Micropulse laser for the treatment of glaucoma: A literature review

Noninferiority of selective and micropulse laser trabeculoplasties: a meta-analysis and systematic review

Chronic open-angle glaucoma (COAG) affecting over 70 million people globally, is one of the leading causes of irreversible blindness. To lower intraocular pressure (IOP) in COAG, common treatments include Selective Laser Trabeculoplasty (SLT) and Micropulse Laser Trabeculoplasty (MLT). This systematic review and meta-analysis evaluates the efficacy, safety, and clinical outcomes of both treatments in managing open-angle glaucoma. A systematic review and meta-analysis following PRISMA guidelines, with searches across MEDLINE, EMBASE, EMCARE, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to July 2024. Five studies, including 462 eyes from COAG patients, met the inclusion criteria. Primary outcomes were the success rate (defined as ≥ 20% IOP reduction) and mean IOP reduction. Secondary outcomes included adverse events, medication use, and requirement for glaucoma surgery. No significant difference was observed between both treatments in success rates (OR = 0.91, 95% CI: 0.61-1.36, P = 0.64). Mean IOP reduction at 3-6 months (MD = 0.46 mmHg, 95% CI: -0.43-1.36, P = 0.31) and 6-12 months (MD = 0.72 mmHg, 95% CI: -0.22-1.65, P = 0.13) showed no significant differences. Medication requirements, post-laser IOP spikes, and requirement for further surgery were similar between both treatments (OR = 2.31, 95% CI: 0.75-7.15, P = 0.15). SLT and MLT are both effective and safe for COAG, showing no significant differences in efficacy or safety over one year. MLT's cooling cycles may reduce IOP spikes, but further studies are needed to confirm long-term outcomes. Clinicians can choose between treatments based on patient-specific preferences and needs.

Long-Term Treatment Outcomes of Micropulse Transscleral Cyclophotocoagulation in Primary and Secondary Glaucoma: A 5-Year Analysis

INTRODUCTION

To investigate 5-year outcomes on intraocular pressure (IOP) and safety of micropulse transscleral cyclophotocoagulation (TSCPC) in patients with glaucoma.

METHODS

Patients with mild to advanced glaucoma who underwent a standardized micropulse TSCPC procedure at the University Eye Clinic Maastricht from November 2016 to February 2019 were included.

RESULTS

A total of 165 eyes were included, with outcomes for 112 eyes available after 5-year follow-up. Mean age was 67.3 ± 13.9 years; 58.2% were male. Glaucoma subtypes were primary glaucoma (n = 108) and secondary glaucoma (n = 57). Prior glaucoma surgery was performed in 65 of 165 eyes (39.4%). In the primary glaucoma group, mean preoperative IOP was 20.7 ± 7.1 mmHg. Mean postoperative IOP at 1, 2, 3, 4, and 5 years significantly reduced to 15.2 ± 6.5, 14.3 ± 5.0, 14.0 ± 4.9, 13.5 ± 4.1, and 12.9 ± 4.3 mmHg, respectively. Preoperatively, the mean number of IOP-lowering medications was 3.3 ± 1.3, which changed to 2.8 ± 1.3, 2.8 ± 1.2, 2.8 ± 1.2, 2.9 ± 1.2, and 2.7 ± 1.3 at 1, 2, 3, 4, and 5 years, respectively. In the secondary glaucoma group, mean preoperative IOP was 28.7 ± 10.3 mmHg, dropping significantly to 19.3 ± 10.4, 18.6 ± 11.3, 17.8 ± 9.8, 18.1 ± 12.0, and 15.5 ± 7.6 mmHg at the same intervals. The number of IOP-lowering medication was significantly reduced from 3.5 ± 1.1 to 2.5 ± 1.5, 2.2 ± 1.5, 2.6 ± 1.4, 2.6 ± 1.5, and 2.5 ± 1.7. In the total group, mean IOP reduction was 32.5% after 5 years. Postoperative complications included cystic macular edema (n = 3), fibrinous/uveitic reaction (n = 1), and rejection of corneal graft (n = 2), all reversible after treatment. One patient developed late and persisting hypotony. Other adverse events were retinal venous occlusion (n = 1) and retinal vasculitis (n = 1), unrelated to the laser treatment. In patients with a preoperative Central Distance Visual Acuity (CDVA) > 0.05 on the Snellen chart, more than two lines of visual acuity (VA) loss were attributed to cataract (n = 10), retinal disease (n = 5), glaucoma progression (n = 3), corneal decompensation (n = 2), or other factors (n = 11).

CONCLUSION

Micropulse TSCPC is a safe and effective treatment for reducing IOP and the number of IOP-lowering medications after a 5-year follow-up period. It is a viable alternative for patients after failed incisional glaucoma surgery or high-risk patients.

A Systematic Review of Micropulse Laser Trabeculoplasty (MLT) in Primary Open-Angle Glaucoma (POAG) Management: Efficacy, Safety, and Future Perspectives

BACKGROUND/OBJECTIVES

Micropulse laser trabeculoplasty (MLT) is gaining attention as a non-invasive treatment option for primary open-angle glaucoma (POAG), offering an alternative to traditional surgeries and medications. This systematic review evaluates the effectiveness, safety, and potential of MLT in glaucoma management.

METHODS

This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The strength of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, following the 2011 Oxford Centre for Evidence-Based Medicine (OCEBM) recommendations.

RESULTS

We identified 79 articles, and after removing duplicates and screening abstracts, 56 articles were eligible for further review. A detailed full-text analysis was conducted on 26 articles, of which 15 met the predefined inclusion criteria.

CONCLUSIONS

MLT shows promise as a primary or adjunctive treatment for reducing intraocular pressure (IOP) in glaucoma and ocular hypertension patients. Current evidence supports its efficacy and safety; however, additional long-term studies are needed to confirm its durability and compare its effectiveness with traditional surgical and pharmacological approaches. Standardizing treatment protocols and refining patient selection criteria could enhance MLT's clinical value and support its broader adoption in glaucoma care.

[Glaucoma surgeries: Long-term results - A review]

The surgical treatment of glaucoma has been and is still based on filtering surgeries, commonly used for about half a century. The safety and efficacy of these techniques have been well described, as it has also been done for cyclophotocoagulation and valves or tubes, indicated in France mostly for refractory glaucoma. Minimally invasive glaucoma surgeries have emerged in recent decades, increasing the number of therapeutic options, and allowing treatment decisions to be as patient-centered as possible. Most of these techniques have now been studied for more than five years. Since glaucoma is a chronic, progressive optic neuropathy, the sustainability of each surgery's results is essential. The amount of available data concerning long-term efficacy and safety of glaucoma surgeries is increasing, so we have decided to describe it through this review of the literature.

Outcomes of MicroPulse® Transscleral Laser Therapy Using the Revised MicroPulse P3® Delivery Device

Aims and background

To evaluate the safety and efficacy of MicroPulse® transscleral laser therapy (MP-TLT) using the revised MicroPulse P3® (MP3) probe compared to the original probe.

Materials and methods

A retrospective study of 122 consecutive eyes of 99 glaucoma patients who received MP-TLT with a minimum of 12 months follow-up. The primary outcome was success at 12 months, defined as final IOP <18 mm Hg and either IOP reduction of >20% or any medication reduction, without any adverse events or secondary surgical interventions (SSIs) within 12 months.

Results

Ninety-five eyes in 75 patients were treated with the original probe, and 27 eyes of 24 patients were treated with the revised probe. The mean total energy and fluence used were 113.6 joules (J) and 54.3 J/cm2 for the original probe, and 79.9 J and 140.1 J/cm2 for the revised probe. Subjects were mostly white with primary open-angle glaucoma and a mean age of 70.3 years. Significantly more eyes with advanced glaucoma were treated with the revised probe compared to the original probe (p < 0.001). At baseline, mean IOP was 23.0 ± 7.5 on 2.94 ± 1.19 medications for the original probe compared to 22.6 ± 6.9 (p = 0.799) on 3.15 ± 1.32 medications (p = 0.429) for the revised probe. At 12 months, mean IOP was 17.9 ± 5.9 mm Hg (21.4% reduction) on 2.55 ± 1.40 medications (13.0% reduction) for the original probe compared to 14.8 ± 5.7 mm Hg (29.7% reduction, p = 0.063) on 3.07 ± 1.49 medications (2.2% reduction, p = 0.279) for the revised probe. Thirty-one of 95 eyes (32.6%) and 11 of 27 eyes (40.7%) treated with original and revised MP-TLT, respectively, achieved success at 12 months (p = 0.435). The rate of SSIs was 12% and similar between groups (p = 0.833). Significantly more eyes treated with the original probe underwent repeat MP-TLT within 12 months (44.2 vs 22.2%, p = 0.049). No adverse events occurred in either group.

