Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma

Comparing pattern scanning laser trabeculoplasty to selective laser trabeculoplasty: A randomized controlled trial

PURPOSE

To compare safety, tolerability and intraocular pressure (IOP)-lowering efficacy of pattern scanning laser trabeculoplasty (PSLT) with selective laser trabeculoplasty (SLT) in fellow eyes of untreated patients with glaucoma.

DESIGN

Randomized controlled trial.

PARTICIPANTS

Twenty-nine patients (58 eyes) with primary and secondary open angle glaucoma (OAG) were randomized to undergo PSLT or SLT in each eye.

METHODS

Pattern scanning laser trabeculoplasty was performed using the Pascal laser (Pascal Streamline 577; Topcon Inc., Tokyo, Japan). Patients' comfort level to treatment was assessed using a visual analogue scale (VAS). Follow-up visits were at week 1, month 1, 3 and 6. Success was defined as IOP reduction ≥20%.

MAIN OUTCOME MEASURES

Safety, tolerability and IOP reduction.

RESULTS

The mean age of patients was 54.1 ± 15.5 years. Baseline IOP was similar between both groups (PSLT, 17.3 ± 4.0 mmHg; SLT, 16.8 ± 3.6 mmHg, p > 0.05). In the PSLT group, the mean IOP at 1, 3 and 6 months was 14.2 ± 3.5, 13.9 ± 2.6 and 14.0 ± 2.7 mmHg, respectively. In the SLT group, the mean IOP at 1, 3 and 6 months was 14.4 ± 4.1, 13.7 ± 3.2 and 13.7 ± 3.1 mmHg, respectively. The IOP reduction in the PSLT group was greater than the SLT group at 1 month (p < 0.01) and 3 months (p < 0.01). VAS score was better in PSLT eyes: 23.9 ± 20.5 (range, 0-82) than in SLT eyes: 50.4 ± 25.3 (range, 0-98) (p < 0.001). No serious adverse events were recorded.

CONCLUSIONS

Both laser modalities had similar safety and efficacy profiles while PSLT was better tolerated by patients.

Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty

PURPOSE

To evaluate the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) or ocular hypertension (OHT), when performed with laser pulse duration of 1 ns compared with standard 3-5 ns.

METHODS

Bilateral SLT with a 532 nm Q-switched neodymium-doped yttrium aluminium garnet laser was conducted in 30 patients (60 eyes) with POAG (n = 5), NTG (n = 2) or OHT (n = 23). Pulse duration was 1 ns in the right eye (30 eyes; cases) and 3-5 ns in all left eyes (controls). Main outcome measures were IOP at 1 h, 1 day, 8 weeks and 6 months, and the rate of adverse ocular tissue reactions in all eyes.

RESULTS

Mean 1 ns and 3-5 ns SLT IOPs were 24.1 and 24.3 mmHg, respectively, at baseline. No statistically significant difference in mean 1 ns and 3-5 ns SLT IOP was observed at 1 h (P = 0.761), 1 day (P = 0.758), 8 weeks (P = 0.352) and 6 months postoperatively (P = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (P = 0.529). Treatment with both laser pulse durations resulted in minor ultrastructural changes in the drainage angle.

CONCLUSIONS

SLT performed with a 1 ns laser pulse duration does not appear to be inferior to SLT performed with the standard 3-5 ns duration at lowering IOP in treatment-naïve patients with POAG, NTG or OHT.

Glaucoma treatment trends: a review

Glaucoma is one of the most common causes of blindness worldwide, and its prevalence is increasing. The aim of the present review is to describe the current medical and surgical treatment trends in the management of open-angle glaucoma. There has been an increase in the availability of glaucoma medications and the use of laser trabeculoplasty over the past decade, with a subsequent decrease in invasive incisional surgery. In addition, a new class of glaucoma procedures, termed microinvasive glaucoma surgery, has emerged, which aims to fill the gap between conservative medical management and more invasive surgery.

