Selective vs argon laser trabeculoplasty: hypotensive efficacy, anterior chamber inflammation, and postoperative pain

Quantification of Postoperative Inflammation in Laser and Surgical Procedures for Glaucoma with Laser Flare Photometry: A Review of the Literature

PURPOSE

To review the application of laser flare photometry (LFP) in the objective quantification of aqueous flare (anterior chamber inflammation) post laser and surgical procedures for glaucoma.

METHODS

A search was undertaken using the following: PubMed (all years), the Web of Science (all years), Ovid MEDLINE (R) (1980 to 30 March 2023), Ovid MEDLINE (R) Daily Update 30 March 2023, MEDLINE and MEDLINE non-indexed items, Embase (1980-2021, week 52), Ovid MEDLINE (R) and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1980 to 30 March 2023), CENTRAL (including Cochrane Eyes and Vision Trials Register), metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). Search terms included "aqueous flare," "anterior chamber inflammation," "tyndallometry," "laser flare photometry" combined with "laser," "iridotomy," "trabeculoplasty," "cataract surgery," "phacoemulsification," "glaucoma surgery," "minimally invasive glaucoma surgery," "trabeculectomy," "aqueous shunt," "glaucoma drainage" and "cyclophotocoagulation."

RESULTS

The majority of studies utilizing laser flare photometry in grading flare have been post laser trabeculoplasty. The degree of flare produced varies according to the type of glaucoma laser or surgery performed, with filtration procedures and glaucoma drainage devices having marked and prolonged detectable levels. Aqueous flare in cyclodestructive procedures positively correlated with intraocular pressure (IOP) reduction.

CONCLUSION

In comparison to clinician grading, laser flare photometry provides a more objective measure of post-surgical inflammation in eyes that have undergone laser and surgery for glaucoma. Further research is warranted into how this instrument can be utilized to identify eyes at high risk of failure and other adverse outcomes after glaucoma surgery.

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.

Direct selective laser trabeculoplasty in open angle glaucoma study design: a multicentre, randomised, controlled, investigator-masked trial (GLAUrious)

INTRODUCTION

Laser trabeculoplasty is an effective and widely used treatment for glaucoma. A new laser technology, the Eagle direct selective laser trabeculoplasty (DSLT) device, may provide automated, fast, simple, safe and effective laser treatment for glaucoma in a broader range of clinical settings. This trial aims to test the hypothesis that translimbal DSLT is effective and not inferior to selective laser trabeculoplasty (SLT) in reducing intraocular pressure (IOP) in open angle glaucoma (OAG).

METHODS AND ANALYSIS

This is a multicentre, randomised, controlled, investigator-masked study. The primary efficacy outcome is intergroup difference in mean change from baseline IOP measured at 6 months. Secondary outcomes include mean percentage reduction in IOP at 3, 6 and 12 months; proportion of participants with at least 20% reduction in IOP from baseline at 6 months; change in ocular hypotensive medications at 12 months and evaluation of safety. Participants were aged >= 40 years with OAG, including exfoliative or pigmentary glaucoma, or ocular hypertension with untreated or washed out IOP 22-35 mm Hg.

TREATMENTS

DSLT: 120 shots, 3 ns, 400 µm spot size, energy 1.4-1.8 mJ delivered at the limbus over 2 s. SLT: approximately 100 shots, 3 ns, 400 µm spot size administered 360 degrees at the limbus using any gonioscopy lens, energy 0.3-2.6 mJ. A sample size of 164 is sufficient to detect a non-inferiority margin of 1.95 mm Hg for change from baseline IOP.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03750201, ISRCTN14033075.

The IOP lowering effects of "planning" selective laser trabeculoplasty in open angle glaucoma

Purpose

To investigate whether the planning of selective laser trabeculoplasty (SLT) influences the intraocular pressure (IOP) in patients with open angle glaucoma (OAG).

Methods

In this retrospective case-control study conducted on patients with OAG who planned to undergo SLT treatment (SLT group) or a visual field examination (VF group), we collected the demographic data, IOP on the planning day and on the scheduled day of the SLT treatment or VF examination. ΔIOP was defined as the IOP change between the planning day and the scheduled day. We used multivariable regression analyses and linear mixed model to evaluate the association between the abovementioned factors and ΔIOP in the VF group and the treatment eye (SLT_t) and fellow eye (SLT_f) of the SLT group.

Results

One hundred and fifty-three eyes of 102 patients with OAG were included, of which 51 patients in the SLT group and 51 patients in the VF group. The ΔIOP was −1.92 ± 2.77 mmHg in the SLT_t, −0.65 ± 2.47 mmHg in the SLT_f and −0.08 ± 1.73 mmHg in the VF group (P < 0.05). Both multivariable regression analysis between the VF and SLT_t group and linear mixed model in the SLT group showed significant negative association between the ΔIOP and SLT arrangement (P < 0.05). There was no significant association between ΔIOP and age, gender, baseline IOP, IOP fluctuation, nor SE.

Conclusions

The IOP was significantly reduced in patients with OAG after “planning” of SLT treatment, even without actual performing the laser treatment in our retrospective case-control study.

Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy

Aim

To evaluate the efficacy of selective laser trabeculoplasty (SLT) in Southeast Asian eyes with primary open-angle glaucoma (POAG) vs primary angle-closure glaucoma after peripheral iridotomy (PACG-PI).

Materials and methods

Records of glaucoma patients who underwent SLT and had a 24-month follow-up were reviewed. Pre- and post-treatment intraocular pressure (IOP), percentage of IOP reduction in POAG, and PACG-PI groups, and probability of failure were analyzed. SLT failure was defined as any eye that did not have IOP lower than 20% compared to the baseline or had an IOP higher than the baseline on two consecutive visits. Adding medication, repeating SLT, or surgical intervention to control IOP was also considered a failure.

Results

Sixty-three POAG and 12 PACG-PI eyes were eligible. The mean (standard deviation [SD]) age was 62.9 (10.2) years in POAG and 60.3 (6.2) years in PACG-PI. Mean (SD) prelaser IOP in POAG was 19.0 (4.4) mm Hg and 20.7 (4.7) mm Hg in PACG-PI. At 24 months post-SLT, mean (SD) IOP was 14.1 (4.7) mm Hg and 13.6 (2.0) mm Hg in POAG and PACG-PI, respectively. There was no significant difference in percentage of IOP reduction (22.8 ± 23.0% for POAG and 30.7 ± 19.5% for PACG-PI, p = 0.96), or failure probability (p = 0.10) between both groups.