Conclusion and clinical significance

The revised probe for the MP3 device may result in an improved and longer-lasting IOP-lowering effect compared to the original probe, while maintaining an excellent safety profile.

How to cite this article

Ramachandran M, Voss J, Ferrell J, et al. Outcomes of MicroPulse® Transscleral Laser Therapy Using the Revised MicroPulse P3® Delivery Device. J Curr Glaucoma Pract 2024;18(4):147-154.

Phakia and Prior Incisional Surgery Impact MicroPulse Transscleral Laser Therapy for Glaucoma Outcomes: A Retrospective Cohort Study

Purpose

To assess (1) safety and efficacy of MicroPulse transscleral laser therapy (TLT) for primary open-angle glaucoma (POAG) and (2) the influence of prior incisional glaucoma surgery, lens status, and visual acuity on TLT outcomes.

Setting

Institutional.

Design

Retrospective cohort study.

Materials and methods

Study population: Included were POAG patients aged 18-85 with TLT between 1st January 2020 and 15th July 2023; excluded were patients with secondary glaucomas, inflammatory disease, or pregnancy.Intervention: MicroPulse TLT was performed on one or both eyes with an Iridex Cyclo G6 Laser with settings: 31.3% duty cycle, 2,500 mW, 20 second/sweep/hemisphere, four to six sweeps. The revised MP3 probe was used.Outcome measures: Pre- and postop: intraocular pressure (IOP), best-corrected visual acuity (BCVA), glaucoma meds, subsequent procedures, cystoid macular edema (CME).Analysis: Kaplan-Meier (KM) survival statistics starting one month postop with dropout parameters: hypotony, subsequent glaucoma procedure, glaucoma medications >baseline, IOP >21 mm Hg, IOP reduction <20%, or loss of LP vision.

Results

Thirty-three eyes were included. Mean KM survival (months) was: all eyes 8.4 ± 1.1; phakia 6.2 ± 0.8; pseudophakia 10.8 ± 2.4; aphakia 9.2 ± 1.8; prior tube shunt 10.2 ± 1.8; no filtration 6.8 ± 0.8. IOP and glaucoma medications remained at or below baseline at all postoperative timepoints. There were no significant changes in BCVA for patients with good baseline vision (>20/40), and no patients developed hypotony, persistent inflammation, or lost LP vision. Factors limiting success were time from the procedure and number of sweeps.

Conclusion

Survival was better in pseudophakic eyes and after tube shunt surgery. Six sweeps resulted in higher success compared to four. There were no significant cases of postop CME. The procedure did not negatively impact vision in eyes with good baseline vision.

How to cite this article

Jones SG, Clark F, Toeteberg-Harms M. Phakia and Prior Incisional Surgery Impact MicroPulse Transscleral Laser Therapy for Glaucoma Outcomes: A Retrospective Cohort Study. J Curr Glaucoma Pract 2024;18(4):142-146.

Comparison of Efficacy of Micropulse Laser Settings for Glaucoma Management

Objectives: This study aims to compare micropulse transscleral cyclophotocoagulation (MP-TSCPC) laser parameters and determine the optimal laser setting. Methods: A retrospective study was performed on 351 eyes from patients who underwent MP-TSCPC at four power settings (1500 mW, 2000 mW, 2250 mW, and 2500 mW) from June 2018 to December 2021. The primary measurements of the efficacy of MP-TSCPC were the degree of intraocular pressure (IOP) reduction and the number of glaucoma medication reductions. The rate of hypotony was obtained to assess the safety of MP-TSCPC. Results: At 1500, 2000, and 2500 mW, the mean IOP reduction at each visit was statistically significant compared to the baseline, and at 2250 mW, the mean IOP was only significantly different at 18 months (p < 0.05). The change in the number of medications with 2000 mW has shown significance at 1 and 3 months from the baseline; with 2500 mW, statistical significance was shown at 3, 6, 12, and 18 months (p < 0.05) compared to the baseline. Mean IOP reductions (%) were greater in 2000 mW than in 1500 mW at 1 week, 1 month, and 3 months and were greater in 2500 than in 1500 mW at 1 week (p < 0.05). There was no significance for mean IOP reductions at 6, 12, and 18 months across all powers. Only two occurrences of hypotony were reported. Conclusions: MP-TSCPC at 1500 mW, 2000 mW, and 2500 mW is a safe and effective treatment for IOP reduction. MP-TSCPC at 2250 mW is safe but may show delayed effectiveness in IOP reduction. In the long term, no one specific power setting was found to be superior for IOP reduction.

Real-world outcomes of micropulse transscleral laser therapy in glaucoma patients: Efficacy of initial and repeated treatment, transient intraocular pressure spikes

Purpose

To investigate the clinical outcomes of micropulse transscleral laser therapy (MP-TLT) in a cohort of glaucoma patients, including safety profile, post-operative transient intraocular pressure (IOP) spikes, long-term efficacy and prognostic factors in terms of IOP-lowering.

Methods

This was a retrospective observational cohort study. Medical records of all patients who consecutively underwent MP-TLT between May 2019 and February 2023 at a tertiary referral centre were scrutinised and relevant data were retrospectively analysed.

Results

A total of 131 patients (138 eyes) with a mean age of 73.2 ± 14.2 years were included. Mean pre-interventional IOP was 24.1 ± 9.1 mmHg. Within 6-12 h following the intervention on the same day, an IOP spike was regularly observed, reaching on average 31.7 ± 10.3 mmHg (p < 0.001 to baseline). Two years after the intervention, mean IOP was 16.1 ± 5.6 mmHg (p < 0.005 to baseline). In 18 eyes, the treatment was repeated, and the IOP lowering effect was more durable after the second intervention compared to the first one (Cox-Mantel test, p=<0.005). Apart from the transient post-interventional IOP spikes, no severe complications were observed.

Conclusions

MP-TLT is associated with significant IOP spikes in the first post-operative hours. Thus, close post-interventional IOP monitoring or even preventive (additional) IOP-lowering treatment may be considered. In the long term, the procedure yields favourable outcomes in terms of safety and IOP reduction. Repeated MP-TLT treatment, if necessary, seems to achieve more sustained IOP reduction than the initial treatment.

Case report: Topical pilocarpine ameliorated the accommodation loss and pupillary dilation after micropulse transscleral laser treatment

BACKGROUND

The present study elucidates a common significant postoperative complication of micropulse transscleral laser treatment (mTLT) and explores its potential management strategies for younger patients with good central vision.

CASE PRESENTATION

Three younger Chinese glaucoma patients with good central vision maintained high intraocular pressures (IOPs) (36, 25, and 30 mmHg) on maximally tolerated topical anti-glaucoma medications. All patients were treated with mTLT because of a higher risk of complications with filtering surgery. After the procedure, their best-corrected visual acuities were not significantly changed, IOPs were significantly decreased, and the number of topical anti-glaucoma medicines was gradually decreased. However, all patients complained about reduced near visual acuity (NVA) for 1-5 months. Slit-lamp examination revealed pupillary dilation, and binocular accommodative function examination indicated accommodation loss. After treatment with 2% topical pilocarpine, all patients reported an improvement in NVA. Among them, we could observe pupillary constriction, recovery of accommodation function, and improved NVA, even discontinuation of pilocarpine in Patient 2.

CONCLUSION

In younger patients with good central vision, topical pilocarpine might ameliorate accommodation loss and pupillary dilation after mTLT.

Outcomes of Micropulse Laser Trabeculoplasty Compared to Selective Laser Trabeculoplasty: A Systematic Review and Meta-Analysis

Purpose

To perform a meta-analysis and systematic review to compare the efficacy and complications of micropulse laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT) in adult patients with open-angle glaucoma (OAG) and ocular hypertension (OHT).

Methods

We performed a systematic review utilizing PubMed, Embase, and Scopus, on April 8, 2024. Meta-analyses were performed for the mean change in intraocular pressure (IOP) at one-month, six-month, and one-year follow-up visits, rate of IOP spikes (>5 mmHg increase from the pre-procedure baseline IOP), rate of treatment failure (<20% or <3 mmHg reduction in IOP or requiring additional medications or procedures), and mean change in number of medications.

Results

Six studies, with a total of 593 eyes, were included: 283 underwent MLT, while 310 underwent SLT. A statistically significant difference in the efficacy of MLT versus SLT at one-month and six-month follow-ups was present, with SLT reducing IOP by 0.83 mmHg (95% CI: 0.20, 1.47; P = 0.01) more and 0.55 mmHg (95% CI: 0.02, 1.08; P = 0.04) more than MLT, respectively. At the one-year follow-up, there was no significant disparity in IOP reduction between SLT and MLT (WMD = 0.16; 95% CI: -0.40, 0.71; P = 0.58). There was a significantly lower rate of IOP spikes in the MLT treatment group (RR = 0.37; 95% CI: 0.16, 0.89; P = 0.03). There was no statistically significant difference in the rate of treatment failures (RR = 1.05; 95% CI: 0.68, 1.62; P = 0.84) or number of topical medications reduced (WMD = 0.06; 95% CI: -0.13, 0.26; P = 0.53).