Predictors, Resource Utilization, and Short-term Costs of Laser Trabeculoplasty Versus Medication Management in Open-Angle Glaucoma

PURPOSE

Adjunctive laser trabeculoplasty (LT) is an alternative to topical medications for open-angle glaucoma (OAG). The purpose was to: (1) identify predictors of LT vs glaucoma medication treatment; and (2) estimate the resource utilization and short-term costs associated with LT vs medication management.

DESIGN

Retrospective administrative claims analysis.

METHODS

Medical and pharmacy claims data between 2007 and 2012 were analyzed to identify prostaglandin analogue monotherapy OAG patients with an index date LT claim or second medication class claim. Patients were followed for 12 months pre-index and 24 months post-index. Predictive LT attributes included age, sex, employment status, medication adherence, comorbidity status, and geographic region. Short-term costs included glaucoma-specific and comprehensive healthcare encounters. Cohort comparisons were analyzed using χ(2) and Student t tests, logistic regression (predictive), and generalized linear models (cost).

RESULTS

The study included 4743 LT and 16 484 medication patients. Baseline demographics were similar but significant differences were identified for comorbidities, adherence, and geography. Younger age (odds ratio [OR]: 1.21; P < .001), low adherence (OR: 1.18; P = .001), high comorbidities (OR: 1.12; P = .006), and region (OR: 1.50; P < .001) significantly predicted LT receipt. Within LT patients, 60% did not have a pharmacy claim 45 days post-index; by 2 years, this reduced to 20%. LT attributed significantly higher medical ($2684 vs $1980; P < .0001), lower pharmacy ($807 vs $1467; P < .0001), and greater overall costs ($3441 vs $3408; P = .325).

CONCLUSIONS

Poor adherence, younger age, and more comorbidities were predictors of receiving LT. Despite the potential for LT to address adherence, most patients had a medication claim within 2 years. Overall, LT does not provide glaucoma-specific cost savings.

Repeatability of selective laser trabeculoplasty for open-angle glaucoma

Background

To analyze the results of repeat selective laser trabeculoplasty (SLT).

Methods

Inclusion criteria: participants with primary or secondary open-angle glaucoma (excluding uveitic) who had undergone SLT 360° (SLT 1) with diminution of response over time followed by repeat SLT 360° (SLT 2). Six months of follow-up were required and at least 6 months in between SLT 1 and 2. The main outcome measures were IOP reduction at 6 and 12 months and a comparison of the response between SLT 1 and 2.

Results

One hundred thirty-seven patients met the inclusion criteria. If only one eye had repeat treatment, that eye was chosen; if both eyes qualified, one was chosen at random. The baseline intraocular pressure (IOP) for SLT 1 = 20.3+/− 5.2 mmHg and SLT 2 = 19.4 +/− 5.0 was reduced to 16.4 +/− 3.9 and 16.7 +/− 4.7 at 1 year, respectively (p < .001). Medication use was not significantly changed, and was 2.2 +/− 1.2 at baseline for SLT 1 and 2.1 +/− 1.3 for SLT 2, and at 1 year was 1.9 +/− 1.3 and 2.2 +/− 1.2, respectively. A subanalysis of 62 patients matched for equivalent baselines showed a baseline IOP = 18.7 +/− 3.8 for SLT 1 and 18.7 +/− 3.5 for SLT 2, reduced to 16.0 +/− 4.3 and 15.3 +/− 3.8 at 1 year (p < .001).

Conclusion

Repeat SLT laser (360-degree treatment, followed by a loss of effect over time, then a second 360-degree treatment) in this population resulted in IOP lowering similar to that of the initial treatment.

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.

The effect of repeat 360-degree selective laser trabeculoplasty on intraocular pressure control in open-angle glaucoma

OBJECTIVE

To evaluate the effect of repeat 360-degree selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) with short-term follow-up.

METHODS

This study was based on clinical practice (25 females and 13 males) with a history of primary open-angle glaucoma (27), normotensive glaucoma (6) or pseudoexfoliative glaucoma (5). We measured the IOP at baseline before the first and second 360-degree SLT at 1 month, 6 months and 15 months. Follow-up was concluded earlier if the SLT failed (an increase in IOP over the baseline value), if a new medication was introduced or if an IOP lowering surgery was performed.

