Eyeworld

88 | EYEWORLD | DECEMBER 2022 G HOT TOPICS IN OPHTHALMOLOGY UCOMA Contact Grippo: tomasgrippo@yahoo.com Toeteberg-Harms: MarcToeteberg@aol.com by Liz Hillman Editorial Co-Director About the physicians Tomas M. Grippo, MD Founder and Director Grippo Glaucoma and Cataract Center Buenos Aires, Argentina Marc Toeteberg-Harms, MD Associate Professor Medical College of Georgia Augusta University Augusta, Georgia makes this tool a great addition to our surgical armamentarium." In terms of the learning curve, Drs. Grippo and Toeteberg-Harms said it is minimal and that this procedure is generally performed at an ASC. They said that IOP reduction is gen- erally 25–35% if using settings as described in the dosimetry and patient selection guidelines that were published earlier this year (2500 mW, 31.3% duty cycle, and 4 to 5 sweeps at a sweep velocity of 20 seconds each per hemisphere). 1 The physicians think that MicroPulse TLT should be considered once the patient has reached maximum tolerated pharmaceutical therapy and other trabeculoplasty options (ALT/ SLT/MLT) have failed to adequately control the disease. "A conservative approach is to use it after MIGS procedures, trabeculectomy, tube shunts, or non-penetrating procedures have become ineffective to fully control the disease. Another scenario could be a patient with moderate to severe open-angle glaucoma or angle-closure glaucoma without prior incisional or filtering glaucoma surgery on maximum tolerated medi- cations," Drs. Grippo and Toeteberg-Harms said. "Like any glaucoma procedure, it is important to keep in mind that the IOP-lowering effect can diminish over time, or the underlying patho- physiologic disease mechanisms can continue to progress, and the remaining effect may not be enough to control the disease anymore. There- fore, routine checkups need to be performed." As a technique pearl, the physicians said it's important to use a transparent, optically neutral coupling agent, such as lidocaine gel. This offers more effective power transmission. They said to place the footplate of the MicroPulse P3 Device with its "bunny ears" at the limbus or slightly posterior to the limbus if this structure is not well defined. From there, gently compress the conjunctiva for optimal laser transmission. They said to exclude the 3 and 9 o'clock hours. It's also important to understand sweep velocity. "Power, duty cycle, sweep velocity, and the number of sweeps all factor into the suc- cess of the procedure," Drs. Grippo and Toete- berg-Harms said. "In the past, sweep velocity has been the least controlled parameter. Think MicroPulse for the anterior segment surgeon W hile glaucoma specialists are likely familiar with MicroPulse Laser Therapy (Iridex) as a non-incisional, non-pharmaceu- tical glaucoma therapy, Tomas M. Grippo, MD, and Marc Toeteberg-Harms, MD, called it an "ace up your sleeve" and one that can be adopted by any surgeon who treats glaucoma patients. Drs. Grippo and Toeteberg-Harms shared their thoughts with EyeWorld on the technology, which was initially developed in 2015 and has seen a few updates in the years since. First, they described MicroPulse Transscler- al Laser Therapy (MicroPulse TLT) as different from continuous wave transscleral cyclopho- tocoagulation (CW-TSCPC) and endoscopic cyclophotocoagulation (ECP). The company describes it as "tissue sparing," and Drs. Grippo and Toeteberg-Harms said that with MicroPulse TLT the laser does not fire continuously. Rather, it "chops up the energy into smaller micropuls- es," allowing for more thermal control and less tissue damage. In addition, MicroPulse TLT is non-incisional. "While the mechanism of action is not fully understood, it is theorized that MicroPulse TLT enhances the natural aqueous outflow pathways of the eye (conventional and non-conventional) as opposed to restricting aqueous production only," they said. "MicroPulse TLT also focuses the laser energy on a different part of the ciliary body than both CW-TSCPC and ECP. MicroPulse TLT delivers energy to the pars plana portion of the ciliary body or approximately 3 mm back from the surgical limbus." They also said that MicroPulse TLT can be performed in many different types of glaucoma and severity levels. "It is a treatment option in moderate to severe glaucoma, prior to or post-incisional surgery, and in general becomes a surgical option once maximal tolerated pharmacological therapy and trabeculoplasty have failed to con- trol the disease," they said. "Individual patient characteristics, like the status of the angle, conjunctiva, lens, cornea, if the patient is taking or not taking anticoagulation, are less relevant when performing this procedure, and all of this

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