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57 December 2016 EWAP GLAUCOMA Getting a feel for MicroPulse laser treatment by Rich Daly EyeWorld Contributing Writer Surgeons see a role for the newer technology, but for now its reach appears limited S urgeons have found a growing role for MicroPulse laser cyclophotocoagulation (Iridex, Mountain View, California) among glaucoma patients. But careful targeting is key to use of the emerging treatment. Nathan Radcliffe, MD, clinical professor of ophthalmology, New York University Langone Medical Center, New York, has found MicroPulse laser cyclophotocoagulation provides clinical benefits in several types of patients among the nearly 200 he has treated with it. Patients who immediately benefit have included those with very severe glaucoma, patients with underperforming tube shunts, and patients for whom it is their first surgical intervention because they are not good candidates for standard glaucoma filtration surgery. With experience, Dr. Radcliffe has expanded the therapy to those requiring primary glaucoma surgeries and with moderate glaucoma. Other patients receiving MicroPulse laser cyclophotocoagulation, which he can perform in his office, include elderly patients who have trouble using the operating room, such as those without caregivers to take them home. MicroPulse laser cyclophotocoagulation is used to treat a patient who fits its profile. Source: H. George Tanaka, MD trabeculoplasty (SLT)," Dr. Tanaka said. "This is pretty high when you consider you need to take the patient to the OR, have anesthesia present, and give a retrobulbar block." Dr. Tanaka has used the treatment in patients who are not good candidates for a trabeculectomy, such as younger patients who have already had SLT and are on maximal tolerated medical therapy. He does not want these younger patients to have a bleb—and the risk of associated complications—for the next 30 to 40 years of their lives. The other group of patients Dr. Tanaka treats with MicroPulse laser cyclophotocoagulation are traditional diode laser cyclophotocoagulation candidates—those who have had multiple surgeries, for instance, patients who have a failed trabeculectomy and one or more failed tubes. Additionally, he will use it in neovascular glaucoma patients with poor visual potential and very high IOP. However, he has found MicroPulse may not provide much clinical benefit in neovascular glaucoma patients. Technique Dr. Tanaka uses standard parameters: 2,000 mW, 31.3% duty cycle, and 320 seconds of total treatment, which is given in two 80-second treatments "In my practice I treat a lot of patients who have intraocular tumors, and this is my primary therapy if the patient had a melanoma or other neoplasm," Dr. Radcliffe said. "I treat patients with MicroPulse if they've had a negative experience with traditional glaucoma surgery in the fellow eye," he continued. "You can imagine a variety of scenarios: people who may be on blood thinners or people who are at risk for a fall. They're not great candidates for traditional filtration surgery, but a laser surgery is reasonable." Results differ Dr. Radcliffe has found MicroPulse laser cyclophotocoagulation provided significant pressure reductions in many cases. For instance, some patients have had intraocular pressures reduced from 70 mmHg to 16 mmHg, which allowed them to get off a number of medications, including acetazolamide. Sometimes, the initial treatment did not reduce patient IOPs, but the pressure was reduced after a subsequent treatment on a higher power setting. "If someone had a 2,000 mW treatment and the pressure came down for a week or two but then came back up, I would offer a second treatment with 2,250 mW," Dr. Radcliffe said. Dr. Radcliffe tells patients that the treatment does not work for everyone and that it may need to be repeated. "That is actually part of the plan—we're titrating the proper dose," Dr. Radcliffe said. "I think that many surgeons who do not find the therapy to be effective are not increasing the laser power above 2,000 mW." Conversely, H. George Tanaka, MD, clinical instructor, Department of Ophthalmology, California Pacific Medical Center, San Francisco, California, described MicroPulse laser cyclophotocoagulation as only "modestly" effective in his patients. "My failure rate is about 40%, which is more than selective laser continued on page 59