EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/137624
44 EW REFRACTIVE SURGERY June 2013 Device focus Corneal inlays have the potential to Ôtreat millionsÕ by Michelle Dalton EyeWorld Contributing Writer All that's needed is U.S. regulatory approval, most surgeons say The devices also have the potential to extend the LASIK market for people who are in their late 40s or early 50s, he said. In the Netherlands, Dr. Verdoorn creates a 150-micron, 8 mm flap with a 150 kHz femtosecond laser, and suggests surgeons ensure the flap is well centered before proceeding, especially in hyperopes. "These need to be in the best position possible to get the best possible vision," Dr. Whitman said. "If the inlay is not positioned properly, it might affect distance vision." He has yet to have that happen in any of his patients, but did note the possibility. C orneal inlays are designed to treat presbyopia by being inserted in the nondominant eye and correcting for near vision; distance vision remains (mostly) unaffected. Three devices are currently under investigation in the U.S., with the AcuFocus (Irvine, Calif.) KAMRA inlay already filed for regulatory approval. The remaining two devices—the ReVision Optics (Laguna Hills, Calif.) Raindrop and the Presbia Flexivue Microlens (Presbia, Amsterdam)—are in trials. "It probably doesn't matter which inlay is first to market," said John A. Hovanesian, MD, faculty member, Jules Stein Eye Institute, Los Angeles. "When we talk to patients who are presbyopic, many who have heard of monovision are just not interested. They love the idea that they can get an implant that gives them near vision without the compromises of distance vision." The inlay market overall "is very promising," said George O. Waring IV, MD, assistant professor of ophthalmology, director of refractive surgery, Storm Eye Institute, and medical director, Magill Vision Center, Medical University of South Carolina, Charleston. "In a global depressed economy, outside the U.S. it's the inlays that have increased volume for practices." Further, since "100% of people get presbyopia, there is a huge market opportunity as patients are not aging gracefully anymore," Dr. Waring said. "Some of my most motivated patients are new presbyopes who never had to wear glasses before." Inlays "will be a game changer for those who get involved with it and are not afraid to make a flap or a pocket (or probably both)," said Jeffrey Whitman, MD, president and chief surgeon, Key-Whitman Eye Center, Dallas. "We're going to have a whole new range of products for the presbyope; if the patient really dislikes the inlay, we can remove it and the patient returns to preop vision." The "ideal" inlay candidate is someone in the 50- to 60-year-old range, said Cees Verdoorn, MD, medical director, Lasik Centrum Artist's rendering of the Raindrop inlay Source: ReVision Optics Oogkliniek, Boxtel, the Netherlands. He explains to patients that the inlay is a "spacer" that's placed into the cornea to make it steeper in the center. "This has to be a very precise placement, or the patient may end up with blurred vision," he said. Dr. Hovanesian said both the Raindrop and the KAMRA seem to improve distance vision to about 20/25, with near vision close to J1 or J2. Drawbacks to the technology include the potential for decentration and the possibility that the patient may have a foreign body sensation, Dr. Whitman said. Prior LASIK patients People who had previously undergone LASIK are as viable candidates as those who have never had surgery, Dr. Hovanesian said. "Just go beneath the flap that already exists to place the inlay," he said. "For the KAMRA, the technique involves making a pocket, and the other inlays will probably follow suit. Assuming the cornea is thick enough to have some space, the small pocket is unlikely to cause significant damage to the first flap, particularly if it's been years since the first flap was made." Learning curves These devices have short learning curves, Dr. Waring said. "Any corneal refractive surgeon can pick it up very quickly," he said. "Using an advanced femtosecond laser is important for the pocket or flap. Centration is important, too—inlays are forgiving enough that patients will do well as long as the inlays are generally placed correctly. And, of course, patient selection is critical. We recommend healthy eyes—you really want to optimize the ocular surface." The KAMRA can be "easier to see during the day if the light hits it right," Dr. Whitman said. "Other Wavefront Optimized RefraXion We all know that 'time is money', but do you know how to 'buy more time'? OPD-Scan III wavefront system measures >20 diagnostics – and how cleanly light passes through the optical path. In less than 1 minute, Wavefront Optimized refraction can discern which patients will/will not require a full refraction to achieve 20/20.