The effect of various media and probe angles on the power output of the Cyclo G6 Glaucoma Laser System

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.

Evaluation of laser power stability of repeatedly used SubCyclo probe in micropulse transscleral cyclophotocoagulation for glaucoma: A step towards sustainable ophthalmic surgery

PURPOSE

To evaluate the laser power stability of the SubCyclo probe for micropulse transscleral cyclophotocoagulation after repeated use.

MATERIALS AND METHODS

This experimental study involved 6 new probes. Each probe was connected to the SubCyclo mode (2,000 mW power, 31.3% duty cycle, and 100 seconds duration) of the Vitra 810 laser delivery system (Quantel Medical, France). Laser power measurements were taken using a calibrated laser power meter (Nova, Ophir Optronics Solutions, Israel) every 10 seconds from 10 to 90 seconds during each of the 40 cycles. Intra-rater reliability was assessed using intraclass correlation (ICC). A linear mixed model for repeated measures and pairwise comparisons with Bonferroni adjustment were used for the analysis.

RESULTS

The mean (SD) power outputs of all probes for the first cycle and all cycles were 421.9 (19.7) mW and 436.7 (16.1) mW, respectively. During the first cycle, the mean (SD) laser power gradually decreased from 444.3 (13.4) mW at 10 seconds to 407.3 (17.0) mW at 90 seconds (Fig 3). For all cycles, the power was 446.0 (13.6) mW at 10 seconds and gradually declined to 426.8 (21.0) mW at 90 seconds. Pairwise comparisons revealed significant differences in mean laser power outputs after 16 cycles of repeated use compared to the first cycle. The ICC estimate (95% CI) for intra-rater reliability was 0.96 (0.89, 0.99).

CONCLUSIONS

The SubCyclo probe maintains stable laser power outputs throughout repeated use for up to 16 cycles, with a significant increase observed after 16 cycles.

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.

Evidence-Based Consensus Guidelines Series for MicroPulse Transscleral Laser Therapy - Surgical Technique, Post-Operative Care, Expected Outcomes and Retreatment/Enhancements

Purpose

To provide expert consensus and evidence-based current guidelines on treatment technique, postoperative care, expected outcomes and retreatment for MicroPulse Transscleral Laser Treatment (TLT).

Methods

A comprehensive search of PubMed led to the identification and analysis of 61 studies on MicroPulse TLT. To provide guidance in areas where there was not enough available literature, a three-round Delphi method was conducted involving 10 international experts in MicroPulse TLT.

Results

The response rate was 70% in the first round, 70% in the second round, and 80% in the third round of the Delphi method. Once all responses were aggregated, a live meeting was held with 90% attendance, and consensus was achieved on each of the findings detailed in this manuscript.

Conclusion

Used within appropriate treatment parameters, with proper technique and patient selection, MicroPulse TLT is a safe and effective treatment for many types and severities of glaucoma. MicroPulse TLT represents a useful addition to the glaucoma armamentarium.