Conclusion

The efficacy of SLT at 24 months was comparable between POAG and PACG-PI.

Clinical significance

Selective laser trabeculoplasty may be an option to further lower IOP in eyes with angle closure with visible trabecular meshwork (TM) after iridotomy, especially in highly pigmented eyes of Southeast Asians.

How to cite this article

Wongwuticomjon T, Chansangpetch S, Inobhas A, et al. Efficacy of Selective Laser Trabeculoplasty in Primary Angle-closure Glaucoma after Peripheral Iridotomy. J Curr Glaucoma Pract 2022;16(2):124-127.

Laser Trabeculoplasty for Open-Angle Glaucoma: A Systematic Review and Network Meta-Analysis

PURPOSE

We sought to comprehensively evaluate the effectiveness of different types of laser trabeculoplasty (LT) in the treatment of open-angle glaucoma.

DESIGN

Systematic review and network meta-analysis.

METHODS

Eligible randomized controlled trials were identified by searching PubMed, EMBASE, Cochrane Library, SCOPUS, China National Knowledge Infrastructure, and the Chinese Biomedical Literature Service System for studies published between January 1, 2000 and April 20, 2020. Eight interventions were evaluated, including argon LT (ALT), medications, 180-degree selective LT (SLT), 270-degree SLT, 360-degree SLT, new LT, transscleral 360-degree SLT with SLT performed without gonioscopy, and low-energy 360-degree SLT. The primary outcome was reduction of medicated and unmedicated intraocular pressure (IOP) at 6 months. Secondary outcomes included reduction of IOP at 12 months, incidences of complications, and change in number of medications. Head-to-head meta-analysis and network meta-analysis were performed using Stata and R software.

RESULTS

In total, 22 studies were included, involving 2859 eyes of 2704 patients. In terms of IOP reduction at 6 and 12 months, there were no statistically significant differences in both medicated and unmedicated IOP between any pairs of interventions considered herein, as determined based on both head-to-head and network meta-analyses (all P > .05). In terms of reduction of medications, the individuals treated with 180-degree SLT required fewer medications than those treated with ALT at 12 months (0.28 [95% confidence interval, 0.06-0.50]; P = .014). No severe adverse outcomes were reported for any of the interventions.

CONCLUSIONS

All the available types of LT are equally effective for decreasing IOP compared with medication-based therapy. The 180-degree SLT was slightly more effective than ALT in terms of reducing the number of medications needed. Additional well-performed randomized controlled trials with larger sample sizes are needed.

Low-energy Selective Laser Trabeculoplasty Repeated Annually: Rationale for the COAST Trial

The recent Laser in Glaucoma and Ocular Hypertension Trial provided the evidentiary basis for a paradigm shift away from the historical medication-first approach to glaucoma--which has numerous limitations, the most important of which is poor adherence to therapy --and toward a laser-first approach. Now 20 years after its commercialization, selective laser trabeculoplasty (SLT) is routinely performed consistently with its initial description, with energy titrated to the appearance of fine, champagne-like cavitation bubbles. A recent data set suggested that lower energy SLT, applied as primary therapy and repeated annually irrespective of intraocular pressure--rather than pro re nata when its effect wanes and irrespective of intraocular pressure rises --yields longer medication-free survival than standard energy SLT repeated pro re nata. A new study--Clarifying the Optimal Application of SLT Therapy --has been initiated to explore this preliminary finding in a pair of consecutive randomized trials. Herein, we provide an evidence-based rationale for the use of low-energy SLT repeated annually as primary therapy for mild to moderate primary open-angle glaucoma or high-risk ocular hypertension.

Automated Direct Selective Laser Trabeculoplasty: First Prospective Clinical Trial

Purpose

Direct selective laser trabeculoplasty (DSLT) is a rapid, noncontact automated procedure performed directly through the limbus without gonioscopy. In this first nonrandomized clinical trial we assessed its safety and ability to reduce intraocular pressure (IOP).

Methods

Fifteen patients (15 eyes: 10 with open-angle glaucoma [OAG], 4 with ocular hypertension, and 1 with pseudoexfoliation glaucoma), naive or after medication washout, with an IOP ≥22 mm Hg, underwent DSLT by irradiation with 100 or 120 sequential noncontact 532-nm, Q-switched laser shots (0.8-1.4 mJ) automatically applied during 1.5 or 2.3 seconds on the limbus, guided by image analysis and eye tracking. Results were assessed at 1 and 3 hours, 1 day, 1 week, and 1, 3, and 6 months.

Results

The mean ± standard deviation baseline IOP (mm Hg) in all eyes was 26.7 ± 2.3. At 1, 3, and 6 months, this value was significantly reduced to 21.7 ± 4.2 (by 18.1%), to 20.8 ± 2.5 (by 21.4%), and to 21.5 ± 4.1 (by 18.8%), respectively. In six patients treated with 1.4 mJ/shot, the mean IOP at 6 months decreased from 26.7 ± 3.2 to 19.3 ± 2.0 (27.1%, P = 0.03). There was a significant reduction in hypotensive medications (from 1.6 ± 1.0 to 0.4 ± 0.7, P = 0.03). No serious adverse events occurred.

Conclusions

Automated DSLT appears to be an effective and safe noncontact, rapid modality for reducing IOP in patients with OAG. Higher energy usage led to better results.

Translational Relevance

Studying laser transmission through sclera enabled laser irradiation of the trabeculum without gonioscopy.

Short-Term Efficacy of Selective Laser Trabeculoplasty in Omani Eyes with Glaucoma: A Single Institutional Study

Purpose

There is some evidence suggesting a different nature of response to selective laser trabeculoplasty (SLT) among different races. Therefore, we aimed to assess the short-term efficacy, safety and nature of outcome of SLT in Omani eyes.

Patients and Methods

A retrospective review was performed of patients with open-angle glaucoma (OAG) or ocular hypertension (OHTN) who underwent a single session of 360-degree SLT between January 1, 2017 and December 31, 2018. The main outcome was mean IOP reduction and attainment of treatment success at 5 weeks and 12 weeks post treatment defined as at least 20% IOP reduction from baseline without further medications or interventions. Secondary outcomes were frequency of adverse events and factors predicting success.