RESULTS

Baseline IOP prior to SLT1 was 19.0 ± 3.7 mmHg, which dropped to 16.0 ± 3.7 mmHg (17.0% reduction), 16.9 ± 3.8 mmHg (12.5% reduction) and 17.2 ± 3.3 mmHg (8.7% reduction) at 1, 6 and 15 months respectively (P<0.01). For SLT2, baseline IOP was 18.0 ± 4.5 mmHg, which dropped to 15.1 ± 3.8 mmHg (15.1% reduction), 15.1 ± 4.3 mmHg (15.6% reduction) and 16.0 ± 3.6 mmHg (10.3% reduction) at 1, 6 and 15 months respectively (P<0.01).

CONCLUSION

In a cohort of patients who underwent 360-degree SLT 4 years previously, a second SLT resulted in IOP lowering similar to the first treatment with a possibly more sustained response.

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.

The Effect of Laser Trabeculoplasty on Posture-Induced Intraocular Pressure Changes in Patients with Open Angle Glaucoma

Purpose

To investigate the effect of argon laser trabeculoplasty (ALT) on posture-induced intraocular pressure (IOP) changes in patients with open angle glaucoma (OAG).

Methods

Thirty eyes of 30 consecutive patients with OAG who underwent ALT were prospectively analyzed. The IOP was measured using Icare PRO in the sitting position, supine position, and dependent lateral decubitus position (DLDP) before ALT and at 1 week, 1 month, 2 months, and 3 months after ALT.

Results

Compared to the baseline values, the IOP in each position was significantly decreased after ALT (all P < 0.001). During follow-up, the mean percentage of IOP reduction was similar in the sitting and supine positions, but was significantly lower in DLDP than in the sitting or supine positions (all P < 0.05). In terms of postural IOP changes, the IOP in the supine position and DLDP was significantly higher than that in the sitting position at the same time points during the follow-up period (all P < 0.001). The difference between the IOP in the supine position and DLDP during follow-up was significant (all P < 0.001). The extent of IOP differences between any positions did not show significant changes during the follow-up period (all P > 0.05).

Conclusions

ALT appears to be effective in lowering the IOP in various body positions, but the degree of this effect was significantly lower in DLDP. In addition, ALT seemed to have limited effects on posture-induced IOP changes.

Complications of selective laser trabeculoplasty: a review

Selective laser trabeculoplasty is a laser treatment to treat glaucoma. It was initially indicated for open-angle glaucoma but has been proven to be efficacious for various types of glaucoma. This review article summarizes the few rare complications that can be seen with selective laser trabeculoplasty. It also makes recommendations on how to avoid these problems and how to treat patients when these rare complications arise.

Selective Laser Trabeculoplasty: An Update

Selective laser trabeculoplasty (SLT) is an effective treatment option for the reduction of intraocular pressure (IOP) in patients with ocular hypertension or open-angle glaucoma. The mechanism by which SLT lowers IOP is not completely understood and is likely multifactorial. Published studies indicate that SLT is at least as effective as argon laser trabeculoplasty or medications at lowering IOP in many forms of glaucoma. In addition to IOP reduction, SLT may decrease IOP fluctuation and can be successfully used as primary or adjunctive therapy for the management of both early and advanced glaucoma. However, SLT may not be effective in certain forms of glaucoma, and the IOP-lowering effect seems to wane with time. High pretreatment IOP is the strongest predictor of treatment success, even in patients with normal-tension glaucoma. Repeatability of SLT has been controversial, but recent evidence suggests that it can be successfully repeated to achieve additional or recurrent IOP reduction, even in eyes that only had a modest response to initial treatment. Adverse events are uncommon after SLT, and the most common complications such as discomfort and inflammation are typically mild and transient. Further investigation is required to determine the optimal treatment parameters for SLT treatment. Limited evidence suggests that SLT is cost-effective as primary therapy for patients with glaucoma.