Conclusion

While SLT may offer greater short-term reductions in IOP, it may be associated with more postoperative IOP spikes when compared to MLT. At one-year follow-up, there were no significant differences in IOP reduction or failure rates between the MLT and SLT groups.

Hyphema and vitreous hemorrhage after micropulse cyclophotocoagulation a case report

INTRODUCTION

We present two cases of vitreous hemorrhage after micropulse cyclophotocoagulation one of which had concurrent hyphema. To the best of our knowledge, these are the first cases of vitreous hemorrhage due to micropulse CPC in the United States.

CASE DESCRIPTION

The first case is an 82-year-old woman with bilateral severe primary open angle glaucoma. BCVA in the right eye was 20/25, and 10-2 Humphrey visual field showed severe peripheral defects. The patient underwent MPCPC of the right eye and at one week, a settled 2 mm hyphema and vitreous hemorrhage confirmed by B-scan were noted. At three months, the patient had a BCVA of 20/80 with an IOP of 12 and retina consultation deferred a PPV. The second case is of a patient with bilateral moderate stage POAG who underwent MPCPC in both eyes. His original VA was 20/200 bilaterally. At 2 weeks, RE VA was count fingers at one foot and LE was 20/150-1. At two months, a RE B scan revealed dense vitreous opacities. Retina consultation revealed vitreous hemorrhage but a PPV was deferred.

CONCLUSION

Clinicians should be aware of the risks of bleeding and the potential need for additional surgical interventions after MPCPC.

Uveoscleral Outflow Routes after MicroPulse Laser Therapy for Refractory Glaucoma: An Optical Coherence Tomography Study of the Sclera

To analyze in vivo scleral changes induced by MicroPulse transscleral laser therapy (MP-TLT) in refractory glaucoma using anterior segment-optical coherence tomography (AS-OCT). Forty-two candidate patients for MP-TLT were consecutively enrolled and underwent AS-OCT at baseline and after six months. MP-TLT success was defined as an intraocular pressure (IOP) reduction by one-third. The main outcome measures were the mean superior (S-), inferior (I-), and total (T-) intra-scleral hypo-reflective space area (MISHA: mm2) and scleral reflectivity (S-SR, I-SR, T-SR; arbitrary scale) as in vivo biomarkers of uveoscleral aqueous humor (AH) outflow. The IOP was the secondary outcome. The relations between the baseline-to-six months differences (D) of DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, DT-SR, and DIOP, were investigated. At 6 months, the median IOP reduction was 21% in the failures and 38% in the successes. The baseline S-MISHA, I-MISHA, and T-MISHA did not differ between the groups, while S-SR and T-SR were higher in the successes (p < 0.05). At six months, successful and failed MP-TLTs showed a 50% increase in S-MISHA (p < 0.001; p = 0.037), whereas I-SR and T-SR reduced only in the successes (p = 0.002; p = 0.001). When comparing DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, and DT-SR, there were no significant differences between the groups. In the successful procedures, DIOP was positively correlated with DT-MISHA and DI-MISHA (ρ = 0.438 and ρ = 0.490; p < 0.05). MP-TLT produced potentially advantageous modifications of the sclera in refractory glaucoma. Given the partial correlation between these modifications and post-treatment IOP reduction, our study confirmed that the activation of the uveoscleral AH outflow route could significantly contribute to the IOP lowering after MP-TLT.

Mechanism and treatment of secondary glaucoma after corneal transplantation: a review

Corneal transplantation is a common treatment for corneal diseases. Secondary glaucoma after corneal transplantation is the second leading cause of failure of keratoplasty. This article reviews the mechanism and treatment of secondary glaucoma after corneal transplantation.

Subthreshold micropulse laser therapy for early postoperative macular thickening following surgical removal of epiretinal membrane

BACKGROUND

This study aimed to investigate the functional and anatomical outcomes of subthreshold micropulse laser (SMPL) therapy in eyes with early postoperative macular thickening after idiopathic epiretinal membrane (iERM) removal.

METHODS

This was a prospective and interventional study. Forty-eight eyes from 48 patients with macular edema at 1 month after iERM removal were randomly divided into two groups. Patients in the SMPL group (n = 24) received SMPL therapy while no special intervention was used for the observation group (n = 24). Baseline demographic data and clinical findings before and at 1 and 3 months after SMPL treatment or observation, including best-corrected visual acuity (BCVA) and the changes in central subfield thickness (CST) and average macular thickness (AMT), were analyzed.

RESULTS

An improvement in BCVA with a decrease in CST and AMT from baseline to the 3-month follow-ups were observed in both SMPL and observation groups. No significant difference in BCVA was observed between the SMPL group and observation group either in the 1-month (0.26 [0.15, 0.52] vs. 0.26 [0.15, 0.39], P = 0.852) or the 3-month (0.15 [0.10, 0.30] vs. 0.23 [0.15, 0.30], P = 0.329) follow-up. There was a greater reduction in CST in the SMPL group versus observation group between baseline and the 3-month follow-up (-77.8 ± 72.3 μm vs. -45.0 ± 46.9 μm, P = 0.049). The alteration in AMT did not differ between the two groups in either 1-month (-16.5 ± 20.1 μm vs. -19.7 ± 16.3 μm, P = 0.547) or 3-month (-36.9 ± 26.9 μm vs. -34.0 ± 20.1 μm, P = 0.678) follow-up.

CONCLUSIONS

SMPL therapy led to a significant decrease in CST at the 3-month follow-up while did not significantly improve the visual acuity in patients with postoperative macular thickening following iERM surgery.

TRIAL REGISTRATION

The study was registered on Aug 27, 2020 (Trial Registration Number: ChiCTR 2000037227).

Micropulse cyclophotocoagulation compared to continuous wave cyclophotocoagulation for the management of refractory pediatric glaucoma

INTRODUCTION

Micropulse cyclophotocoagulation (MPCPC) has been shown in adults to offer a favorable post-operative safety profile compared to continuous wave transscleral cyclophotocoagulation (CWCPC) in the management of glaucoma. The purpose of this study is to evaluate the long term efficacy, safety, and effectiveness of MPCPC in the management of pediatric glaucoma when compared to CWCPC.

METHODS

IRB approved retrospective chart review of patients with pediatric glaucoma that underwent MPCPC and CWCPC at 2 separate institutions. Success was defined as intraocular pressure (IOP) between 5 and 21mmHg on any number of topical glaucoma medication without requiring additional surgical intervention or oral IOP lowering medication.

RESULTS

Of the 48 patients in the study, 22 (26 eyes) underwent MPCPC and 26 (30 eyes) underwent CWCPC. At 1 year, 7 out of 26 eyes (26.9%) achieved success in the MPCPC group compared to 13 out of 30 eyes (43.3%) in the CWCPC group. Survival analysis unveiled a statistically significant difference in success between the two groups (p = 0.03).

CONCLUSION

In pediatric glaucoma patients undergoing cyclophotocoagulation procedures, CWCPC outperformed MPCPC using default settings in terms of achieving long-term IOP control. Additional studies are required to evaluated augmented MPCPC settings in pediatric glaucoma patients.

Alternatives to Topical Glaucoma Medication for Glaucoma Management

Topical glaucoma medications have favorable safety and efficacy, but their use is limited by factors such as side effects, nonadherence, costs, ocular surface disease, intraocular pressure fluctuations, diminished quality of life, and the inherent difficulty of penetrating the corneal surface. Although traditionally these limitations have been accepted as an inevitable part of glaucoma treatment, a rapidly-evolving arena of minimally invasive surgical and laser interventions has initiated the beginnings of a reevaluation of the glaucoma treatment paradigm. This reevaluation encompasses an overall shift away from the reactive, topical-medication-first default and a shift toward earlier intervention with laser or surgical therapies such as selective laser trabeculoplasty, sustained-release drug delivery, and micro-invasive glaucoma surgery. Aside from favorable safety, these interventions may have clinically important attributes such as consistent IOP control, cost-effectiveness, independence from patient adherence, prevention of disease progression, and improved quality of life.