Results

A total of 33 eyes of 33 Omani patients who underwent treatment with SLT were analyzed. The nature of response to laser followed a gradual pattern as the mean IOP reduction from baseline was 20.2% (5.21 mm Hg, P <0.001) at 5 weeks and further enhanced to 27.2% (6.95 mm Hg, P <0.001) at 12 weeks. Short-term success was achieved in 51.5% and 72.2% of eyes at 5 and 12 weeks, respectively. SLT was most effective in OHTN subgroup and those with higher baseline IOP (both P <0.001). Side effects were an infrequent occurrence, minor and transient.

Conclusion

The short-term success of SLT in Omani eyes was clinically relevant and comparable to the gradual pattern seen in patients of Indian ancestry. It is a safe therapeutic option in selective Omani eyes.

Non-contact direct selective laser trabeculoplasty: light propagation analysis

Selective laser trabeculoplasty (SLT), used to treat glaucoma and ocular hypertension, requires the use of a gonioscope placed on the cornea to visualize and irradiate the trabecular meshwork (TM). Alternatively, non-contact direct SLT (DSLT) irradiates the TM through the overlying tissues. Here we analyze this innovative procedure using analytical modeling and Monte Carlo simulations to quantify the laser energy reaching the TM through the overlying tissues. Compared with energy launched from the laser, DSLT energy transmission to the TM is 2.8 times less than SLT, which verifies the efficacy of non-contact DSLT given the lowest reported effective SLT energies.

Laser Trabeculoplasty Perceptions and Practice Patterns of Canadian Ophthalmologists

Aim

To describe the current practice patterns and perceptions of Canadian ophthalmologists using laser trabeculoplasty (LTP).

Materials and methods

A cross-sectional survey of 124 members of the Canadian Ophthalmological Society (COS) who perform LTP was conducted. Descriptive statistics and Chi-square comparative analyses were performed on anonymous self-reported survey data.

Results

Of the 124 respondents, 34 (27.4%) completed a glaucoma fellowship. Use of selective laser trabeculoplasty (SLT) (94.4%) was preferred over argon laser trabeculoplasty (ALT) (5.6%). The most frequently cited reasons for SLT preference was less damage to trabecular meshwork (30.7%), availability (16.2%), and repeatability (16.2%). In all, 47.6% of the respondents performed LTP concurrently with medical treatment, 33.9% used it after medical treatment, and 17.7% used it as first-line treatment. Majority (87.1%) of the respondents believed that SLT is effective when repeated. In suitable patients, 41.9% of the respondents stated on average they repeat SLT once, 26.6% twice, and 19.4% greater than 2 times, respectively. Of those who repeat SLT on patients, 80.7% found repeat SLT treatments have good outcomes for patients. In all, 105 (84.7%) ophthalmologists responded they would benefit from an LTP practice guideline. Significantly more ophthalmologists without glaucoma fellowships perceived they would benefit from a practice guideline (p value <0.001).

Conclusion

This survey provides valuable practical information on how LTP is used in the treatment of glaucoma in Canada.

Clinical significance

The findings may serve as a baseline survey to trend future practices.

How to cite this article

Lee EY, Farrokhyar F, Sogbesan E. Laser Trabeculoplasty Perceptions and Practice Patterns of Canadian Ophthalmologists. J Curr Glaucoma Pract 2020;14(3):81–86.

The Role of Minimally Invasive Glaucoma Surgery Devices in the Management of Glaucoma

SIGNIFICANCE

Noncompliance is a problem affecting glaucoma patients. Approaches to improve adherence include the use of drug-delivery systems and safer forms of surgery. Minimally invasive glaucoma surgery (MIGS) has reduced complications, particularly in combination with cataract surgery, and with its good intraocular pressure (IOP) reduction may reduce or eliminate glaucoma medications.Glaucoma is a progressive disease and a leading cause of irreversible blindness. Elevated IOP is the most important risk factor, but effective medical management is dependent on patient adherence. This review summarizes the adherence problem in glaucoma and the efforts, including MIGS, to provide effective IOP control that is not dependent on patient compliance.The current understanding of patient adherence to pharmacological treatment of glaucoma is discussed including the challenges facing glaucoma patients. Historical approaches to providing IOP control in a sustained and reliable way are presented culminating in a review of the burgeoning use of MIGS devices.It is estimated that, in the United States, 27% of prescriptions written, across all medications, are not filled or are filled but not taken. For ocular hypotensive medications, even when filled, a large percentage (which varies widely by study) are not instilled as prescribed. To address this problem, methods for sustained drug delivery have been and continue to be developed, as well as surgical and laser approaches. Most recently, MIGS devices have gained popularity because of the ease of implantation during cataract surgery, favorable safety profile, and the possibility for effective and long-lasting IOP lowering, as well as the reduction or elimination of need for IOP-lowering medication.Poor adherence to treatment is relatively common among glaucoma patients and is associated with progression of disease. Recommending MIGS implantation during cataract surgery may offer optometrists a valuable treatment option in managing glaucoma patients, particularly where good adherence is in doubt.

The Rationale for Selective Laser Trabeculoplasty in Africa

Glaucoma is the leading cause of irreversible blindness in Africa. The condition is treatable but not curable. There are numerous obstacles to glaucoma care in Africa, including availability, accessibility and affordability of treatments, as well as medication nonadherence among patients. Medical therapy is costly relative to the average income in Africa and it requires daily self-dosing by patients. Surgery is of limited availability in many regions in Africa, and a high proportion of patients refuse surgery because it is expensive. Selective laser trabeculoplasty (SLT) proves to be a favorable alternative to medical or surgical care, as it is highly effective and safe in people of African descent, more cost-effective than medical therapy, quick and easy to perform, and portable. The procedure also requires no postoperative care, thus obviates the issue of nonadherence. In uncontrolled studies, SLT has a high response rate and it lowers intraocular pressure by 30% to 40%, which exceeds the goal in international guidelines for initial therapies. The African Glaucoma Consortium (AGC), a member-driven stakeholder collective, has been formed in part to develop the infrastructure for continent-wide improvements in glaucoma care. It embraces SLT as a potential key tool in their development plans. The mission of AGC includes improving clinical care by educating existing and new health care professionals to expand the provider network, by conducting trials to identify optimal care strategies for glaucoma in Africa, and by facilitating the development of an integrated network of Centers of Excellence to bring SLT and other crucial glaucoma therapies to communities throughout Africa.