Long-term outcomes in patients initially responsive to selective laser trabeculoplasty

AIM

To determine the long-term effects of selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) and the number of medications used up to 5y following treatment in glaucoma patients receiving maximally tolerated medical therapy (MTMT).

METHODS

The Wills Eye Hospital Glaucoma Research Center retrospectively reviewed the charts of glaucoma patients who underwent SLT after receiving MTMT. Eyes that did not achieve their target pressure within 3mo following SLT were excluded from the study. Changes in mean IOP and number of glaucoma medications used were analyzed at 1, 3, and 5y following SLT.

RESULTS

Seventy-five eyes of 67 patients were included in the study. Fifteen eyes that received SLT failed to achieve their target pressure within 3mo and were excluded from the study. The average follow-up time was 37.4mo (±14.4). Mean IOP was significantly reduced 1y after treatment (P=0.005). It was also reduced 3, 5y after treatment without reaching statistical significance (P=0.20 and P=0.072, respectively). There was a significant decrease in mean number of medications used 1, 3, 5y after treatment (P<0.001, P<0.001, and P=0.039, respectively). In the span of 5y, 2 eyes (2.7%) underwent repeat SLT, 7 eyes (9.3%) underwent glaucoma surgery and an additional 3 eyes (4.0%) underwent both.

CONCLUSION

SLT significantly reduced the number of glaucoma medications used 5y following treatment in glaucoma patients receiving MTMT. SLT may delay operating-room surgery.

[Current aspects on the management of normal tension glaucoma]

In a considerable proportion of glaucoma patients (25-50 %) the intraocular pressure (IOP) is not elevated higher than 22 mmHg at first diagnosis and during subsequent follow-up controls. Although the IOP level remains in the low range < 22 mmHg, progression of glaucoma can still occur. A multitude of different factors are assumed to be involved in glaucoma progression, such as very low nocturnal diastolic blood pressure values, a low mean ocular perfusion pressure, extensive fluctuations in perfusion (e.g. in cases of vascular dysregulation), an increased vulnerability of the optic nerve support structures, an increased translaminar pressure gradient and various underlying systemic diseases. The most important evidence-based aspect of treatment in normal tension glaucoma is pharmaceutical or surgical reduction of the IOP by 30 % or more in comparison to the initial pressure level. Vascular and neuroprotective concepts of treatment for normal tension glaucoma have been strongly advocated and the object of experimental and clinical studies. As yet a clear clinical benefit has not been proven by large prospective randomized studies.

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.

Selective laser trabeculoplasty as a first-line therapy: a review

Poor adherence with glaucoma medications has been well documented. There remains a significant unmet need for a relatively safe intraocular pressure (IOP)-lowering procedure that minimizes or eliminates patient participation, and thus reduce the incidence of treatment failures attributable to nonadherence. Selective laser trabeculoplasty (SLT) offers several advantages: It effectively reduces IOP in most patients with open-angle glaucoma, it is cost-effective compared with eye drops, it can be repeated if needed, and it eliminates the issue of adherence to medications when used as an initial treatment. This article reviews the evidence supporting the use of SLT as a first-line therapy in glaucoma.

Efficacy of selective laser trabeculoplasty in phakic and pseudophakic eyes

PURPOSE

To compare the efficacy of selective laser trabeculoplasty (SLT) in phakic and pseudophakic eyes in open-angle glaucoma and ocular hypertension.

MATERIALS AND METHODS

Charts of 28 pseudophakic eyes and 60 phakic eyes that underwent 360-degree SLT were retrospectively reviewed. Patients were examined at 1, 3, 6, and 12 months. Treatment success was defined as ≥20% intraocular pressure (IOP) reduction, with no additional medications, laser, or glaucoma surgery. Mean IOP change, mean percentage of IOP reduction, and success rates for phakic and pseudophakic eyes were compared.

RESULTS

Mean percentage of IOP reduction post-SLT at 1-, 3-, 6-, and 12-month visits were 21.4%, 25.8%, 24.8%, and 23.7%, respectively, in the pseudophakic group and 22.8%, 25.0%, 25.7%, and 21.2%, respectively, in the phakic group. Success rates ranged between 60% and 64% in the pseudophakic group and between 58% and 73% in the phakic group. No statistically significant differences in IOP change, percentage of IOP reduction, and success rate were seen between the groups at any of the post-SLT visits (P>0.05).

