EyeWorld India March 2014 Issue

39 EWAP rEfrActivE March 2014 Raindrop corneal inlay shows promise for all degrees of vision correction by Ellen Stodola EyeWorld Staff Writer continued on page 41 Early results for the inlay indicate potential for the future T he Raindrop (ReVision Optics, Lake Forest, Calif., U.S.) is just one of several corneal inlays in development for the treatment of presbyopia. Roger Steinert, MD, chair, Department of Ophthalmology, University of California, Irvine, Calif., U.S., and director, Gavin Herbert Eye Institute, Irvine, Calif., U.S., spoke at the 2013 American Academy of Ophthalmology meeting about the advancements and results of the Raindrop so far. He followed up with input on what’s to come from the inlay. George Waring IV, MD, assistant professor of ophthalmology, and director of refractive surgery, MUSC Storm Eye Institute, and medical director, Magill Vision Center, Charleston, SC, U.S., commented on the Raindrop and other presbyopia inlays. “We all know that the current options for presbyopia correction are less than fully satisfactory,” Dr. Steinert said at the meeting. There are options like monovision and multifocality, but there is a struggle to find an alternate technology that can give near and intermediate vision with little to no compromise to distance vision. What is the raindrop? Dr. Steinert explained in his presentation that the Raindrop is a physiological and transparent corneal inlay. It is a hydrogel and is biocompatible, with a water content and refractive index that is the same as the cornea so that The Raindrop Near Vision Inlay is a 2-mm hydrogel corneal inlay. Source: ReVision Optics nutrients can flow through it. He added that it is only 2 mm in diameter and approximately 30 µm thick, which varies depending on the power. The inlay is easily inserted under a flap and can be removed if the results are not satisfactory. “It reshapes Bowman’s layer and the anterior cornea,” Dr. Steinert said. “This gives a gradient of power with smooth transitions for near, intermediate, and distance.” “The easiest way to think about the different presbyopic inlays is by mechanism of action because they’ve changed names and design so many times through the years,” Dr. Waring said. “The Raindrop is unique in that it’s a permeable hydrogel lenticule that allows for nutrient flow and fluid flow. This is a space occupying lenticule that is the only one of its kind on the market.” He explained that the Raindrop has the same refractive index as the cornea, meaning that it has no refractive power but creates a hyperprolate shape of the cornea to help increase the depth of focus and provide a broader range of vision. Dr. Waring said that this is different from the other inlays, like the KAMRA (AcuFocus, Irvine, Calif., U.S.), which uses a small aperture, or others that have refractive power. How to insert the inlay In order to insert the Raindrop inlay, Dr. Steinert said to start by making a flap at one-third of the depth of the corneal thickness, which typically is about 150 µm, that initially reshapes the front in a parallel manner. “The key that makes this work so well optically is remodeling of the cornea that goes on anteriorly with epithelial hyperplasia and remodeling to give this prolate shape and hence the term profocal,” he said. What preop refractive error or range of errors is ideal? At the 2013 AAO meeting, Dr. Steinert spoke about recent result of studies that were undertaken to determine what preoperative refractive error or range of errors is ideal for implanting the Raindrop. Looking at specific results of 188 subjects who were implanted