Selective laser trabeculoplasty vs micropulse laser trabeculoplasty in open-angle glaucoma

Aim

The aim of this study was to prospectively compare the efficacy, safety, and tolerability of selective laser trabeculoplasty (SLT) vs micropulse laser trabeculoplasty (MLT) in reducing intraocular pressure (IOP) in open-angle glaucoma patients.

Patients and methods

In all, 38 patients were randomized to 360° MLT and 31 patients were randomized to 360° SLT. IOP was measured at intervals of 1 hour and 1, 1–6, 6–12, 6–24, 24–36, and 36–52 weeks. Patients completed a survey 1 week after the procedure. Patients with end-stage, neovascular, uveitic, or angle-closure glaucoma were excluded. Treatment response was defined as an IOP reduction of ≥20.0% or ≥3 mmHg from baseline.

Results

IOP was lowered to ≥3 mmHg from baseline among 37.0% of the micropulse patients and 36.0% of patients in the selective laser group at 24–52 weeks. Similarly, 29.6% of the micropulse patients and 36.0% of the selective laser patients experienced a 20.0% IOP decrease from baseline during the 24–52-week interval (P=0.77). Both groups revealed similar reductions in IOP as absolute values and percentage decreases from baseline at all intervals up to 52 weeks post treatment. There were more treatment failures in the micropulse group up to 52 weeks post laser treatment; however, this was not statistically significant. The micropulse group reported less pain both during and after the procedure (P=0.005).

Conclusion

Micropulse trabeculoplasty has demonstrated similar efficacy to SLT over a 52-week follow-up period with less discomfort experienced both during and after the procedure.

Efficacy of selective laser trabeculoplasty in primary angle closure disease

BACKGROUND

To study the role of selective laser trabeculoplasty (SLT) in intraocular pressure (IOP) reduction in post-laser iridotomy primary angle-closure disease patients with inadequately controlled IOP.

METHODS

In this prospective cross-sectional study, 34 patients with primary angle-closure disease with post-laser iridotomy open angles up to at least 180° were recruited. Following SLT, patients were examined at 1 day, 1 week, 1 and 3 months, 6 months and 1 year post SLT.

RESULTS

Data of 34 patients (34 eyes; 8 males and 26 females), with a mean age of 57.80 ± 6.44 years, were analysed. The reduction in IOP at each follow-up visit was significant (p < 0.001). The maximum reduction in IOP was noticed on post-laser day 1 and the least reduction was noticed 1 week post laser. Post-SLT range of IOP reduction varied from 9 to 46% at 1 year, which indicates the variability of a response to SLT. Mean IOP in both primary angle closure (PAC) and primary angle closure glaucoma (PACG) groups was comparable at all visits except at post-SLT week 1 when IOP in the PACG group was significantly higher than that in the PAC group (p = 0.035). None of the patients complained of pain and/or discomfort or had any clinically significant anterior segment inflammation on any of the follow-up visits. None of the patients underwent repeat SLT or surgery. The mean pre-SLT and post-SLT visual field index at 1-year follow-up was 95.47 ± 3.58 and 95.90 ± 4.13, respectively, which was not significant (p = 0.84).

CONCLUSIONS

High baseline IOP significantly correlated with reduction in IOP. Our results suggest that SLT is a safe, cost-effective modality for reducing IOP in primary angle-closure disease with patent laser iridotomy with a visible trabecular meshwork.

Could adverse effects and complications of selective laser trabeculoplasty be decreased by low-power laser therapy?

Selective laser trabeculoplasty (SLT) has been used for treatment of primary open-angle glaucoma, ocular hypertension, pigmenter and pseudoexfoliative glaucoma being considered a low-risk procedure. Therefore, transitory and permanent adverse effects have been reported, including corneal changes, subclinical edema, and reduction in endothelial cells and in central corneal thickness. Despite rarer, serious corneal complications after SLT can be permanent and lead to visual impairment, central corneal haze, opacity and narrowing. The mechanism involves increase of vasoactive and chemotactic cytokines causing inflammatory infiltrate, destruction of stromal collagen by fibroblasts and increase of matrix metalloproteinases type 2, which impair reepithelization. SLT also increases free radical production and reduces antioxidant enzymes, resulting in endothelium damages. Low-power laser therapy (LPLT) has been used in regenerative medicine based on its biostimulatory and anti-inflammatory effects. Biostimulation occurs through the interaction of laser photons with cytochrome C oxidase enzyme, which activates intracellular biochemical cascades causing synthesis of a number of molecules related to anti-inflammatory, regenerative effects, pain relief and reduction in edema. It has been showed that LPLT reduces gene expression related to pro-inflammatory cytokines and matrix metalloproteinases, and it increases expression of growth factors related to its proliferative and healing actions. Although radiations emitted by low-power lasers are considered safe and able to induce therapeutic effects, researches based on experimental models for glaucoma could bring important data if LPLT could be an alternative approach to improve acceptation for patients undergoing SLT.

Transscleral Selective Laser Trabeculoplasty Without a Gonioscopy Lens

PURPOSE OF THE STUDY

The purpose of the study was to investigate results of selective laser trabeculoplasty (SLT) performed directly on the sclera without a gonioscopy lens.

DESIGN

Interventional case series, prospective, randomized, masked, controlled clinical trial.

METHODS

Setting: Meir Medical Center, Kfar-Saba, Israel.

STUDY POPULATION

Adults with uncontrolled primary open angle or pseudoexfoliation glaucoma randomized into 2 groups.

INTERVENTION

The controls underwent conventional SLT with 100 spots delivered using a gonioscopy lens for 360 degrees of the trabecular meshwork. The study group underwent irradiation using the same parameters with the laser applications administered on the perilimbal sclera. Study visits: 1 hour, 1, 7, 30, 60, 180, and 365 days postprocedure.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP) and side effects.

RESULTS

Thirty adults were randomized into 2 groups. The mean (±SD) pretreatment IOP was 20.21±3.19 mm Hg for the study group (n=14) and 21.14±2.98 mm Hg for the controls (n=14; P =0.43), dropping to 15.50±3.77 and 15.00±4.08 mm Hg (P =0.74) after 6 months and to 16.00±3.31 and 14.00±2.45 mm Hg (P =0.22) after 12 months. The average IOP reduction after 6 and 12 months was 23.4% and 20.83% for the study group and 27.1% and 33.77% for the controls (P=0.528). Success (a decrease of ≥15% at 6 months with no additional medications, laser, or glaucoma surgery) was achieved in 12 (85.7%) study patients and 9 (69.2%) controls (P=0.385). Complications were mild and transient (n=30), although significantly higher in the controls (n=15; P <0.0001).