CONCLUSIONS

Application of 360-degree SLT seems to be an efficient and safe treatment option for the management of phakic and pseudophakic open-angle glaucoma and ocular hypertension.

Noninvasive glaucoma procedures: current options and future innovations

Noninvasive glaucoma procedures (NIGPs) represent a new dawn in the management of glaucoma. They try to fill the gap between the shortcoming of invasive glaucoma surgeries and antiglaucoma medications. NIGPs were introduced as an adjunct or alternative treatments for glaucoma. Some of these procedures have shown good efficacy with few serious complications. Hence, they are now used as both primary and adjunctive therapy for glaucoma. The most common NIGPS involve laser and ultrasound technologies. Currently, the portfolio of NIGPs includes argon laser trabeculoplasty, selective laser trabeculoplasty, and micropulse diode laser trabeculoplasty. More recent innovations include therapeutic ultrasound for glaucoma, ultrasonic circular cyclocoagulation, and deep wave trabeculoplasty.

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.

[Selective Laser Trabeculoplasty in the treatment of chronic open-angle glaucoma: retrospective analysis 12 years after treatment in a cohort of 28 patients]

PURPOSE

To determine long-term efficacy of selective Laser Trabeculoplasty (SLT) over 12 years in chronic open-angle glaucoma (OAG) patients.

METHODS

In this retrospective study, all patients treated by SLT between 1997 and 1999 for OAG were included and followed up every 6 months. The procedure was performed with a Coherent Selecta 7000 Nd:YAG with 100 ± 10 non overlapping 400 μm spots over 360 degrees centered on the trabecular meshwork. Patients were excluded in the case of prior filtration surgery or Argon laser trabeculoplasty. Our primary study parameter was the number of patients requiring filtration surgery within the follow-up period. Our secondary parameters were intraocular pressure (IOP) and SLT-related complications.

RESULTS

We included 46 eyes of 28 patients. The 12-year success rate was 26.1%. Thirty-nine percent of all eyes underwent filtration surgery (failure) during the follow-up period, and 34.8% were lost to follow-up. In the pigmentary glaucoma (PG) subgroup, the 12-year success rate was 16%, while it was 37.5% in the Primary OAG subgroup. The overall mean IOP was 22.8 mm Hg (D.S. 3.78) prior to laser, 16.08 mm Hg (D.S. 2.7) at 1 year and 15 mm Hg (D.S. 1.8) at 12 years. The mean number of medications was 1.6 (D.S. 0.8) prior to SLT, 1.36 (D.S. 0.8) at 1 year, and 1.3 (D.S. 1.2), 12 years after SLT respectively. No patients had a second SLT treatment. No significant complications occurred during follow-up.

CONCLUSION

Selective laser trabeculoplasty may at times be a useful resource to lower IOP in patients with OAG. Nonetheless, the failure rate is significant especially in PG, which requires confirmation by larger prospective studies.

Frequency of visual field testing when monitoring patients newly diagnosed with glaucoma: mixed methods and modelling

Background

Visual field (VF) tests are the benchmark for detecting and monitoring the eye disease glaucoma. Measurements from VF tests are variable, which means that frequent monitoring, perhaps over a long period of time, is required to accurately detect true glaucomatous progression. In 2009, guidelines for the diagnosis and management of glaucoma issued by the National Institute for Health and Care Excellence revealed an absence of research evidence about the clinical effectiveness and cost-effectiveness of using different monitoring intervals to detect disease progression. However, the European Glaucoma Society (EGS) guidelines on patient examination recommend that newly diagnosed glaucoma patients should undergo VF testing three times per year in the first 2 years after initial diagnosis.

Objectives

The primary objective of this project was to explore the clinical effectiveness and cost-effectiveness of using different monitoring intervals to detect VF progression in newly diagnosed glaucoma patients. Other objectives sought to (1) explore glaucoma patients’ views and experiences of monitoring using focus groups; and (2) establish glaucoma subspecialists’ attitudes regarding frequency of VF testing using a five-item questionnaire.

