MicroPulse Transscleral Laser Therapy safe and effective treatment for types and severities of glaucoma
MicroPulse Transscleral Laser Therapy (TLT) is a non-incisional laser treatment for glaucoma. The Cyclo G6 Laser and the MicroPulse P3 Delivery Device use an infrared diode laser at a wavelength of 810 nm in which the continuous energy wave is divided into a series of pulses, minimizing tissue temperature elevation and coagulative damage. The laser is “ON” 31.3% of the time (the duty cycle) and “OFF” 68.7% of the time. The MicroPulse technology results in a lower amount of energy being applied over time and, combined with a sweeping technique, delivers a more homogeneous distribution of energy compared to traditional transscleral cyclophotocoagulation (CPC) technique. Lower temperature targets and greater thermal control with MicroPulse TLT contribute to lower the risk of complications compared to continuous wave transscleral cyclophotocoagulation. Furthermore, the recently modified delivery probe has an improved ergonomic design that allows for more stable positioning during the treatment. It also facilitates a more posterior application of laser energy, farther away from the anterior segment structures such as the lens and the iris root
In an effort to refine treatment technique, patient selection, and outcomes of MicroPulse TLT, an international panel of ten glaucoma specialists was formed. The panel published its first paper, “Evidence-based consensus guidelines series for MicroPulse Transscleral Laser Therapy - Dosimetry & Patient Selection”, providing the rationale and recommendations for standard starting dose MicroPulse TLT settings using the revised MicroPulse P3 probe. The publication by Grippo et al summarized the current conceptual understanding of MicroPulse TLT including mechanism of action, indications, cautions in patient selection, and dosimetry. The recommended starting settings for MicroPulse TLT are 2500 mW, 31.3% duty cycle, and 4 sweeps at a sweep velocity of 20 seconds per hemisphere for a total of 160 seconds per eye. This publication also provided guidance on dose escalation of treatment. This same international panel met again to establish consensus on treatment technique, post-procedural management, expected outcomes, and retreatments or enhancements.
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.
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.
Physician experience and literature available during the second consensus Delphi panel have made it possible to reevaluate and revise surgical technique, post-operative care, expected outcomes as well as indications and need for enhancements or retreatments. Technological improvements in laser delivery and a better understanding of all aspects of the MicroPulse TLT treatment have improved the procedure, optimized outcomes, and made it more user-friendly. In turn, this has expanded the indications for MicroPulse TLT compared to traditional transscleral cyclophotocoagulation. Used with proper energy settings, techniques and treatment indications, MicroPulse TLT is a safe and effective treatment for many glaucomas and is a useful addition to the glaucoma treatment armamentarium. Future updates on the evolution of this technique will be provided based on ongoing studies and experience.
Source: Grippo et al; Clinical Ophthalmology 2023:17 71–83
https://doi.org/10.2147/OPTH.S389198