CONCLUSIONS

SLT applied directly to the perilimbal sclera may be as efficacious as the conventional procedure for 1 year.

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.

Feasibility of laser trabeculoplasty in angle closure glaucoma: a review of favourable histopathological findings in narrow angles

Selective laser trabeculoplasty (SLT) has been indicated as a safe and efficient treatment for primary open-angle glaucoma; however, recent studies have also shown positive results with the use of SLT in some clinical conditions related to primary angle-closure glaucoma (PACG). Despite the potential benefits of SLT in selected cases of PACG, the mechanisms underlying the modifications in the trabecular meshwork tissue of patients with PACG are poorly understood. This narrative review approached both the current, limited knowledge about the histological changes observed in different forms of PACG and the clinical results of SLT treatment for PACG. Favourable outcomes of SLT in patients with PACG, specifically in areas of non-occluded angle, need further substantiation through large controlled clinical trials. A deeper understanding of the biomolecular changes of those areas is essential to improve both laser technical details and the clinical efficacy of SLT therapy.

Corneal topographic alterations after selective laser trabeculoplasty

PURPOSE

To investigate the presence of corneal alterations in the long term among patients with primary open-angle glaucoma (POAG) after a single session of selective laser trabeculoplasty (SLT) treatment.

MATERIALS AND METHODS

The files of the POAG patients who had been treated with SLT were evaluated retrospectively. The Pretreatment Scheimpflug corneal topographic (SCT) findings were then compared with the post-treatment findings.

RESULTS

The files of 33 patients were eligible. The changes in central corneal thickness, thinnest point of cornea, and posterior corneal asphericity at 5 and 8 mm were statistically significant (p = 0.03, 0.01, 0.02, and 0.04 respectively). On the other hand, the simulated K, anterior 3 mm K, anterior 5 mm K, posterior 3 mm K, posterior 5 mm K, anterior asphericity at 3 mm, posterior asphericity at 3 mm, and Zernike values did not change significantly following the treatment (p = 0.19, 0.08, 0.1, 0.3, 0.2, 0.75, 0.09, and 0.3 respectively).

CONCLUSION

SLT can slightly alter pretreatment SCT findings in 3-6 months. Clinicians should wait for at least 6 months after SLT before performing any subsequent surgeries that depend on corneal parameters.

Intraocular Pressure-Lowering Potential of Subthreshold Selective Laser Trabeculoplasty in Patients with Primary Open-Angle Glaucoma

Purpose. To compare the efficacy of subthreshold and conventional selective laser trabeculoplasty (SLT) in lowering intraocular pressure (IOP) in the patients with primary open-angle glaucoma (POAG). Methods. Fifty-two eyes from fifty-two POAG patients were randomized into two groups, one group treated with subthreshold SLT using two-thirds of the conventional energy and the other one treated with the conventional energy. IOP was measured with the Goldmann tonometer and the anterior chamber inflammation was determined using laser flare meter. Results. The initial energy dosage used in subthreshold SLT group was significantly lower than the amount of the energy used in conventional SLT group (0.4 ± 0.1 mJ versus 0.6 ± 0.1 mJ, P = 0.030). The total energy dosage was also significantly lower in subthreshold SLT group compared to the other group (37.6 ± 3.3 mJ versus 51.8 ± 5.7 mJ, P = 0.036). However, the level of inflammation in aqueous humor, amount of reduction in IOP, and the success rate in controlling IOP was the same in both groups. Conclusion. The efficacy of subthreshold SLT group in reducing IOP in POAG patients is comparable to the efficacy of conventional SLT group.

Where does selective laser trabeculoplasty stand now? A review

Background

Chronic treatment of glaucoma can present a challenge in patients who lack the means and/or the discipline to use daily glaucoma medication. We wondered if selective laser trabeculoplasty (SLT) could be a useful alternative.

Methods

Inclusion criteria: controlled trials comparing efficacy of SLT in adult patients with any form of open angle glaucoma or ocular hypertension and case reports on side effects of SLT. Two recent meta-analyses identified eight randomized clinical trials (RCTs) comparing the effect of SLT with medication (prostaglandin analogs) and with argon laser trabeculoplasty (ALT). We took these eight RCTs as reference base and calculated their success rates where they were not given. Other articles were added to elaborate on technique and side effects.

Results

Mean intraocular pressure (IOP) reduction after SLT was 3.8–8.0 mmHg after 6 months to 1 year. Mean success rate of SLT at 6 months to 1 year is 55–82 %. Higher IOP before laser predicts a higher IOP-lowering effect. In terms of mean IOP reduction, reduction in number of medications and treatment success, the effect of SLT was found to show no clinically relevant difference from that of contemporary medication (prostaglandin analogs) and from ALT.

Conclusions

The evidence indicates that SLT is an efficacious primary or adjunctive therapy for treating glaucoma.

24-h Efficacy of Glaucoma Treatment Options

Current management of glaucoma entails the medical, laser, or surgical reduction of intraocular pressure (IOP) to a predetermined level of target IOP, which is commensurate with either stability or delayed progression of visual loss. In the published literature, the hypothesis is often made that IOP control implies a single IOP measurement over time. Although the follow-up of glaucoma patients with single IOP measurements is quick and convenient, such measurements often do not adequately reflect the untreated IOP characteristics, or indeed the quality of treated IOP control during the 24-h cycle. Since glaucoma is a 24-h disease and the damaging effect of elevated IOP is continuous, it is logical that we should aim to understand the efficacy of all treatment options throughout the 24-h period. This article first reviews the concept and value of diurnal and 24-h IOP monitoring. It then critically evaluates selected available evidence on the 24-h efficacy of medical, laser and surgical therapy options. During the past decade several controlled trials have significantly enhanced our understanding on the 24-h efficacy of all glaucoma therapy options. Nevertheless, more long-term evidence is needed to better evaluate the 24-h efficacy of glaucoma therapy and the precise impact of IOP characteristics on glaucomatous progression and visual prognosis.

Current and Future of Laser Therapy in the Management of Glaucoma

There has been tremendous progress in the past decades in the utilization of lasers for treating patients with glaucoma. This article reviews the use of lasers in different areas of glaucoma, including the shift from argon laser trabeculoplasty (ALT) to selective laser trabeculoplasty (SLT), laser trabeculoplasty as an initial treatment for glaucoma, new laser trabeculoplasty procedures under investigation, and other recent laser treatment modalities such as endoscopic cyclophotocoagulation and laser-assisted deep sclerectomy.

