined by peak IOP reduction from baseline ≥3 mmHg or ≥15% for >1 week post-SLT), and SLT nonresponder subgroup (defined by peak IOP reduction from baseline <3 mmHg or <15%). The bimatoprost implant lowered IOP similarly in both the SLT-treated and fellow SLT-naive eyes. Following bimatoprost implant administration, the mean (standard deviation [SD]) peak IOP reduction from baseline was 34.4% (8.5%) in SLT-treated eyes and 35.7% (5.9%) in fellow SLT-naive eyes. The bimatoprost implant lowered IOP comparably (P > 0.17) in eyes that responded to SLT (mean [SD] peak IOP reduction, 34.6% [10.7%]; n = 6) and those that did not (mean [SD] peak IOP reduction, 34.1% [6.1%]; n = 5). Conclusion: The bimatoprost implant effectively lowered IOP in eyes pretreated with SLT, regardless of response to SLT. The current data suggest that eyes previously treated with SLT can still benefit from the intracameral bimatoprost implant.

Selective laser trabeculoplasty: A review

Glaucoma is the second most prevalent cause of blindness worldwide, and the only effective management is the lowering of intraocular pressure (IOP). Selective laser trabeculoplasty (SLT) has become an essential part of glaucoma management since its commercial release in 2001. It has been an improvement from the previous argon laser trabeculoplasty (ALT), by using 1% of the laser energy, reducing the amount of anterior segment inflammation and minimising the degree of mechanical injury to the trabecular meshwork. There is now a large volume of work that demonstrates SLT is equally effective as ALT and topical medication in lowering IOP. It is simple to perform, with a well described side-effect profile, and is long-lasting and repeatable. This review will summarise the current literature on SLT for each of these topics.

Outcome After Selective Laser Trabeculoplasty for Glaucoma Treatment in a Thai Population

Purpose

The study aimed to evaluate the efficacy and predictive factors of success after selective laser trabeculoplasty (SLT) for treating various types of open-angle glaucoma in a Thai population.

Design

The study employed a retrospective cohort design.

Materials and Methods

The study retrospectively recruited Thai subjects diagnosed with open-angle glaucoma receiving first time selective laser trabeculoplasty. Primary open-angle glaucoma (POAG), ocular hypertension (OHT) and other types of open-angle glaucoma were included. Reduced intraocular pressure (IOP) of 20% or decreased number of antiglaucoma drugs usage after SLT was defined as success. Various parameters were analyzed for association with SLT success.

Results

Ninety-six eyes were recruited in the study. Mean pre- and postSLT IOP were 19.31±3.59 and 15.04±3.13 mmHg, respectively. IOP decreased significantly in all follow-up visits (p<0.001). Overall, 59.4% met the treatment endpoint. More than 10% postSLT IOP elevation at 1 hour was the only covariate positively associated with SLT success in both univariate (odds ratio (OR) = 1.042, p = 0.037) and multivariate analyses (OR = 1.040, p = 0.046). Underlying hypertension and preSLT IOP were negatively associated with SLT success in both univariate (OR = 0.970, p = 0.026, OR = 0.955, p < 0.001) and multivariate analysis (OR = 0.970, p = 0.026, OR = 0.991, p < 0.001).

Conclusion

IOP significantly decreased as well as the number of antiglaucoma drugs needed after SLT. More than 10% postSLT IOP elevation at 1 hour was a positive predictor whereas systemic hypertension and preSLT IOP were negative predictors of SLT success.