Tongqiao Mingmu formula alleviates retinal ganglion cell autophagy through PI3K/AKT/mTOR pathway

Glaucoma is a severe blindness-causing optic nerve disease characterized by a loss of retinal ganglion cells (RGCs). Previous studies have shown that the Tongqiao Mingmu (TQMM) formula can reduce retinal and optic nerve damage, but its mechanism of action requires further elucidation. In this study, an RGC injury model was prepared using glutamate and then treated with serum-containing drug from the TQMM formula (hereafter called "TQMM formula serum"). In the glutamate-induced RGC injury model, cell viability decreased with an increase in glutamate concentration, whereas the expression of autophagy-related biomarkers LC3 and Belicin-1 increased. An adenovirus transfection experiment revealed that glutamate markedly promoted autophagic flux in RGCs. Notably, TQMM formula serum inhibited the expression of autophagy-related biomarkers, reduced autophagy flux, and reversed the damage caused by glutamate to RGCs. Furthermore, the PI3K inhibitor LY294002 was used to intervene in the RGC autophagy model and was found to suppress the PI3K/AKT/mTOR pathway and enhance RGC autophagy. However, TQMM formula serum could generate an opposite effect and upregulate the expressions of the PI3K/AKT/mTOR pathway genes and proteins. In conclusion, the TQMM formula can prevent glutamate-induced autophagy in RGCs, possibly by activating the PI3K/AKT/mTOR pathway and reducing the expression of autophagy-related biomarkers LC3 and Belicin-1 to attenuate autophagy and maintain RGC viability.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Cyclophotocoagulation as a Minimally Invasive Treatment Option for Glaucoma

Historically, the complications and inadequate efficacy of prior cyclodestructive procedures limited their role in glaucoma management. Recent advances in treatment techniques and parameters for laser cyclophotocoagulation has expanded its role in today's glaucoma practice. This review summarizes the role of different cyclophotocoagulation techniques, including continuous wave transscleral cyclophotocoagulation and micropulse transscleral cyclophotocoagulation, in the management of glaucomatous optic neuropathy.

The correlation between primary open-angle glaucoma (POAG) and gut microbiota: a pilot study towards predictive, preventive, and personalized medicine

Background

Glaucoma is the leading cause of irreversible blindness worldwide. Emerged evidence has shown that glaucoma is considered an immune system related disorder. The gut is the largest immune organ in the human body and the gut microbiota (GM) plays an irreversible role in maintaining immune homeostasis. But, how the GM influences glaucoma remains unrevealed. This study aimed at investigating the key molecules/pathways mediating the GM and the glaucoma to provide new biomarkers for future predictive, preventive, and personalized medicine.

Methods

Datasets from the primary open-angle glaucoma (POAG) patients (GSE138125) and datasets for target genes of GM/GM metabolites were downloaded from a public database. For GSE138125, the differentially expressed genes (DEGs) between healthy and POAG samples were identified. And the online Venn diagram tool was used to obtain the DEGs from POAG related to GM. After which GM-related DEGs were analyzed by correlation analysis, pathway enrichment analysis, and protein-protein interaction (PPI) network analysis. Human trabecular meshwork cells were used for validation, and the mRNA level of hub genes was verified by quantitative real-time polymerase chain reaction (RT-qPCR) in the in vitro glaucoma model.

Results

A total of 16 GM-related DEGs in POAG were identified from the above 2 datasets (9 upregulated genes and 7 downregulated genes). Pathway enrichment analysis indicated that these genes are mostly enriched in immune regulation especially macrophages-related pathways. Then 6 hub genes were identified by PPI network analysis and construction of key modules. Finally, RT-qPCR confirmed that the expression of the hub genes in the in vitro glaucoma model was consistent with the results of bioinformatics analysis of the mRNA chip.

Conclusion

This bioinformatic study elucidates NFKB1, IL18, KITLG, TLR9, FKBP2, and HDAC4 as hub genes for POAG and GM regulation. Immune response modulated by macrophages plays an important role in POAG and may be potential targets for future predictive, preventive, and personalized diagnosis and treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00336-2.

Exploring New Therapeutic Avenues for Ophthalmic Disorders: Glaucoma-Related Molecular Docking Evaluation and Bibliometric Analysis for Improved Management of Ocular Diseases

Ophthalmic disorders consist of a broad spectrum of ailments that impact the structures and functions of the eye. Due to the crucial function of the retina in the vision process, the management of eye ailments is of the utmost importance, but several unmet needs have been identified in terms of the outcome measures in clinical trials, more proven minimally invasive glaucoma surgery, and a lack of comprehensive bibliometric assessments, among others. The current evaluation seeks to fulfill several of these unmet needs via a dual approach consisting of a molecular docking analysis based on the potential of ripasudil and fasudil to inhibit Rho-associated protein kinases (ROCKs), virtual screening of ligands, and pharmacokinetic predictions, emphasizing the identification of new compounds potentially active in the management of glaucoma, and a comprehensive bibliometric analysis of the most recent publications indexed in the Web of Science evaluating the management of several of the most common eye conditions. This method resulted in the finding of ligands (i.e., ZINC000000022706 with the most elevated binding potential for ROCK1 and ZINC000034800307 in the case of ROCK2) that are not presently utilized in any therapeutic regimen but may represent a future option to be successfully applied in the therapeutic scheme of glaucoma following further comprehensive testing validations. In addition, this research also analyzed multiple papers listed in the Web of Science collection of databases via the VOSviewer application to deliver, through descriptive analysis of the results, an in-depth overview of publications contributing to the present level of comprehension in therapeutic approaches to ocular diseases in terms of scientific impact, citation analyses, most productive authors, journals, and countries, as well as collaborative networks. Based on the molecular docking study's preliminary findings, the most promising candidates must be thoroughly studied to determine their efficacy and risk profiles. Bibliometric analysis may also help researchers set targets to improve ocular disease outcomes.

The efficacy and safety of micropulse transscleral laser treatment in glaucoma: a systematic review and meta-analysis

OBJECTIVE

Micropulse transscleral laser treatment (mTLT) is the latest alternative intraocular pressure (IOP) lowering approach for glaucoma patients. This meta-analysis aims to evaluate the efficacy and safety of mTLT and continuous wave transscleral cyclophotocoagulation (CW-TSCPC) for the treatment of glaucoma.

METHODS

We searched the PubMed, Embase, and Cochrane Library of Systematic Reviews databases from January 2000 to July 2022 to identify studies that, evaluated the efficacy and safety of mTLT in glaucoma. There were no restrictions regarding study type, patient age, or type of glaucoma. We analysed the reduction in IOP and the number of anti-glaucoma medications (NOAM), retreatment rates, and complications between mTLT and CW-TSCPC treatment. Publication bias was conducted for evaluating bias. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2020) reporting guideline.

RESULTS

We identified 6 eligible studies of which only 2 RCTs and 386 participants with various types of glaucoma at different stages were ultimately included. The results revealed significant IOP decreases after mTLT up to 12 months and significant NOAM reductions at 1 month (WMD=-0.30, 95% CI -0.54 to 0.06), and 3 months (WMD=-0.39, 95% CI -0.64 to 0.14) in mTLT compared to CW-TSCPC. Moreover, the retreatment rates (Log OR=-1.00, 95% CI -1.71 to -0.28), hypotony (Log OR=-1.21, 95% CI -2.26 to -0.16), prolonged inflammation or uveitis (Log OR=-1.63, 95% CI -2.85 to -0.41), and worsening of visual acuity (Log OR=-1.13, 95% CI -2.19 to 0.06) occurred less frequently after mTLT.

CONCLUSION

Our results demonstrated that mTLT could lower the IOP until 12 months after treatment. mTLT seems to have a lower risk of retreatment after the first procedure, and mTLT is superior to CW-TSCPC with respect to safety. Studies with longer follow-up durations and larger sample sizes are necessary in the future.

TRIAL REGISTRATION NUMBER

INPLASY202290120.

MicroPulse Transscleral Laser Therapy Dosimetry Utilizing the Revised P3 Delivery Device: A Randomized Controlled Trial

PURPOSE

To compare the long-term effectiveness and safety outcomes of 2 treatment dosages of the MicroPulse Transscleral Laser Therapy (MPTLT) procedure on intraocular pressure (IOP) control in patients with primary open-angle glaucoma.

DESIGN

Single-blinded randomized controlled trial.

SUBJECTS

A total of 19 patients with POAG without prior history of incisional glaucoma surgery.

METHODS

Subjects randomized into 2 treatment groups, 100-second (total energy 78.25 joules [J], fluence 109.2 J/cm²) or 120-second (total energy 93.9 J, fluence 131.0 J/cm²) total treatment duration, underwent the MPTLT procedure with the revised P3 delivery probe delivering 2.5 W energy, 31.3% duty cycle, applied in 3 sweeps per hemisphere, avoiding 3 and 9 o'clock. All subjects were followed at 1, 3, 6, 9, and 12 months to compare reduction in IOP and medication.

MAIN OUTCOME MEASURES

Absolute and percentage IOP reduction at 6 months.