Design

These questions were investigated using a multicentre audit of current practice and existing NHS data (VF records from almost 90,000 patients). New research knowledge was provided through statistical and health economic modelling of these and additional published data.

Results

The multicentre audit showed that VF monitoring is, on average, carried out annually. Patient focus groups indicated that, although patients do not like VF testing, they accept it as a critical part of their care. Patients raised concerns regarding distracting testing environments, quality of instructions, explanation of results and excessive waiting times. Questionnaires revealed that clinicians’ attitudes towards the frequency of VF testing varied considerably, and many glaucoma specialists believed that current recommendations are impractical. Statistical modelling suggested that EGS recommendations could be clinically effective as progression can be identified sooner than is possible with annual testing. Health economic modelling suggested that increased VF monitoring may also be cost-effective [incremental cost-effectiveness ratio (ICER) was equal to £21,679].

Conclusions

Statistical modelling of VF data suggests there is strong rationale for following EGS recommendations with the primary benefit of providing better information about fast-progressing patients. Our health economic model suggested that increasing VF testingmaybe cost-effective (ICER was equal to £21,679), especially when accounting for gains to society. Nevertheless, many clinicians consider increased VF testing of patients impossible with current resources. In addition, patient focus groups raised concerns about the practicalities of delivery of VF tests.

Future work

Results from this study could inform the design of a prospective randomised comparative trial of different VF monitoring intervals in glaucoma linked to stratifying patients according to risk factors for progression. The statistical model for VF data can be further developed to be used as a practical tool for optimising individualised follow-up. The views of clinicians and patients indicate that service delivery of VF testing is an important issue and worthy of further investigation. Ensuring the confidence and co-operation of the patient should be at the centre of future research into the most efficient strategies for glaucoma monitoring.

Funding

This work was funded by the National Institute for Health Research Health Services and Delivery Research programme.

[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.

Clinical results of selective laser trabeculoplasty in silicone oil-induced secondary glaucoma

BACKGROUND

To analyze the efficacy of selective laser trabeculoplasty (SLT) on silicone oil-induced secondary glaucoma in terms of intraocular pressure (IOP).

PATIENTS AND METHODS

42 patients (42 eyes) with silicone oil-induced secondary glaucoma were selected, and SLT was performed with 360° of the trabecular meshwork. During the 12-month follow-up, the complications, IOP, and antiglaucoma medication usage were observed.

RESULTS

The mean IOP decreased from 23.1 ± 1.9 mmHg before treatment to 18.4 ± 3.7 mmHg after treatment (p < 0.05). Mean number of antiglaucoma medications used for IOP control also decreased from 2.17 ± 1.21 to 1.25 ± 0.89 (p < 0.05). The 12-month success rate in the total sample was 59.5 %. The success rate was 60.7 % (17 eyes) and 57.1 % (eight eyes) for phakic and aphakic eyes, respectively (p > 0.05) CONCLUSIONS: SLT is a safe and effective option for the treatment of patients with silicone oil-induced secondary glaucoma.

Efficacy of selective laser trabeculoplasty in medically uncontrolled glaucoma

Purpose. To investigate the efficacy and safety of 360° selective laser trabeculoplasty (SLT) on medically uncontrolled open-angle glaucoma (OAG) and to evaluate the effects of antiglaucomatous medications on the results of therapy. Materials and Methods. The medical records of 62 eyes of 51 patients with OAG, which did not reach the targeted intraocular pressure (IOP) with maximum antiglaucomatous medical therapy, were retrospectively reviewed. Results. A statistically significant decrease was observed in the mean baseline IOP at 1, 3, 6, and 12 months of followup (P < 0.01). The success rate was 64.5% in all of the patients. The success rates did not vary significantly by taking 1, 2, 3, or 4 medications with the rates of 63.6%, 71.4%, 64.2%, and 58.3% (P = 0.06). The success rate of eyes on medication more or less than 6 months was 62.5% or 66.7%, respectively (P = 0.3). There was a positive correlation between mean baseline IOP and mean reduction in IOP from baseline (P < 0.001, r = 0.8). Conclusion. Application of 360° of SLT provided an effective and safe IOP reduction in medically uncontrolled OAG. Baseline IOP was found to be the most important factor in the efficacy of therapy.