Normal tension glaucoma in Asia: Epidemiology, pathogenesis, diagnosis, and management

Normal tension glaucoma (NTG) has similar optic neuropathy as primary open-angle glaucoma (POAG), but intraocular pressure (IOP) is within the normal range. Compared with high-pressure POAG, the development of NTG is possibly a consequence of a complex interaction of several ocular and systemic factors. Recent data have shown higher translaminar pressure gradient due to impaired cerebrospinal fluid dynamics may account for the pathogenic mechanism. Insufficient blood supply and vascular dysregulation may also be the cause of the disease. In clinical evaluation, NTG is a diagnosis by excluding other nonglaucomatous optic neuropathies. NTG is characterized by larger and deeper optic-disc cupping, more central visual field defects and a higher incidence of disc hemorrhage compared with POAG. In clinical practice, controlling IOP as low as possible (with medication, laser trabeculoplasty, or surgery) is the key to manage NTG patients. In addition to IOP reduction, the control of systemic risk factors or improving ocular perfusion may be beneficial therapies. NTG is more prevalent in Asia than in the Western countries. Due to increasing old population and underdiagnoses in the clinical settings, NTG became a great challenge for ophthalmologist in Asia. Therefore, the aim of this article is to focus on the epidemiology, to update pathogenesis, diagnosis, and management for NTG.

Management of the glaucoma patient progressing at low normal intraocular pressure

PURPOSE OF REVIEW

Patients with glaucoma with disease progression despite low or normal intraocular pressure (IOP) present special challenges to the treating clinician. Treatment goals may depend on whether patients have apparent low IOP with concurrent treatment or have low IOP at baseline without treatment. We review the diagnostic and therapeutic approaches to these patients.

RECENT FINDINGS

Apparent progression at low IOP should start with confirmation of IOP, made easier by devices enabling patient home self-tonometry. Suspected visual field progression should be confirmed by repeat testing prior to advancement of therapy. Trabeculectomy remains the most effective surgical method of achieving long-term success, particularly when there is a low starting IOP. Drainage tube implantation or the use of novel micro-incisional non-bleb-forming procedures are less likely to be successful in achieving low IOP goals.

SUMMARY

Diagnostic testing is important in confirming progressive glaucomatous disease at low IOP levels. The most effective way of slowing the progression of glaucoma in a patient with low IOP is to lower the IOP further, sometimes to single digit levels, which is most often achievable with trabeculectomy.

Primary Selective Laser Trabeculoplasty for Open-Angle Glaucoma and Ocular Hypertension: Clinical Outcomes, Predictors of Success, and Safety from the Laser in Glaucoma and Ocular Hypertension Trial

PURPOSE

To report clinical efficacy, predictors of success, and safety of primary selective laser trabeculoplasty (SLT) used in treatment-naive patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).

DESIGN

Post hoc analysis of a multicenter, prospective, randomized, controlled trial.

PARTICIPANTS

Treatment-naive patients with OAG or OHT.

METHODS

Patients randomized to SLT or topical medication and treated to predefined target intraocular pressures (IOPs) requiring ≥20% IOP reduction from baseline for all disease severity levels.

OUTCOME MEASURES

Initial (early) absolute IOP-lowering at 2 months. Achievement of drop-free disease-control: meeting target IOP without disease progression or need for additional topical medication over 36 months after SLT. Predictors of early absolute IOP-lowering and drop-free disease-control after single initial SLT. Frequency of laser-related complications.

RESULTS

A total of 611 eyes (195 OHT and 416 OAG) of 355 patients received SLT, and 622 eyes (185 OHT and 437 OAG) of 362 patients received topical medication at baseline. Early absolute IOP-lowering after SLT was no different between OHT and OAG eyes (adjusted mean difference = -0.05 mmHg; 95% confidence interval [CI], -0.6 to 0.5 mmHg; P = 0.85). No difference was noted in early absolute IOP-lowering between topical medication and primary SLT (adjusted mean difference = -0.1 mmHg; 95% CI, -0.6 to 0.4 mmHg; P = 0.67). Early absolute IOP-lowering with primary SLT was positively associated with baseline IOP (coefficient 0.58; 95% CI, 0.53-0.63; P < 0.001) and negatively with female gender (coefficient -0.63; 95% CI, -1.23 to -0.02; P = 0.04). At 36 months, 536 eyes (87.7% of 611 eyes) of 314 patients (88.5% of 355 patients) were available for analysis. Some 74.6% of eyes (400 eyes) treated with primary SLT achieved drop-free disease-control at 36 months; 58.2% (312 eyes) after single SLT. Total SLT power and 2-month IOP were predictors of drop-free disease-control at 36 months after single SLT. Six eyes of 6 patients experienced immediate post-laser IOP spike (>5 mmHg from pretreatment IOP) with 1 eye requiring treatment.