RESULTS

The treatment groups were similar in age, sex, and stage of glaucoma at baseline (all P > 0.05). The 120-second group had significantly better baseline best-corrected visual acuity (BCVA) and a higher percentage of patients with prior MPTLT therapy (ranging from 4-19 months before study). Significantly greater IOP reduction was noted in the 120-second group compared with the 100-second group at 3 months, with mean IOP reduction of 7.3 ± 4.2 mmHg (vs. 0.9 ± 2.5 mmHg, P = 0.006) and percentage IOP reduction of 32.2% ± 18.3% (vs. 4.1% ± 13.7%, P = 0.007). The 120-second group continued to outperform at 6-month follow-up: mean IOP reduction of 9.0 ± 4.8 mmHg (vs. 0.8 ± 2.5 mmHg, P = 0.016) and percentage IOP reduction of 37.8% ± 19.8% (vs. 3.6% ± 13.3%, P = 0.021). At 12 months, 37.5% and 18.2% of the 100- and 120-second groups, respectively, required an additional IOP-lowering procedure (P = 0.35); however, Kaplan-Meier analysis of time to intervention was not significantly different (P = 0.38). There were no vision-threatening complications or changes in BCVA during the study period.

CONCLUSIONS

This study demonstrates a dose-response relationship with improved IOP control and excellent safety profile in patients treated with higher treatment total energy and fluence using the revised MPTLT probe.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Selective laser trabeculoplasty versus micropulse laser trabeculoplasty for intraocular pressure control in patients with primary open angle glaucoma: a 12-month retrospective comparative study

This study was designed to compare the efficacy of selective laser trabeculoplasty (SLT) and micropulse laser trabeculoplasty (MLT) in patients with primary open angle glaucoma (POAG) requiring additional IOP control. In this retrospective, comparative study, we reviewed the charts of POAG patients requiring additional IOP lowering, who underwent either SLT or MLT and were followed for at least one year. We evaluated mean intraocular pressure (IOP), mean IOP reduction from baseline and mean number of glaucoma medications 1, 3, 6 and 12 months after treatment. Success rates (success defined as IOP ≤ 21 mmHg and ≥ 20% reduction from baseline IOP without additional medications, new laser session, or glaucoma surgery) at one year were also compared. A total of 98 POAG patients were included, 52 individuals in the SLT group and 46 in the MLT group. Laser treatment resulted in significant mean IOP reductions from baseline in both groups (SLT = -6.0 ± 3.3 mmHg (24.9%) and MLT = -5.8 ± 2.6 mmHg (23.4%)) (p < 0.001). However, there was no statistically significant difference between the mean IOP reductions in both groups (p = 0.74). At 12 months, the mean number of glaucoma medications was significantly smaller in the SLT group (1.17 + 0.4) when compared to the MLT group (2.21 + 0.2) (p = 0.001). Additionally, after 12 months, success was obtained in 32 (61.5%) SLT cases compared to 27 (58.7%) MLT-treated eyes (p = 1.0). MLT and SLT are both effective in controlling the IOP in POAG patients requiring additional IOP reduction. However, after 12 months, SLT demonstrated a greater efficacy in reducing medication burden when compared to MLT.Trial registration: CEP/CONEP/MS Brazil 40948620.9.0000.5600.

Micropulse Laser Trabeculoplasty with 577 nm Wavelength at 1500 or 1000 mW for Primary Open-Angle Glaucoma: A Pilot Study

Aim: To investigate the efficacy and safety of micropulse laser trabeculoplasty (MLT) using a 577 nm yellow wavelength laser randomly assigned to either 1500 or 1000 mW in patients with primary open-angle glaucoma (POAG). Methods: A prospective, double-blinded study of POAG patients was performed in a single center. MLT treatment included a 577 nm micropulse laser (IRIDEX IQ 577^TM, IRIDEX, Mountain View, CA, USA) to 360° of the trabecular meshwork at randomly assigned varying powers: 1500 mW in one eye (MLT 1500 group) and 1000 mW in the other (MLT 1000 group). Best-corrected visual acuity (BCVA), intraocular pressure (IOP), corneal central thickness (CCT), and endothelial cell count (ECC) were evaluated at baseline (T0), post-operative 1 h (T1), 24 h (T2), 1 month (T3), 3 months (T4), and 6 months (T5) after laser treatment. Topical medications were assessed pre-treatment and at T4. Results: Among the 18 eyes included, we achieved a success rate (IOP reduced > 20%) in 77% of sampled eyes. In particular, IOP reduced at T2 and T3 with both MLT 1500 and 1000 without any significant differences (IOP reduction 22.9% vs. 17.3%, respectively, MLT1500 vs. MLT1000 at T2). The IOP returned to baseline values at T4 and T5 in both groups, with a reduction in topical medications administered from 2.5 ± 1.1 to 2.0 ± 1.2 to the 1500 mW group and from 2.4 ± 1.0 to 1.9 ± 1.0 to the 1000 mW group. At 1 h post-laser treatment, a transient IOP spike was registered among the MLT1500 group. There were no differences in CCT and ECC at any timepoint according to the laser powers. Conclusions: Over a 6-month follow-up period, 577 nm MLT at either 1500 or 1000 mW reduces IOP, enabling a stable reduction in the number of topical medications required for patients treated for POAG without any significant difference in terms of effectiveness and safety.

Risk factors and management of choroidal effusions

PURPOSE OF REVIEW

Choroidal effusions are recognized as a common early postoperative complication of glaucoma surgery, and although often benign, they may cause significant ocular morbidity. This article aims to summarize current research on the risk factors and management of choroidal effusions.

RECENT FINDINGS

Glaucoma drainage device (GDD) implantation and trabeculectomy are the most commonly performed surgeries for the management of moderate to severe glaucoma. Common postoperative complications of these procedures include hypotony and the development of choroidal effusions. Choroidal effusions have recently been associated with the oral administration of certain drugs, including select monoclonal antibody, antiseizure and bisphosphonate medications. Risk factors for effusion development include specific patient characteristics such as pseudoexfoliative glaucoma, older age and hypertension. Although choroidal effusions typically resolve with medical therapy alone, surgical intervention may be required. Various methods of surgical intervention, such as surgical drainage or GDD tube ligation, can be utilized to treat choroidal effusions when conservative management with medical treatment fails, but themselves carry alternative risks that must be considered.

SUMMARY

Minimizing the incidence and duration of hypotony following ophthalmic surgery and careful monitoring of patients starting certain oral medications are important in limiting the occurrence of choroidal effusions. Risk factors for choroidal effusions have been recently identified in the literature. A better understanding of these risk factors, as well as the outcomes of choroidal effusion management, can help to reduce the occurrence of effusions overall and minimize ocular morbidity.

Micropulse diode laser therapy in refractory glaucoma

Purpose

Description of safety and efficacy of micropulse Transscleral cyclophotocoagulation as a treatment option for refractory glaucoma.

Methods

This is a prospective study including 39 eyes of 31 patients followed for refractory glaucoma, who benefited from transscleral cyclophotocoagulation using a microplused laser. The main indication for the procedure was increased ocular pressure refractory to quadritherapy in various types of glaucoma. The patients were treated using iridex Cyclo G6 laser with a Micropulse P3 infrared probe with a wavelength of 810 ​nm. The parameters for the procedure were a duration of 90 ​s per hemisphere with a power of 2000 mW and an energy of 180 ​J. Both the upper and lower hemispheres were treated in the same procedure, sparing the 3 o'clock and 9 o'clock meridians, and all the patients benefited from a single treatment session. The following parameters were evaluated: ocular pain and overall tolerance; visual acuity; and the evolution of IOP postoperatively up to 9 months.

Results

The glaucoma subtypes treated are as follows: primary open-angle glaucoma (n ​= ​05), chronic angle-closure glaucoma (n ​= ​13), neovascular glaucoma (n ​= ​07), aphakic glaucoma (n ​= ​06), malignant glaucoma (n ​= ​04), post-traumatic angle recession (n ​= ​02), and inflammatory glaucoma (n ​= ​02). The mean pre-operative intraocular pressure was 42.3 ​± ​5.2 ​mmHg and the mean post-operative intraocular pressure at 9 months was 16.9 ​± ​1.9 ​mmHg. The reduction in IOP was 49.9%. The average number of intraocular pressure-lowering medications used prior to surgery was four, and the average number of medications used at the 9-month post-operative visit was 2.0 ​± ​1.2 (70.3% of patients were on dual therapy). The overall success rate was 60.5%.

Conclusions

Micropulse transscleral cyclophotocoagulation appears to be a safe and efficient treatment for refractory glaucoma. Its indications should therefore be broadened and proposed early in various situations.

