EyeWorld Asia-Pacific June 2016 Issue

June 2016 EWAP CORNEA 49 by Maxine Lipner EyeWorld Senior Contributing Writer Presbyopia inlays at the outset: Getting the near view Red re ex of a KAMRA inlay in situ Source Perry Binder, MD A look back at corneal inlay development and a look ahead to where they may best fit in the realm of presbyopia treatment W ith the ubiquitous problem of presbyopia always looming, approaches to correct this have a ready market. Recently, several corneal inlays, the KAMRA (AcuFocus, Irvine, Calif.), the Raindrop Near Vision Inlay (ReVision Optics, Lake Forest, Calif.), the Flexivue Microlens (Presbia, Dublin), and the ICOLENS (Neoptics, Hunenberg, Switzerland), have emerged ready to help this ever-growing population. For many years the treatment standard for presbyopia in the U.S. was monovision, whether this was done with corneal laser surgery or implants, according to Daniel Durrie, MD , professor of ophthalmology, University of Kansas Medical Center, and president, Durrie Vision, Overland Park, Kan. “Monovision works—many surgeons endorse it,” Dr. Durrie said. “But when you focus one eye up close and the other far away, there is some compromise in stereopsis—some decrease in distance vison in the monovision eye.” Also, there is some neuroadaptation that can take months for some patients. While other solutions have been tried, nothing else has caught on. As a result, monovision has been the chief go-to procedure here, he noted. Inlays at the start Corneal inlays have made strides in the presbyopic population. Development of the KAMRA inlay started 13 years ago. “It went through several iterations of design and then started FDA clinical trials 9 years ago, and it has been available internationally since 2011,” Dr. Durrie said. This was FDA approved in April The Flexivue Microlens Source: Gustavo Tamayo, MD 2015. With two other inlays, the Raindrop and the Presbia, now in clinical trials in the U.S., interest is mounting. “We’re starting to have a lot of interest from ophthalmic surgeons on where this is going to fit within our treatment suggestions for patients with presbyopia,” Dr. Durrie said. While all the inlays are geared to change the point of focus of the near objects, they actually do this in one of three different ways, said Gustavo Tamayo, MD , director, Bogota Laser Center, Bogota, Colombia. “The KAMRA works with the pinhole effect. The Flexivue Microlens works with a refractive addition to the cornea,” Dr. Tamayo said, adding that it is akin to a near add in bifocals. As for the Raindrop Near Vision Inlay, it works by increasing the bulk of the cornea, thereby increasing its refractive index. Perry Binder, MD , clinical professor, Gavin Herbert Eye Institute, University of California, Irvine, Calif., pointed out that of these inlay approaches, only the one that increases the depth of focus, the KAMRA inlay, is age-insensitive. The others, the Raindrop, the Flexivue, and the ICOLENS, work primarily by correcting a fixed focal length, he noted. “To get a change in correction with these inlays as patients get older, you’ve got to change the inlay or go to spectacles, contact lenses, or PRK,” Dr. Binder said. “Depth of focus stays forever—that does not change irrespective of age.” “I think current inlay models are all viable, and they probably will be used for different patients,” Dr. Durrie said. “The KAMRA inlay has been the most flexible because of the depth-of- focus principle and because it was the first to get approval and has the highest volume.” FDA clinical investigators found that the KAMRA inlay did improve near vision, with very little compromise to distance, Dr. continued on page 50