Repeatability of selective laser trabeculoplasty

PURPOSE

To determine the intraocular pressure (IOP)-lowering efficacy of repeat 360° selective laser trabeculoplasty (SLT) in patients with open-angle glaucoma having undergone prior successful 360° SLT.

METHODS

A retrospective chart review of 38 eyes of 38 patients with open-angle glaucoma (primary, pseudoexfoliation or pigmentary glaucoma) uncontrolled on medical therapy who had undergone two successive 360° SLT treatments, in whom first SLT was deemed clinically successful through a minimum of 6 months follow-up and who were followed for a minimum of 30 days after second SLT. Mean IOP at each postoperative time point (1, 3, 6, 12, 18 and 24 months) was compared with baseline using paired t tests. IOP changes after initial and repeat SLT were evaluated separately.

RESULTS

Mean (SD) baseline IOP before initial SLT was 21.6 (4.8) mm Hg. Mean IOP following initial SLT was significantly below baseline through 24 months of follow-up, with mean IOP at months 1-24 ranging from 15.9 to 18.6 mm Hg. Mean baseline IOP before repeat SLT was 19.1 (3.9) mm Hg, with a significant reduction in IOP from baseline through 24 months follow-up with mean IOP ranging from 14.7 to 17.0 mm Hg. Kaplan-Meier survival analysis showed longer median survival time for repeat SLT compared with initial SLT. No safety issues were observed with repeat SLT.

CONCLUSIONS

Repeat SLT can restore IOP control in eyes with open-angle glaucoma that have previously undergone successful initial SLT. Repeat SLT achieves comparable absolute level of IOP control achieved by initial SLT.

Meta-analysis of selective laser trabeculoplasty versus topical medication in the treatment of open-angle glaucoma

Background

The aim of this study was to examine possible differences in clinical outcomes between selective laser trabeculoplasty (SLT) and topical medication in the treatment of open-angle glaucoma.

Methods

Pertinent prospective comparative controlled trials comparing SLT with medication were selected through extensive searches of the PubMed, Embase, Web of Science, Chinese Biomedicine Database, and the Cochrane Controlled Trials Register database from their inception up to March 2014. Efficacy estimates were measured by their weighted mean difference (WMD) to calculate the intraocular pressure reduction (IOPR) from baseline to endpoint and by the odds ratio (OR) to determine success rates.

Results

Five prospective studies, which met the predefined criteria, were included in the meta-analysis. Four studies were randomized clinical trials and one study was a prospective non-randomized clinical trial. There were a total of 492 eyes of 366 patients with open-angle glaucoma. Four studies involving 325 eyes compared SLT with medication in terms of the IOPR. The WMD of the IOPR from the baseline was 0.6 (95 % confidence intervals: −0.24,1.43) when comparing SLT with medication. No statistical heterogeneity was observed between studies (χ2 = 1.30, P = 0.75, I² = 0.0 %). All five studies reported success rates, with a pooled OR of 0.84 (95 % confidence intervals: 0.42, 1.68), which was not statistically significant. No statistical heterogeneity was observed between studies (χ2 = 5.98, P = 0.200, I² = 33.1 %). Subgroup and sensitivity analysis confirmed the high stability of the meta-analysis results.

Conclusions

Both SLT and topical medication demonstrate similar success rates and effectiveness in lowering intraocular pressure in patients with open-angle glaucoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-015-0091-2) contains supplementary material, which is available to authorized users.

Selective laser trabeculoplasty: current perspectives

Selective laser trabeculoplasty (SLT) has been used in the treatment of glaucoma for just over a decade. Here, we review the current literature in terms of suggested mechanism, efficacy, method of treatment, predictors of success, adverse events, repeatability, and cost of SLT. The exact mechanism by which SLT lowers intraocular pressure (IOP) remains unknown although circumstantial evidence has come in many forms in relation to structural alteration; oxidative stress and inflammatory responses; tight junction integrity; proliferative responses; and microbubble formation. SLT is as effective as argon laser trabeculoplasty and medications in reducing IOP in glaucoma and ocular hypertension. The treatment is not uniformly effective in all eyes, and its IOP-lowering effect decreases over time. High pretreatment IOP is the strongest predictor of success; however, significant pressure reduction has also been shown in normal-tension glaucoma and in patients already taking multiple antiglaucoma drops. Mild, transient adverse effects are common. Transient IOP spikes usually resolve quickly with or without antiglaucoma treatment but may be problematic in pigmented angles. The limited available evidence suggests SLT is repeatable and cost-effective for the treatment of glaucoma and ocular hypertension.

Long-term outcomes of selective laser trabeculoplasty (SLT) treatment in pigmentary glaucoma patients

PURPOSE

The aim of the present study was to assess the long-term efficacy of selective laser trabeculoplasty (SLT) treatment in patients suffering from pigmentary glaucoma (PG).

METHODS

Retrospective chart review of eyes suffering from PG that underwent SLT between January 1, 2005 and December 31, 2006. The primary outcome measure was time to failure after SLT treatment. Failure after SLT was defined as any 1 or more of the following: <20% intraocular pressure reduction, change in the medical treatment, performance of a further SLT treatment, and the patient being sent for surgery. All patients were treated over 180 degrees with SLT.

RESULTS

Thirty eyes of thirty patients were identified. The average time to failure after SLT was 27.4 months. The success rate after 12 months was 85%, after 24 months 67%, after 36 months 44%, and after 48 months 14%.

CONCLUSIONS

The long-term effects of SLT in PG when eyes were treated over 180 degrees seem to be low.

The hypotensive effect of selective laser trabeculoplasty depending on iridocorneal angle pigmentation in primary open angle glaucoma patients

INTRODUCTION

Selective laser trabeculoplasty (SLT) is applied to reduce intraocular pressure in primary open angle glaucoma therapy. It selectively subjects trabecular pigmented cells to a pulsed, frequency-doubled Nd:YAG laser. The biostimulatory effect on trabecular macrophages was also postulated even in low-pigmented angles. The aim of the study was to assess the hypotensive effectiveness of SLT depending on the degree of iridocorneal angle pigmentation.