Ciliochoroidal effusion and its association with the outcomes of micropulse transscleral laser therapy in glaucoma patients: a pilot study

We investigate the development of ciliochoroidal effusion following micropulse transscleral laser therapy (MPTLT) and evaluate the relationship between the early postoperative ciliochoroidal effusion (ECE) and short-term treatment outcomes. Glaucoma patients who underwent MPTLT were assessed for ciliochoroidal effusion by anterior segment optical coherence tomography (AS-OCT) at postoperative 1, 4, 12 weeks. The subjects were classified based on AS-OCT findings at postoperative 1 week into eyes with and without ECE. The absolute intraocular pressure (IOP), IOP reduction and number of antiglaucoma medications were compared between eyes with and without ECE. A total of 50 eyes were included, of which 23 (46%) developed ciliochoroidal effusion at postoperative 1 week. Almost all effusion resolved at 4 weeks. At 12 weeks, the mean IOP (SD) significantly decreased from 28.5 (12.8) mmHg to 17.8 (10.5) mmHg (p < 0.001), and the mean number of medications (SD) decreased from 4.1 (0.9) to 3.3 (1.1) (p < 0.001). Eyes with ECE had significantly greater IOP reduction (p = 0.009) and lower absolute IOP (p = 0.008) at the 4-week visit. There was no significant difference in number of medications between the groups. In conclusion, ciliochoroidal effusion was commonly observed following MPTLT. Eyes with ECE had overall greater IOP reduction during early post-operation.

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

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

Intravitreal Injectable Hydrogels for Sustained Drug Delivery in Glaucoma Treatment and Therapy

Glaucoma is extensively treated with topical eye drops containing drugs. However, the retention time of the loaded drugs and the in vivo bioavailability of the drugs are highly influenced before reaching the targeted area sufficiently, due to physiological and anatomical barriers of the eye, such as rapid nasolacrimal drainage. Poor intraocular penetration and frequent administration may also cause ocular cytotoxicity. A novel approach to overcome these drawbacks is the use of injectable hydrogels administered intravitreously for sustained drug delivery to the target site. These injectable hydrogels are used as nanocarriers to intimately interact with specific diseased ocular tissues to increase the therapeutic efficacy and drug bioavailability of the anti-glaucomic drugs. The human eye is very delicate, and is sensitive to contact with any foreign body material. However, natural biopolymers are non-reactive, biocompatible, biodegradable, and lack immunogenic and inflammatory responses to the host whenever they are incorporated in drug delivery systems. These favorable biomaterial properties have made them widely applicable in biomedical applications, with minimal adversity. This review highlights the importance of using natural biopolymer-based intravitreal hydrogel drug delivery systems for glaucoma treatment over conventional methods.

Micropulse laser trabeculoplasty on Chinese patients with glaucoma or ocular hypertension: average 35 months follow-up results

Background

Glaucoma is a group of eye diseases that can damage the optic nerve and cause vision loss. A novel technology micropulse laser trabeculoplasty (MLT) can use duty-circle subvisible laser pulses to treat glaucoma. The aim of this study is to evaluate the efficacy of 360° MLT to alleviate intraocular pressure (IOP) in patients with glaucoma.

Methods

This was a single-center prospective study on patients treated with 360° MLT using a Diode True-Yellow 577-nm Laser with MicroPulse technology. All the patients were recruited from the Department of Ophthalmology. Follow-up visits were carried out at 1 day, 1 week, 1 month, 3 months, 6 months, 18 months, and 36 months after the procedure. Best-corrected visual acuity (BCVA), Intraocular pressure (IOP), and vertical cup-to-disc ratio (C/D ratio) were measured during the follow-up. Repeated-measures analysis of variance (ANOVA) and Kaplan–Meier analysis were performed to evaluate the outcomes.

Results

A total of 39 eyes from 25 patients were included in this study (10 men/15 women). The average age of patients was 41.47 ± 14.39 years old, and the baseline IOP was 21.13 ± 7.75 mmHg. MLT significantly reduced the IOP at 1 day (range 15.61–19.01, P = 0.0218), 3 months (range 16.47–19.22, P = 0.0390), and 6 months (range 15.38–18.56, P = 0.0332) compared with the baseline. However, by the end of the study, only 21.88% of patients demonstrated a ≥ 20% IOP reduction, while seven eyes needed further laser or surgical treatment. The IOP of glaucoma patients was significantly lower than the ocular hypertension patients at 1 month (P = 0.0124), 3 months (P = 0.0004), 18 months (P = 0.0061) and 36 months (P = 0.0119).

Conclusions

Micropulse laser trabeculoplasty reduce IOP in patients with glaucoma or ocular hypertension for a short period, but its lowering efficiency is limited up to 6 months of the follow-up period.

Comparison of Aqueous Flare Values after Micropulse Transscleral Laser Treatment and Continuous Wave Transscleral Cyclophotocoagulation

PURPOSE

The purpose of this study was to analyse the changes in flare values after Micropulse Transscleral Laser Treatment for Glaucoma (MP-TLT) in patients with refractory glaucoma and to compare with the outcomes of patients who underwent continuous wave (CW) diode laser cyclophotocoagulation (CW-TSCPC).

METHODS

In this single-centre study, we reviewed the medical records of 54 patients who underwent MP-TLT and 35 patients who underwent CW-TSCPC at Ankara University Faculty of Medicine, Department of Ophthalmology. Aqueous flare values were measured by laser flare photometry.

RESULTS

The mean laser flare values in both groups (MP-TLT/CW-TSCPC) increased after surgery from 20.85 ± 8.74/22.14 ± 7.39 ph/ms at baseline to 48.52 ± 18.23/57.38 ± 20.08 ph/ms (P = .001) on day 1 and then progressively decreased to 44.13 ± 18.32/52.24 ± 20.56 in week 1, 40.5 ± 18.5/48.24 ± 19.23 week 2 and 35.28 ± 17.09/41.11 ± 16.7 month 1 (all p < .05) and returned to similar levels to baseline at month 3 and month 6 (both p > .05). Patients who achieved treatment success had significantly higher flare values than patients who failed on post-operative day 1, week 1 and week 2 in both groups. The flare values were significantly lower in the MP-TLT group than the CW-TSCPC group on post-operative day 1, week 1, week 2 and month 1 (all p < .05). There were no cases of prolonged post-operative inflammation or serious complications in both groups.

CONCLUSION

Intraocular inflammation, quantified by aqueous flare, may be a contributing factor to the IOP lowering effect of transscleral diode laser cyclophotocoagulation in the early post-operative period.

Micropulse Transscleral Cyclophotocoagulation for Glaucoma after Penetrating Keratoplasty

The main objective of the article was to assess the surgical outcome of micropulse transscleral cyclophotocoagulation in patients presenting with glaucoma after penetrating keratoplasty. We conducted a retrospective study that included 26 eyes of 26 patients who presented with glaucoma after penetrating keratoplasty, and who were treated using micropulse transscleral cyclophotocoagulation between January 2017 and December 2020. The surgeries were performed using the Iridex Cyclo G6 MicroPulse P3 Probe. The intraocular pressure, mean number of antiglaucoma medications, visual acuity, corneal status, and postoperative complications were analyzed. The minimum follow-up period was 12 months. The success rate after 12 months was 76.9%. The baseline median intraocular pressure was 29 mm Hg and decreased to 18 mm Hg after 12 months. The median number of antiglaucoma medications was also reduced from three preoperatively to one after one year. In seven cases (29.92%), the visual acuity decreased and, in four cases (15.38%), the corneal graft was not transparent. We concluded that micropulse transscleral cyclophotocoagulation is an effective and safe method for the treatment of glaucoma after penetrating keratoplasty.

Long-term results of micropulse laser trabeculoplasty with 577-nm yellow wavelength in patients with uncontrolled primary open-angle glaucoma and pseudoexfoliation glaucoma

Our aim was to evaluate the long-term results of micropulse laser trabeculoplasty (MLT) with 577-nm yellow wavelength in the treatment of glaucoma. We reviewed the medical records of 51 patients (51 eyes) with uncontrolled primary open-angle glaucoma or pseudoexfoliation glaucoma who underwent 180° MLT for the first time. The success of MLT was defined as an IOP reduction of ≥ 20% and IOP < 21 mmHg after treatment. If the number of medications was increased or further laser trabeculoplasty or glaucoma surgery was required after treatment, the case was considered unsuccessful. The mean duration of patient follow-up was 18.39 ± 12.17 months (range 3-52 months). Patients included in the study used 2-4 types of antiglaucoma eye drops (mean 3.43 ± 0.7). The mean number of MLT spots was 65.54 ± 6.19, and the mean energy level was 750.98 ± 101.73 mJ. The decrease in intraocular pressure compared to baseline measurements was: 16.72 ± 11.87%, 15.07 ± 13.76%, 12.63 ± 14.29%, 16.66 ± 19.32%, and 16.75 ± 19.78% during follow-up at 3, 6, 12, 24, and 36-48 months. Successful response was achieved in 35.41%, 36.95%, 34.21%, 40%, 41.17%, and 42.85% of patients during 3, 6, 12, 18, 24, and 36-48 months of follow-ups, respectively. Of the 51 eyes studied, 12 patients (23.5%) underwent post-MLT glaucoma surgery, and 7 patients (13.7%) had cataract surgery, whose follow-up data were subsequently censored. The reduction of intraocular pressure showed a significant correlation with baseline intraocular pressure, while age and laser power showed no correlation (p > 0.05). MLT is a novel treatment option for patients with glaucoma with favorable long-term outcomes and a good safety profile.