CONCLUSIONS

Primary SLT achieved comparable early absolute IOP-lowering in OHT versus OAG eyes. Drop-free disease-control was achieved in approximately 75% eyes at 36 months after 1 or 2 SLTs, the majority of these after single SLT. These analyses are exploratory but support primary SLT to be effective and safe in treatment-naive OAG and OHT eyes.

Lasers in glaucoma

While lasers have been used for many years for the treatment of glaucoma, proper indications and use of the procedures need to be considered before their application. This review summarizes the important laser procedures in Glaucoma.

Selective laser trabeculoplasty: past, present, and future

Over the past two decades, selective laser trabeculoplasty (SLT) has increasingly become an established laser treatment used to lower intraocular pressure in open-angle glaucoma and ocular hypertensive patients. In this review we trace the origins of SLT from previous argon laser trabeculoplasty and review the current role it has in clinical practice. We outline future directions of SLT research and introduce emerging technologies that are further developing this intervention in the treatment paradigm of glaucoma.

Randomized Prospective Study of the Use of Anti-Inflammatory Drops After Selective Laser Trabeculoplasty

PURPOSE

Evaluating the use of Indomethacin, Dexamethasone, and no anti-inflammatory treatment immediately after selective laser trabeculoplasty (SLT).

MATERIALS AND METHODS

Prospective randomized clinical trial of 132 eyes. Both eyes of the patient underwent SLT. One of the eyes was treated with Indomethacin 0.1% or Dexamethasone 0.1% 3 times daily for 1 week; the other eye did not receive any anti-inflammatory treatment. Intraocular pressure (IOP) and inflammatory parameters were recorded at 1 hour, 1 week, 1, 3, and 6 months.

RESULTS

Cells in the anterior chamber were present in 57% to 71% of the patients after 1 hour. About 16% to 37% of the patients reported pain/discomfort after 1 hour. Redness was present before SLT in 29% to 34% of the patients, probably due to antiglaucoma medication. After 1 hour, the amount of redness recorded raised to 32% to 42%, but the amount of patients with redness returned to pretreatment levels after 1 week. An IOP peak of >5 mm Hg above baseline IOP 1 hour after laser was present in 3% to 9% of the patients. IOP lowered 11% to 21% compared with IOP at baseline. The number of medications needed changed from 1.45 to 1.49 before, to 0.23 to 0.45 six months after SLT.No differential effects based on the kind of anti-inflammatory treatment or no treatment were found for any of the parameters.

CONCLUSIONS

SLT induces little inflammation: anti-inflammatory drops do not make a significant difference in pain, redness, cells in anterior chamber, or peak IOP following SLT.The IOP-lowering effect of the SLT is not influenced by the use of Indomethacin or Dexamethasone.

A Review of Selective Laser Trabeculoplasty: Recent Findings and Current Perspectives

Selective laser trabeculoplasty (SLT) has been widely used in the clinical management of glaucoma, both as primary and adjunctive treatment. As new evidence continues to arise, we review the current literature in terms of indications and efficacy, surgical technique, postoperative care, repeatability, and complications of this therapy. SLT has been shown to be effective in various glaucomas, including primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), steroid-induced glaucoma, pseudoexfoliation glaucoma (PXFG), and primary angle-closure glaucoma (PACG), as well as other glaucoma subtypes. Relatively high preoperative intraocular pressure (IOP) may predict surgical success, while other parameters that have been studied do not seem to affect the outcome. Different techniques for performing the procedure have recently been explored, revealing that minor modifications may lead to a more favorable or safer clinical outcome. The utilization of postoperative medications remains controversial based on the current evidence. A short-term IOP increase may complicate SLT and can also persist in certain cases such as in exfoliation glaucoma. The efficacy and safety of repeat SLT are shown in multiple studies, and the timing of repeat procedures may affect the success rate.