MATERIAL AND METHODS

Sixty-three eyes of 53 patients with primary open angle glaucoma (POAG) were included in this study and than divided into three subgroups, dependind of iridocorneal angle pigmentation. All subjects underwent SLT on 270 degrees of the angle. Intraocular pressure (IOP) was assesed at baseline and 6 weeks after the laser procedure.

RESULTS

Six weeks post-SLT mean IOP reduction was 2.63 mm Hg. The degree of IOP reduction showed a significant correlation with angle pigmentation. Intraocular pressure fell by 2.06 mm Hg, 2.46 mm Hg and 4.75 mm Hg in subgroups with low, marked and high pigmentation, respectively.

CONCLUSIONS

The SLT procedure most effectively reduces IOP only in the subgroup of POAG patients with marked angle pigmentation and it is equal to clinically succesfull hypontesive therapeutic effect, according to European Glaucoma Society guidelines. However, lower hypotensive effect in other study subjects may also be the valuable addition to pharmacological therapy of glaucoma.

[Selective laser trabeculoplasty: results after a first and a second session, overall comparison and results for three indications]

PURPOSE

To compare the results obtained with SLT trabeculoplasty after an initial treatment (SLT-1) and after a second treatment (SLT-2). Subgroup analysis according to trabecular pigmentation and the existence of a high myopia.

MATERIALS AND METHODS

Retrospective study of 77 patients, 152 SLT sessions performed in the Ophthalmology Department of Clermont-Ferrand University Medical Center, 118 SLT-1, 34 SLT-2. Three comparable groups of patients were assembled: group 1 (glaucoma patients with normal or subnormal trabecular pigmentation), group 2 (glaucoma patients with high myopia), and group 3 (glaucoma patients with significant trabecular pigmentation). The results were compared between groups, for SLT-1 and SLT-2.

RESULTS

Intraocular pressure lowering was consistent with data reported in the literature. Comparison of the results of SLT-1 versus SLT-2 did not find any significant difference in terms of IOP change. However, after SLT-2, the IOP response appears significantly greater (P=0.03) in the group with significant trabecular pigmentation compared to the non-myopic group with normal trabecular pigmentation.

DISCUSSION

Our results are consistent with the literature for efficacy, tolerance and reproducibility of SLT. No reduction in SLT efficacy was observed after a second session. Trabecular pigmentation is not a predictor of the response after the first session. In the case of retreatment (SLT-2), the differences observed lead to the hypothesis that it may be appropriate to perform at least two SLT treatments in patients with significant trabecular pigmentation in order to obtain maximal effect. Myopia, a variable not previously studied, does not seem to influence SLT outcomes.

CONCLUSION

Trabecular pigmentation and the presence of myopia do not appear to be predictive of a successful first treatment. However, our study leads us to suggest the hypothesis that the maximal response of SLT in patients with significant trabecular pigmentation is not obtained until after at least two sessions. This observation opens an interesting perspective on the therapeutic strategy to adopt in the case of pigmentary glaucoma.

Mechanisms of selective laser trabeculoplasty: a review

Selective laser trabeculoplasty is a safe and effective treatment for glaucoma, with greater cost effectiveness than its pharmacological and surgical alternatives. Nevertheless, although the basic science literature on selective laser trabeculoplasty continues to grow, there remains uncertainty over the mechanism by which laser trabeculoplasty reduces intraocular pressure. To address this uncertainty, the evidence behind several potential biological and mechanical mechanisms of selective laser trabeculoplasty were reviewed. In particular, cytokine secretion, matrix metalloproteinase induction, increased cell division, repopulation of burn sites and macrophage recruitment were discussed. Refining our understanding of these mechanisms is essential both to understanding the pathophysiology of ocular hypertension and developing improved therapies to treat the condition.

Selective laser trabeculoplasty versus argon laser trabeculoplasty in patients with open-angle glaucoma: a systematic review and meta-analysis

Objective

To examine possible differences in clinical outcomes between selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT) in open-angle glaucoma at different times post-treatment.

Methods

Randomized controlled trials (RCTs) comparing SLT versus ALT were searched through August 2013. The main outcome measure was IOP, and secondary outcomes included the number of glaucoma medications, the success rate, and adverse events.

Results

Six RCTs, involving 482 eyes treated with laser trabeculoplasty, were included in the meta-analysis. For all patients (including first and previous laser trabeculoplasy), no significant difference in IOP lowering was observed between SLT and ALT at one hour (P = 0.40), one week (P = 0.72), one month (P = 0.37), six months (P = 0.08), one year (P = 0.34), two years (P = 0.58), three years (P = 0.34), four years (P = 0.47), and five years (P = 0.50). A statistically significant difference in favor of SLT was found when comparing the IOP reduction at three months after intervention (weighted mean difference (WMD): 1.19 mmHg [0.41; 1.97]; I²=0%; P = 0.003). For patients who were naive to laser, there was no significant difference of reduction in IOP comparing SLT with ALT at any time point. In patients’ previous LT, no statistically significant difference in IOP reduction was found at six months (WMD: 1.92 mmHg [-0.91; 4.74]; I² = 77.3%; P = 0.18). There was no significant difference in the reduction in the number of glaucoma medications, the success rate, or adverse event rates between the two treatments.

Conclusions

SLT has equivalent efficacy to ALT with a similar constellation of side effects. In the case of retreatment, SLT appears to be similar to ALT in IOP lowering at six months.

Selective laser trabeculoplasty (SLT) vs other treatment modalities for glaucoma: systematic review

PURPOSE

Systemic review to compare selective laser trabeculoplasty (SLT) to other glaucoma treatment options in terms of their intraocular pressure (IOP)-lowering effect.

METHODS

Searches of the following databases were performed: PubMed, Cochrane Central Register of Controlled Trials, Ovid, EMBASE, metaRegister of Controlled Trials, and ClinicalTrials.gov. Only randomised controlled trials (RCTs) published in peer-reviewed journals comparing SLT to other glaucoma treatment options were considered. The main outcome measure was the change in IOP from baseline.

