Eyeworld

85 EW FEATURE March 2016 • Intracorneal inlays Like other presbyopia-correct- ing options, inlays have their own unique set of advantages and some disadvantages, and there are pros and cons among the different types of inlays, making patient selection a key factor for success. Ultimately though, William Wiley, MD, med- ical director, Cleveland Eye Clinic, said he thinks ophthalmologists will benefit from them as another tool to give patients more choices to reach their desired refractive outcomes. "What's nice is [inlays are] a dynamic solution for a dynamic problem," Dr. Wiley said, explaining that they age well as patient vision changes over time. What are the options? The KAMRA, which some practices are just starting to offer, uses the same optical principle as that used in a disposable camera, said Richard Lindstrom, MD, adjunct professor emeritus, Department of Ophthal- mology, University of Minnesota. Using small diameter aperture optics, the KAMRA is placed in a patient's non-dominant eye within a small pocket created in the cornea with a femtosecond laser. Surgeons ensure proper cen- tration—the most "critical" factor for successful patient outcomes, Dr. Lindstrom said—using the AcuTarget HD, which was developed by AcuFocus to work with the KAMRA to help identify the center of the visual axis for inlay positioning. The Raindrop, which is com- mercially available in the European Union and had the FDA accept its premarket approval submission in November 2015, is placed under a LASIK-like flap and works much like a multifocal IOL by creating a mul- tifocal cornea. The inlay is thinner at its edges and reaches up to 32 microns at its center to achieve this effect. Dr. Wiley thinks the Raindrop could work best in patients who have a minimal amount of hypero- pia. The Flexivue is in a phase 3 clin- ical trial in the U.S. and has received the CE mark in Europe. This inlay is placed in a pocket created with a femtosecond laser in the cornea. It has a refractive power built in that is carefully selected by the surgeon based on the patient's needs. Dr. Lindstrom said a potential challenge with the Flexivue and the Raindrop is that a stronger power might be needed as the patient continues to age over time, while the KAMRA is more "one-stop shop- ping," he said. The Flexivue could be benefi- cial to younger patients, Dr. Wiley said, because they could require a lesser power that would then make adjusting to the device easier. Such a patient might require multiple surgeries over time to increase the power with new inlays as needed. A patient who might benefit from the Flexivue is someone who has done well with monovision contact lenses, Dr. Wiley said. All of these inlays are designed to allow nutrients to pass freely through them. On a macro-scale, Dr. Hovanesian said success of the inlays is "remarkably similar," based on the data. "There are dif- ferences [among the inlays] that are important, but from a standpoint of patient results, they're all fairly similar," he said. A 3-year follow-up study pub- lished in January 2012 in the Journal of Cataract & Refractive Surgery about patients who had received the KAMRA supported the longer-term safety and continued efficacy of the inlay. 1 Of the 32 patients surveyed, 84.5% said they would have the procedure again. As for the learning curve, Dr. Hovanesian said it's relatively short because "most surgeons performing these inlays are already performing LASIK, using femtosecond lasers, and dealing with corneal flaps." "What makes these procedures different is that there is a very delicate implant to be handled with implant instruments and a corneal pocket, which is a somewhat dif- ferent operating environment," he said. "For most surgeons, these hur- dles are fairly easily to overcome. " "With inlays it's the postop care that's a greater challenge than the technique itself," he added. Dr. Wiley said that proper pa- tient selection is something surgeons will need to learn as well. Who's the best candidate? The ideal candidates for inlays, Dr. Hovanesian said, are patients who are generally younger presbyopes, have healthy eyes, and have always had good distance vision without glasses. "These fit patients who are healthy but are 55 years old and are fed up with reading glasses," he said. "In the past, the only choice for these folks was to give them mono- vision, but in an ideal world, you wouldn't compromise their distance vision." Patients who have already de- veloped presbyopia and are myopic would likely get LASIK to correct their distance vision first and then have an inlay placed for their near A laser technician who has worked closely with Dr. Wiley, operating excimer lasers for nearly 20 years, recently had the KAMRA inlay placed in his right eye. Source: William Wiley, MD continued on page 86

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