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.

Influence of Selective Laser Trabeculoplasty (SLT) on combined clear cornea phacoemulsification and Trabectome outcomes

BACKGROUND

In this retrospective comparative cohort outcome study, the influence of Selective Laser Trabeculoplasty (SLT) on combined clear cornea phacoemulsification and ab interno trabeculectomy (Trabectome) outcomes in Primary Open Angle Glaucoma (POAG), Pseudoexfoliation Glaucoma (PEX), and Pigmentary Glaucoma (PG) was examined.

METHODS

Combined clear cornea phacoemulsification and Trabectome were performed in 27 consecutive patients with POAG, in 27 patients with PEX, and in 20 patients with PG. Each group was divided into two subgroups including patients without SLT treatment prior to surgery and patients who had insufficient response to 360° SLT treatment three months prior to surgery.

RESULTS

In the SLT group, mean IOP at six months measured 13.33 ± 2.08 mmHg with an average decrease of 30 % from preoperative IOP in the POAG group, 12.10 ± 1.40 mmHg with an average decrease of 46 % in the PEX group, and 11.83 ± 2.21 mmHg with an average decrease of 38 % in the PG group. In eyes without previous SLT, mean IOP sixt 6 months measured 11.00 ± 1.73 mmHg with an average decrease of 38 % from preoperative IOP in the POAG group, 15.50 ± 1.41 mmHg with an average decrease of 35 % in the PEX group, and 15.67 ± 2.91 mmHg with an average decrease of 36 % in the PG group, respectively.

CONCLUSIONS

Prior SLT treatment seems not to negatively influence combined clear cornea phacoemulsification and Trabectome outcomes in glaucoma patients. However, SLT treatment may even have an additive effect on following combined Trabectome outcomes in patients with PEX and PG.

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 following failed combined phacoemulsification cataract extraction and ab interno trabeculectomy

PURPOSE

To assess the effect of selective laser trabeculoplasty (SLT) following failed phacoemulsification cataract extraction combined with ab interno trabeculectomy (AIT) using the Trabectome (phaco-trabectome).

DESIGN

Randomized, interventional case series.

METHODS

Retrospectively, the medical records of patients who underwent SLT between March 2010 and July 2012 by 1 surgeon at a single center after a failed phaco-AIT were evaluated. Inclusion criteria were age ≥18 years with no upper limit and prior failed phaco-AIT attributable to glaucoma progression. Exclusion criterion was performance of any additional glaucoma procedure with influence on intraocular pressure (IOP) during follow-up and a follow-up after surgery of <3 months. Success was defined by reduction of IOP of >3 mm Hg and 20% and number of antiglaucoma medications equal to or less than baseline. Main outcome measures were IOP, antiglaucoma medications, time to failure, and Kaplan-Meier survival curve.

RESULTS

Fourteen eyes of 13 subjects were included. Mean follow-up after SLT was 12.9 ± 8.7 months. Total laser energy was 59.5 ± 8.7 mJ. Baseline IOP was 17.9 ± 3.3 mm Hg and number of antiglaucoma medications at baseline was 2.0 ± 1.0. All SLT procedures failed. Median time to failure after SLT was 3.6 ± 0.8 (range 2.1-5.1) months. Number of antiglaucoma medications did not change.

CONCLUSIONS

In eyes in which the IOP was no longer controlled following phaco-trabectome, SLT had a limited duration of significant IOP-lowering effect. Other alternatives, such as incisional filtration surgery, should be considered following failed phaco-trabectome.

Corneal changes after a single session of selective laser trabeculoplasty for open-angle glaucoma

PURPOSE

To investigate the changes in endothelial cell count, central corneal thickness (CCT), and refractive error after a session of selective laser trabeculoplasty (SLT) for open angle glaucoma (OAG).