Micropulse vs. continuous wave transscleral cyclophotocoagulation in neovascular glaucoma

Neovascular glaucoma (NVG) is a refractory form of glaucoma, associated with important morbidity, for which no consensus exists regarding the optimal choice of therapy. The primary aim of our study was to compare the performances of micropulse transscleral cyclophotocoagulation (MP-TSCPC) and continuous wave transscleral cyclophotocoagulation (CW-TSCPC) in the treatment of neovascular glaucoma (NVG). A total of 24 eyes for MP-TSCPC and 22 eyes for CW-TSCPC, all with NVG were included. The procedures were performed using either the Iridex Cyclo G6 (IRIDEX Laser System), the MP3, or the G-Probe devices. Intraocular pressure (IOP), visual acuity (VA), the mean number of antiglaucoma medications, and postoperative complications were monitored. The minimum follow-up was 12 months. The success rate at 12 months was 54.5% in the CW-TSCPC group and 33.3% in the MP-TSCPC group. The mean IOP at baseline was 35.82 mm Hg for CW-TSCPC and 34.71 mm Hg for MP-TSCPC. The change from baseline in IOP at 12 months was 11.95 mm Hg in the CW-TSCPC group and -8.04 mm Hg in the MP-TSCPC group. There was a significant difference in the occurrence of serious complications (worsening of VA, hypotony, and phthisis bulbi) between the two methods, with CW-TSCPC associated with more important adverse effects (P=0.045). There was a decrease in the number of topical antiglaucoma medications in both groups: in the MP-TSCPC group from a mean number of 2.6 at baseline, to 1.7 at 3 months, followed by a slight increase to 2.1 at 12 months and in the CW-TSCPC group from 2.8 at baseline, to 1.4 at 3 months and 1.9 at 12 months. Our study concluded that both MP-TSCPC and CW-TSCPC could manage NVG, but, while CW-TSCPC revealed higher IOP control in the long term (which did not reach statistical significance), it also had a significantly lower safety profile.

MicroPulse Transscleral Laser Therapy Demonstrates Similar Efficacy with a Superior and More Favorable Safety Profile Compared to Continuous-Wave Transscleral Cyclophotocoagulation

Purpose. The aim of this study was to compare effectiveness and safety of MicroPulse transscleral laser therapy (MP-TLT) using the original MicroPulse P3® device and continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) using the G-Probe® device in glaucoma. Methods. Spherical equivalent, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and number of topical or oral ophthalmic pressure-reducing medications were registered at every time point, up to the last follow-up at 12 months. A complete slit-lamp examination was conducted to record the following complications: corneal edema, persistent ocular hypotony (IOP ≤5 mmHg) on two consecutive follow-up visits, choroidal detachment, phthisis bulbi, sympathetic ophthalmia, cystoid macular edema, or other abnormal ocular findings. Success was defined as IOP between 6 and 21 mmHg and >20% reduction in IOP with or without antiglaucoma medications. Results. 47 eyes underwent MP-TLT and 150 CW-TSCPC. At 12 months, success was achieved in 88.6% in the CW-TSCPC group and 87.5% in the MP-TLT group ( $p$  = 0.883). In the CW-TSCPC group, eyes achieved a 42.4% IOP reduction (from 28.3 ± 12.3 mmHg to 15.3 ± 6.0 mmHg) and a 31.1% reduction (from 22.0 ± 7.2 mmHg to 15.7 ± 4.8 mmHg) in the MP-TLT group. Visual acuity remained primarily unaltered in both groups. Conclusion. MP-TLT was as effective in lowering IOP as CW-TSCPC and achieved comparable success. Additionally, MP-TLT demonstrated consistent and effective outcomes at every time point. The improved safety profile of MP-TLT allows the therapeutic spectrum to be broadened, granting ophthalmologists’ treatment of glaucoma in earlier stages of glaucoma than those typically treated with CW-TSCPC, i.e., early to moderate and to patients with good central-vision.

Spotlight on MicroPulse Laser Trabeculoplasty in Open-Angle Glaucoma: What’s on? A Review of the Literature

Glaucoma is the most common cause of permanent blindness in the world, caused by a progressive optic neuropathy. Patients with glaucoma are often treated with topical medicines therapy in order to reduce intra-ocular pressure (IOP). On the other hand, laser therapies, with the introduction of Argon Laser Trabeculoplasty (ALT) and successively with Selective Laser Trabeculoplasty (SLT), were reported to be effective in IOP control, with low adverse effect rates. In recent years, the micropulse laser, a subthreshold laser technology, was introduced with the goal of reducing side effects while maintaining the effectiveness of the laser treatments. Several studies focused on Micropulse Diode Laser Trabeculoplasty (MDLT) in open-angle glaucoma, to evaluate its effectiveness and possible side effects. Promising results were reported, but irradiation circumstances have not been standardized yet and its role as a substitute for previous laser techniques has yet to be defined. As a result, the goal of this review was to analyze the physical principles at the basis of MDLT and to frame it in the open-angle glaucoma management setting, highlighting the advantages and shortfalls of this technique.

Recent trends in glaucoma surgery: a nationwide database study in Japan, 2011-2019

PURPOSE

To clarify recent trends in glaucoma surgery in Japan, including minimally invasive glaucoma surgery.

STUDY DESIGN

Retrospective cohort study.

METHODS

We used the Diagnostic Procedure Combination database, a nationwide administrative database in Japan. Patients who underwent glaucoma-related procedures were included. We calculated the number of surgeries stratified by procedures and age categories. We also investigated the number of glaucoma-related procedures in combination with cataract surgery.

RESULTS

From fiscal years 2011 to 2019, we identified 134,331 glaucoma-related procedures at 720 hospitals. The total number of glaucoma-related procedures increased by 215% from 6516 in 2011 to 20,569 in 2019. The numbers of filtering surgeries, trabeculotomies, and glaucoma drainage devices with plates [GDD(p +)] procedures significantly increased (P = 0.002, 0.002, and 0.006, respectively), whereas the number of cyclocryotherapy procedures significantly decreased (P = 0.002). The number of iStent procedures increased by 49% from 371 in 2018 to 551 in 2019. The ≥ 65 year age group accounted for > 80% of the iStent procedures. In the 0 to 14 year age group, trabeculotomy accounted for about 70% of the procedures, and the GDD(p +) procedure became the second most common procedure after trabeculotomy because of the decrease in filtering surgeries. Among combination surgeries, trabeculotomy was most frequently performed. The proportion of combination surgery increased, especially in trabeculotomy.

CONCLUSIONS

The total number of glaucoma-related procedures increased throughout the observation period. Before 2017 filtering surgery was the most common procedure, whereas trabeculotomy was most common after 2018. The proportion of trabeculotomies performed in combination with cataract surgery continuously increased.

Angle-closure glaucoma secondary to ciliary body cysts treated with subliminal transscleral cyclophotocoagulation. Report of a case

Angle-closure glaucoma secondary to ciliary body cysts is a rare condition. Different pharmacological and surgical treatment modalities have been described. Among these, subliminal transscleral cyclophotocoagulation is a promising alternative due to fewer ocular complications and the same intraocular pressure reducing efficacy. The case is presented of a 33-year-old woman with a 6-year history of uncontrolled ocular hypertension, and a one-month history of glaucoma, treated with multiple drugs and surgical interventions, with persistent elevated intraocular pressure. She came to the clinic due to eye pain and photophobia of the right eye of 3 days onset prior to her visit. An ultrasound biomicroscopy was performed, finding cysts in the ciliary body. It was then decided to perform subliminal transscleral cyclophotocoagulation, achieving a reduction in intraocular pressure, which was maintained after three months of follow-up.

Blue Sclera as a Complication of Micropulse Transscleral Laser Therapy

We report 3 patients who underwent micropulse laser therapy for glaucoma and subsequently developed a bluish-black discoloration of the sclera in a semicircular pattern corresponding to the probe path. This complication has not yet been reported with the micropulse laser treatment.

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.

Long-term results (>1 year) in 19 dogs treated with MicroPulse transscleral diode cyclophotocoagulation for refractory glaucoma

OBJECTIVE

To report the long-term (>1 year) outcome of MicroPulse transscleral diode cyclophotocoagulation (MP-TSCP) in dogs.

ANIMALS STUDIED

Client owned dogs that underwent MP-TSCP at a veterinary referral center.