RESULTS

An initial search of PubMed identified 23 RCTs with 17 meeting the inclusion criteria. Nine RCTs compared 180° SLT to 180° argon laser trabeculoplasty (ALT) and one trial compared 360° SLT to 360° ALT, all reporting no difference in terms of IOP reduction from baseline. One RCT reported better outcomes with SLT at 1 year but this effect regressed at 2 years. Three trials compared 360° SLT to medical therapy and found no difference between the two treatment options. One trial found greater IOP reduction with latanoprost vs 90° and 180° SLT, and greater IOP reduction with 180° and 360° SLT versus 90° SLT, however no differences were found between 360° SLT versus latanoprost or 360° vs 180° SLT. Two trials compared 180° SLT to 360° SLT finding no difference in IOP reduction. Two trials compared 180° SLT to 90° SLT, one finding no significant difference and one finding greater IOP reduction with 180° SLT over 90° SLT. One trial compared excimer laser trabeculotomy (ELT) to 180° SLT, finding no differences in IOP reduction up to 3 months follow-up but greater IOP reduction with ELT at time intervals between 9 and 24 months. There were no RCTs identified that compared SLT to surgery.

CONCLUSION

In terms of the IOP lowering effect, there is no difference between SLT and ALT. Three trials indicate no difference between 360° SLT and medical therapy, with one of the trials indicating greater IOP reduction with latanoprost over 90° and 180° SLT. Three trials indicate no difference between 180° SLT and 360° SLT. It is inconclusive whether 90° is less efficacious than 180° SLT. One trial reports greater IOP reduction with ELT over 180° SLT in the long term.

Selective laser trabeculoplasty: Does energy dosage predict response?

Background:

Selective laser trabeculoplasty (SLT) is a widely used treatment for open angle glaucoma, producing sustained reductions of intraocular pressure (IOP). The aim of this study was to evaluate the long-term relationship between SLT energy dosage and IOP reduction.

Materials and Methods:

A retrospective review was performed for patients receiving primary SLT therapy, with inclusion of subjects treated with 360° of SLT. Energy settings were collected upon treatment and IOP was collected at baseline up to 36 months. Pearson's correlation coefficient was used to determine whether there was a significant correlation between SLT energy and IOP reduction at all time points. Kaplan-Meier analysis with log-rank test was performed to determine the differences in IOP reduction ≥20% from baseline among those treated with low (<85 mJ), medium (85-105 mJ), and high (>105 mJ) energy SLT.

Results:

A total of 104 eyes (75 patients) were included. The mean total SLT energy was 93.73 mJ (standard deviation (SD) = 21.83 mJ, range: 34.4-122 mJ). A significant positive correlation (P ≤ 0.05) between the amount of energy delivered and IOP reduction was found at all time points. Log-rank test showed a significant difference in IOP reduction ≥20% from baseline between the three energy groups, with low energy patients experiencing failure at an earlier time (P = 0.05).

Conclusions:

Within the range of total energy examined, there is a positive correlation between total energy used and amount of pressure reduction achieved at up to 3 years of follow-up. This may be useful in determining the optimal energy dosage for maximum effect for patients receiving SLT.

Selective Laser Trabeculoplasty: A Clinical Review

Selective laser trabeculoplasty (SLT) is a safe and effective treatment modality for lowering the intraocular pressure in patients with glaucoma. It achieves its results by selective absorption of energy in the trabecular pigmented cells, sparing adjacent cells and tissues from thermal damage, with minimal morphological tissue alteration following treatment. On the basis of the peer-reviewed medical literature, SLT is efficacious in lowering IOP, as initial treatment or when medical therapy is insufficient in all types of open-angle glaucoma in all races. SLT achieves intraocular pressure reduction similar to that of argon laser trabeculoplasty but without the tissue destruction and side effects. Observed side effects following SLT were almost uniformly transient and minor. We review highlights of recently published studies on the mechanisms and clinical outcome of SLT in order to address frequently raised issues pertinent to SLT in the clinical practice.

KEY MESSAGES

Selective laser trabeculoplasty is a safe and effective treatment modality for lowering the intraocular pressure in patients with glaucoma. How to cite this article: Alon S. Selective Laser Trabeculoplasty: A Clinical Review. J Current Glau Prac 2013; 7(2):58-65.

The efficacy of selective laser trabeculoplasty versus argon laser trabeculoplasty in pseudophakic glaucoma patients

INTRODUCTION

This study evaluated and compared the efficacy of selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT) in terms of intraocular pressure (IOP)-lowering effects in pseudophakic patients at various time points after treatment. The primary aim was to compare the efficacy of SLT and ALT in reducing the IOP of pseudophakic glaucoma patients who recently underwent successful cataract extraction surgery. The secondary endpoint was to determine the percentage of SLT and ALT patients whose IOP was successfully reduced by at least 15% from baseline.

PATIENTS AND METHODS

This study was a follow-up of a prospective randomized clinical trial. Fifty-two eyes from 52 glaucoma patients with uncontrolled IOP who had previously undergone successful phacoemulsification-assisted cataract excision surgery with intracapsular lens implantation were randomly assigned to treatment with either ALT (n = 30) or SLT (n = 22). Fifteen patients were excluded due to adverse events encountered during the study, leaving a total of 18 and 19 patients in the ALT and SLT groups, respectively. IOP measurements were carried out at scheduled intervals until 12 months post-laser treatment.

RESULTS

There were no significant differences in the IOP-lowering effects between the two methods at any time point during the follow-up period. The greatest differences between the two groups were observed at 1 week posttreatment and at the 3-month time point, but neither reached a level of significance. At the final checkup, the mean IOP reduction from baseline was 3.23 mmHg in the ALT group and 4.30 mmHg in the SLT group (P = 0.269). At that visit, six (35.3%) patients in the ALT group and 15 (75%) patients in the SLT group had a reduction of ≥15% from their baseline IOP.

CONCLUSION

SLT and ALT are equally effective in their IOP-lowering capabilities in new pseudophakic glaucoma patients during the first 12 months after treatment.

Selective Laser Trabeculoplasty: An Overview

Given the obvious quality of life concerns with medical and surgical lowering of intraocular pressure (IOP), lasers have received considerable attention as a therapeutic modality for glaucoma. Selective laser trabeculoplasty (SLT) is increasingly being used in clinical practice as both the primary procedure and as an adjunct to medical and surgical therapy. Preliminary published evidence suggests that SLT is an effective, compliance-free, repeatable and safe therapeutic modality having only minor, transient, self-limiting or easily controlled side effects with no sequelae. This review attempts a broad overview of the current knowledge of its mechanism, efficacy, indications and limitations, point out the knowledge lacunae that still exist with respect to this highly promising technology which has captured the attention of glaucoma surgeons all over the world.

HOW TO CITE THIS ARTICLE

Jha B, Bhartiya S, Sharma R, Arora T, Dada T. Selective Laser Trabeculoplasty: An Overview. J Current Glau Prac 2012;6(2):79-90.