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EW FEATURE 41 FDA team and physicians who are participating in these new minimally invasive glaucoma sur- gery device trials," Dr. Vold said. "By meeting together, both physicians and the FDA can hopefully better understand how to successfully con- duct these pivotal MIGS trials, and ultimately better serve glaucoma patients across the country." What was discussed Dr. Eydelman's discussion focused on the increase in MIGS devices being developed. She also high- lighted the importance of better descriptions of clinical trial compo- nents to evaluate the safety and effectiveness of MIGS devices. Dr. Kahook discussed efficacy endpoints for MIGS device trials. He clarified when "efficacy" and "safety" can be combined to achieve composite metrics and how efficacy with MIGS devices should not be held to the same standards as more invasive devices that treat glaucoma. "I recommended (and the par- ticipants appeared to agree) that we should also look at what percentage of patients in the MIGS treatment group (with any device) achieved significant IOP lowering (20% lower) compared to the control group inde- pendent of what the final overall mean IOP was for the entire treat- ment cohort," he said, indicating that participants believed it would be significant if 20% to 50% of pa- tients in the MIGS group achieved an additional 20% IOP lowering beyond that achieved from the control group. Dr. Vold's presentation focused on suprachoroidal outflow as a surgical target for the treatment of glaucoma. He discussed how the cur- rent paths for aqueous outflow and suprachoroidal outflow should be a therapeutic target. Suprachoroidal outflow would offer a robust pres- sure gradient, a continuous and absorptive reservoir, and a pharma- cologic precedent, he said. The pres- entation also discussed the way that supraciliary stenting could create a conduit to the suprachoroidal space. Dr. Vold said suprachoroidal outflow could be a promising MIGS target because preliminary safety results seem to be similar to other MIGS devices; the anatomical approach could help create a more elegant procedure; and it has potential for the best IOP-lowering efficacy. Important issues One of the important issues with MIGS devices is to clarify what the "significance" bar is for IOP lower- ing using these devices that are safer than traditional devices but might have lower efficacy compared to more invasive approaches, Dr. Kahook said. "An important concept is that it might be very significant if only a small percent of the MIGS group achieves IOP lowering beyond that achieved by the control because the downside is insignificant." One of the topics that came up at the meeting was the specifics of the MIGS device studies and the definitions pertaining to glaucoma. "We should have some repro- ducibility among the studies," Dr. Vold said, citing the first Glaukos trial for the iStent, which was a 1-year trial with no washouts, and explaining that there is not necessar- ily uniformity in studies for MIGS devices. Dr. Eydelman said the design of the trial is important for future ap- proval of these devices. "One must clearly determine the subjects that should be enrolled and what end- points would demonstrate device safety and effectiveness," she said. "There was quite a debate about how advanced the glaucoma should be to be a part of these trials," Dr. Vold said. "The one thing that was very clear to me is that the people who had the most experience in the clinical trials had a different perspective than those who were less experienced." These studies can be difficult to enroll, Dr. Vold said, and this is an aspect that needs to be addressed. He added that enrolling patients earlier in the spectrum of glaucoma- tous disease could potentially be advantageous for patients. Dr. Eydelman said that the CDRH is planning to develop guid- ance that will detail what patients should be enrolled in these trials. Approval for other MIGS devices Dr. Kahook said that over the next 6 months to 3 years there will likely be other MIGS devices approved for use in the U.S. "There are MIGS devices that are closer to being marketed in the U.S. that do not require the PMA route for approval," he said. Dr. Kahook said that he believes the next devices going through the PMA route will likely make it to market in the next 3 years. EW Editors' note: Dr. Vold has financial interests with AqueSys, Glaukos, Ivantis, Transcend Medical, and NeoMedix. Dr. Kahook has financial interests with Aerie Pharmaceuticals (Bedminster, N.J.), Alcon (Fort Worth, Texas), ClarVista Medical (Aliso Viejo, Calif.), Allergan (Irvine, Calif.), Glaukos, Oasis Medical (Glendora, Calif.), New World Medical (Rancho Cucamonga, Calif.), Mile High Ophthalmics, OcuTherix (Stillwater, Minn.), ShapeTech (Colorado Spring, Colo.), and Shape Ophthalmics (Denver, Colo.). Contact information Eydelman: malvina.eydelman@fda.hhs.gov Kahook: malik.kahook@ucdenver.edu Vold: svold@cox.net May 2014 Poll size: 235 EyeWorld Monthly Pulse EyeWorld Monthly Pulse is a reader survey on trends and patterns for the practicing ophthalmologist. Each month we send an online survey covering different topics so our readers can see how they compare to our survey. If you would like to join the hundreds of physicians who take a minute a month to share their views, please send us an email and we will add your name. Email carly@eyeworld.org and put EW Pulse in the subject line—that's all it takes. Copyright EyeWorld 2014

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