PROCEDURE

Retrospective study of 19 dogs treated with MP-TSCP. Dogs were evaluated at a median follow-up time of 30.5 months postoperatively. Reported outcomes were intraocular pressure (IOP), retention or loss of vision, number of medications, and additional procedures performed. Variables associated with time to treatment failure were evaluated.

RESULTS

Data from 19 dogs (24 eyes) was available. Median laser settings employed were 140 s and 2200 mW at 31.3% duty cycle. Long-term postoperative IOP was lower than preoperative IOP values (14 mmHg (IQR = 22 mmHg, range: 4-52 mmHg) versus 30 mmHg (IQR = 31 mmHg, range: 8-62 mmHg), respectively). Laser settings >2000 mW were associated with a significantly longer time to reported failure. MP-TSCP was the sole therapy performed in 16/24 eyes resulting in long-term IOP control in 13/24 eyes and retention of vision in 6 of the 14 sighted eyes. Repeat MP-TSCP was performed in 10/24 eyes. Eight of 24 eyes required additional procedures with long-term IOP control in 4/8 eyes.

CONCLUSIONS

MicroPulse transscleral diode cyclophotocoagulation can be an effective treatment for refractory glaucoma in select cases. Higher laser settings increased time to reported failure, whereas age, glaucoma type, and preoperative IOP did not affect survival. MP-TSCP as sole therapy or coupled with additional glaucoma procedures controlled the IOP in 70% of cases.

Combined Technique for the Application of Micropulse Cyclophotocoagulation in Patients with Uncontrolled Glaucoma: Cyclo Mix

Purpose

To describe the outcomes of a combined technique (Cyclo Mix) in uncontrolled glaucoma cases.

Materials and methods

Retrospective study. The Supra 810 nm subliminal laser (Quantel Medical, Cournon d'Auvergne, France) was used. A combined technique was performed using the subliminal mode (Subcyclo) in one hemifield (power of 2,000 mW, a duty cycle of 35%, and 80–150 seconds), and the continuous wave mode (Thermo Cyclo) on the other hemifield (power of 1,000 mW, exposure time of 2 seconds per spot). The primary endpoint was the probability of surgical failure. Mean intraocular pressure (IOP) change, best-corrected visual acuity (BCVA), number of glaucoma eye drops, and complications at 6 months postoperatively were secondary outcomes.

Results

Twenty-three eyes from 13 patients were included. Mean age was 61.4 ± 16.7 (range: 18–78 years), and 69% were female, with a baseline IOP of 20.3 ± 5.9 (range: 13–38 mm Hg). The cumulative probability of failure was 18 and 22% on days 90 and 180, respectively. Mean IOP reduction was −25.6 ± 20.9% at 6 months. The number of glaucoma eye drops was reduced to 1.2 ± 1 (p = 0.0024) at 6 months. No statistically significant change in the mean BCVA compared with baseline at 6 months was found (p = 0.84), and no severe complications were reported.

Conclusion

Cyclo Mix seems to be a safe therapy that effectively reduces the IOP and glaucoma medications in eyes with uncontrolled open-angle glaucoma for up to 6 months.

How to cite this article

Waldo L-G, Julio H-Q, Jennifer C-V, et al. Combined Technique for the Application of Micropulse Cyclophotocoagulation in Patients with Uncontrolled Glaucoma: Cyclo Mix. J Curr Glaucoma Pract 2020;14(3):93–97.

Micropulse laser trabeculoplasty under maximal tolerable glaucoma eyedrops: treatment effectiveness and impact of surgical expertise

AIM

To evaluate the effectiveness of micropulse laser trabeculoplasty (MLT) for eyes with open angle glaucoma (OAG) under maximal tolerable glaucoma eyedrops and to assess the effect of expertise performing MLT on its clinical effectiveness.

METHODS

Medical records of 42 consecutive eyes of 34 patients diagnosed with OAG who underwent MLT were retrospectively reviewed. The effectiveness was determined using the Kaplan-Meier survival analysis. Failure was defined as an intraocular pressure (IOP) reduction of <20% from baseline, an IOP >21 mm Hg during two consecutive follow-up visits, or surgical intervention for OAG. To determine the impact of MLT surgical expertise on clinical effectiveness, the eyes were divided into two groups according to whether the procedure was conducted by an experienced specialist (defined as a glaucoma specialist who had conducted at least ten MLT procedures) or a less experienced glaucoma specialist. The difference in expertise was determined using a log-rank test.

RESULTS

MLT was conducted by three glaucoma specialists. The overall survival rates were 0.76, 0.48, and 0.44 at 1, 3, and 6mo, respectively. The survival rates for MLT performed by a less experienced glaucoma specialist were 0.62, 0.31, and 0.25 (n=21 eyes) at 1, 3, and 6mo, respectively, whereas the survival rates for MLT performed by an experienced glaucoma specialist were 0.90, 0.64, and 0.64 (n=21 eyes) at 1, 3, and 6mo, respectively. The log-rank test showed a significant difference in the survival curves of the two groups (P=0.0061).

CONCLUSION

The 6-month effectiveness of MLT for controlling IOP is relatively limited in eyes with OAG using maximal tolerable glaucoma eyedrops. However, its effectiveness may be improved if performed by a glaucoma specialist with sufficient MLT experience.

Clinical Outcomes of Micropulse Laser Trabeculoplasty Compared to Selective Laser Trabeculoplasty at One Year in Open-Angle Glaucoma

Background

There is limited long-term data comparing selective laser trabeculoplasty (SLT) to the newer micropulse laser trabeculoplasty (MLT) using a laser emitting at 532 nm. In this study, we determine the effectiveness and safety of MLT compared to SLT.

Design

Retrospective comparative cohort study.

Participants

A total of 85 consecutive eyes received SLT and 43 consecutive eyes received MLT.

Methods

Patients with open-angle glaucoma receiving their first treatment of laser trabeculoplasty were included. Exclusion criteria are prior laser trabeculoplasty, laser cyclophotocoagulation or glaucoma surgery, and follow-up of less than 1 year.

Main Outcome Measures

The primary outcome was success at 1 year, defined as a reduction in intraocular eye pressure (IOP) by ≥20% from baseline or met prespecified target IOP with no additional glaucoma medication or subsequent glaucoma intervention.

Results

Baseline IOP was 18.0 mmHg (95% CI=16.4–19.5) in the MLT group on an average of 1.8 (95% CI=1.4–2.2) glaucoma medications compared to 18.2 mmHg (95% CI=17.2–19.3) for the SLT group on an average of 2.0 (95% CI=1.6–2.3) medications. At 1-hour post-laser, the SLT group had more transient IOP spikes (MLT 5% vs SLT 16%, P=0.10). There was a trend toward increased success in the SLT group compared to MLT at 1 year (relative risk=1.4, 95% CI=0.8–2.5, P=0.30).

Conclusion and Relevance

Eyes had similar success after MLT compared to SLT at 1 year. Laser trabeculoplasty with either method could be offered as treatment with consideration of MLT in those eyes where IOP spikes should be avoided.

[Micropulsed diode laser transscleral cyclophotocoagulation: An effective technique whose role remains to be defined]

Micropulse Transscleral Cyclophotocoagulation (MP-TSCP) is a recently developed cyclodestructive procedure less aggressive than conventional TSCP. In this study, we aimed to evaluate the safety and efficacy of MP-TSCP in a real-life setting.

MATERIAL AND METHODS

We retrospectively included all MP-TSCP cases performed in the Bicêtre Hospital Ophthalmology department between January 2017 and September 2019. Intraocular pressure (IOP) and hypotensive medications were recorded preoperatively, at month 1, 3, 6 and at the conclusion of follow-up, as well as postoperative adverse events. Success was defined as an IOP between 6 and 21mmHg with a decrease of at least one medication or an IOP reduction>20%.

RESULTS

Thirty eyes (28 patients) were included. Preoperative IOP was 27.2±10.6mmHg, with 3.5±0.6 hypotensive medications, the mean deviation on the Humphrey 24-2 visual field was -21.9±6.9dB, and 43% of eyes had a past history of filtering surgery. The mean follow-up was 13.5±8.1 months. Eleven patients (37%) had to be retreated with MP-TSCP during follow-up. At 3 and 6 months and at the conclusion of follow-up, the IOP was 18.3±7.3mmHg (-33%; P<0.0001), 22.5±11.8mmHg, (-17%; P=0.052), 22.7±12.0mmHg (-16,5%; P<0.050), respectively. The success rates were 57%, 50% et 53% at 3 months, 6 months and at the conclusion of follow-up, respectively. Severe adverse events included 3 cases of corneal ulcers and 2 cases of severe but transient ocular hypotony without visual impairment.

CONCLUSION

MP-TSCP is an effective procedure for severe and/or refractory glaucoma, but retreatments are required in more than one-third of cases. Further studies are warranted to define factors predictive of success and indications for retreatment.