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

Settings and effectiveness of the revised probe compared to the original probe for micropulse transscleral cyclophotocoagulation

PURPOSE

The goal of this study was to compare the settings and effectiveness of the original P3 and revised P3 probes for micropulse transscleral cyclophotocoagulation.

METHODS

This retrospective cross sectional study includes a total of 56 patients with glaucoma who received micropulse transscleral cyclophotocoagulation. 32 patients received treatment with the original P3 probe and 24 received treatment with the revised P3 probe. Success was defined as a 20% reduction in intraocular pressure. Laser settings, pre-op and post-op intraocular pressures, and pre-op and post-op medications were assessed.

RESULTS

A 20% IOP reduction was achieved in 50% of patients in the original probe vs. 58.3% in the revised probe at one month (P = 0.536) and 71.9% vs. 50% at three months (P = 0.094), respectively. The revised P3 probe used higher values of power (2500 mW vs. 2023 mW, P < 0.0001), total duration (217 s vs. 179 s, P < 0.0001), and energy (170 J vs. 113 J, P < 0.001). There was a significant decrease in IOP lowering meds with the original probe at one month (-0.9 +/- 1.5 vs. -0.0 +/- 0.7, P = 0.010), but this was not seen at three months.

CONCLUSIONS

There is no significant difference in IOP lowering effect between probes despite the revised probe using higher total energy. The original probe may be associated with fewer medications at 1 month, but not at 3 months. Further studies with longer follow up are needed to optimize the treatment parameters in order to maximize effectiveness while limiting side effects.

A Systematic Review of Cyclophotocoagulation Techniques: Continuous Wave Versus Micropulse for Glaucoma Treatment

Objectives

Micro-pulse cyclophotocoagulation (MP-CPC) represents the latest iteration of minimally invasive laser procedures aimed at reducing intraocular pressure (IOP) through the disruption of pigmented ciliary body epithelium. This systematic review aims to assess the efficacy and safety profile of the MP-CPC procedure in comparison to CW-CPC for the treatment of glaucoma.

Methods

We initiated a search on PubMed, ScienceDirect, and the Cochrane Library databases for studies that compared micro-pulse and traditional CW-CPC in terms of their efficacy and safety profiles. We employed medical subject headings terms and keywords such as "cyclophotocoagulation," "cyclodestructive," "photocoagulation," "CPC," "micropulse," "micro-pulse," and "glaucoma" within the timeframe from 2015 to 2023. We assessed the success rate, IOP reduction, antiglaucoma medications, and complications of MP-CPC and CW-CPC.

Results

We included six articles in this study, comprising two randomized controlled trials, three retrospective, and one prospective cohort, published between 2015 and 2023. Five out of six reported a significant reduction in IOP for both procedures with comparable success rates observed in MP-CPC compared to CW-CPC. One article reported an increase in IOP in MP-CPC. Both groups reported a decrease in the number of antiglaucoma medications, while one study reported an increase in medications in both MP-CPC and CW-CPC groups. Complication rates were lower in the MP-CPC group with two articles reporting a significant decrease compared to the CW-CPC group.

Conclusion

MP-CPC has shown promising results in the treatment of glaucoma in the adult population. With comparable results in IOP reduction and fewer instances of serious ocular complications, MP-CPC may open new possibilities for the use of cyclophotocoagulation procedures in the earlier stages of glaucoma. However, its efficacy in the pediatric population and for neovascular glaucoma remains less defined, thus warranting further studies to establish optimal laser parameters for different types of glaucoma and specific populations of glaucoma patients.

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.

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.