METHODS

This prospective cohort study recruited 111 eyes of 66 consecutive subjects with OAG. Subjects received SLT to 360° of the trabecular meshwork. Endothelial cell count, CCT, and spherical equivalent were measured at baseline before SLT as well as at 1 week and 1 month post SLT. A repeated measure nested ANOVA with Tukey's multiple comparison test was performed to compare the outcome measures before and after SLT.

RESULTS

In 111 eyes of 66 subjects, the mean number of laser applications per treatment was 166.9 ± 41.4 with a mean energy level of 1.0 ± 0.07 mJ. The mean endothelial cell count decreased significantly from 2465.0 ± 334.0 cells/mm(2) at baseline to 2355.0 ± 387.0 cells/mm(2) at 1 week (P=0.0004) but increased to baseline levels at 1 month post SLT (2424.0 ± 379.4 cells/mm(2), P=0.3). The CCT, which decreased from a baseline of 549.4 ± 37.6 to 543.9 ± 40.2 μm at 1 week post SLT (P=0.02), also returned to the baseline level by 1 month (P=0.2). The spherical equivalent was static from baseline. A positive correlation was found between total laser energy and CCT at 1 month post treatment (r=0.3, P=0.005).

CONCLUSION

The transient reductions in endothelial cell count and CCT following SLT returned to baseline levels 1 month after the procedure. Patients undergoing SLT should be aware of the risk of potential corneal changes.

Selective laser trabeculoplasty success in pediatric patients with glaucoma: two case reports

Introduction

Selective laser trabeculoplasty is a treatment option to lower intraocular pressure in patients with glaucoma. It has been proven to work in adults. We describe two pediatric patients with glaucoma who responded well to selective laser trabeculoplasty.

Case presentations

Two patients with pediatric glaucoma underwent selective laser trabeculoplasty. Patient 1 was a nine-year-old Iranian Asian girl with secondary aphakic glaucoma who was taking four glaucoma medications. She had a 50% decrease in intraocular pressure five weeks after selective laser trabeculoplasty. She was able to discontinue all four glaucoma drops after treatment. Patient 2 was a 13-year-old Filipino Caucasian boy who presented with early juvenile open-angle glaucoma and who was on no medications. He had a 40% drop in intraocular pressure four weeks after selective laser trabeculoplasty.

Conclusion

Selective laser trabeculoplasty can decrease intraocular pressure in pediatric patients with glaucoma, both as a primary and secondary therapy. This study demonstrates that selective laser trabeculoplasty is a good option for the treatment of glaucoma in the pediatric population.

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.

Mid-term evaluation of the new Glaukos iStent with phacoemulsification in coexistent open-angle glaucoma or ocular hypertension and cataract

AIMS

To evaluate the mid-term efficacy and safety of the GTS-400-iStent combined with phacoemulsification in patients with cataract and open-angle glaucoma (OAG) or ocular hypertension (OHT).

METHODS

Prospective, non-comparative, uncontrolled, interventional case series study. Subjects underwent phacoemulsification and two GTS-400 implantation. Efficacy outcomes: intraocular pressure (IOP) and antiglaucoma medications. Safety outcomes: complications, best-corrected visual acuity and endothelial cell count (ECC). Follow-up was 1 year.

RESULTS

20 patients were enrolled (mean age: 75.1 ± 8.6 years). Mean medicated baseline IOP was 19.95 ± 3.71 mm Hg and 26 ± 3.11 mm Hg without medication. Mean final IOP was 16.75 ± 2.24, determining a final IOP decrease of 35.68% (9.42 ± 3 mm Hg; p<0.001), from baseline washout IOP. Mean number of medications fell from 1.3 ± 0.66 to 0.3 ± 0.57 (P<0.001). 75% of patients were off medications at one year. Mean ECC decreased from 2289.64 ± 393.5 cells/mm(2) to 1986.95 ± 520.58 cells/mm(2).

CONCLUSIONS

Combined cataract surgery with implantation of GTS-400-iStent seems to be an effective and safe procedure.