Eyeworld

101 EW FEATURE March 2017 • Advances in corneal inlays benitsch said. "First, we are not yet sure of how the cornea will remodel with placement of the Raindrop inlay within a pocket," he said. "As the inlay functions through creation of a hyper-prolate cornea, there is some concern that this effect may be diminished with pocket placement." He added that excimer laser is often used off label in conjunction with corneal inlays to provide a superior visual outcome in patients who would be less than ideal can- didates due to preoperative refrac- tion. "For the KAMRA, it is likely best to place the inlay in a deeper pocket and create an anterior flap under which the ablation is per- formed." However, he said there are some surgeons who advocate commercially available femtosecond lasers would be amenable for this. "The femtosecond laser has absolutely revolutionized corneal refractive surgery, and corneal inlays are no exception," Dr. Rebenitsch said. The two inlays available in the U.S. currently, the KAMRA and Rain- drop (ReVision Optics, Lake Forest, California), both have improved results with femtosecond lasers, he added. "In fact, use of a femtosec- ond laser is indicated when placing them." Inlays can provide a superior outcome to what monovision can provide. "However, their placement requires a consistent and accurate bed for best results," he said. "In the IDE study for the KAMRA inlay, it was found that extremely tight spot/ line separations resulted in superior visual outcomes." Dr. Rebenitsch said that type of precision cannot be achieved with manual techniques. Depth is also important because there is a higher density of kerato- cytes in the anterior stroma, and an inlay that is placed too shallow in the cornea has a much higher risk of haze. "Again, this precision cannot be achieved with manual tech- niques," Dr. Rebenitsch said. Pocket vs. flap Pockets have many benefits over flaps, Dr. Rebenitsch said. "They affect the stability of the cornea less and can therefore be safely placed at greater depths," he said. "There is less risk of inlay decentration after placement." He added that the pa- tient experience postoperatively can be improved as the incision length is reduced, resulting in fewer corneal nerves being transected and less postoperative dry eye. "For the above reasons, pockets are the preferred, as well as indicated method, for placement of the KAM- RA inlay," Dr. Rebenitsch said. "The Raindrop inlay is currently indicated to be placed under a corneal flap at 30% thickness." However, he said, pocket studies are underway, and many surgeons are placing these in- lays in pockets currently. "I do think this will be the preferred method for the Raindrop inlay in the future," he said. There are some theoretical reasons that placing an inlay under a flap may be preferable, Dr. Re- 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. Poll size: 103 continued on page 102 pay for it once, you get it inserted once, and one day when you have cataracts you get a reinvigoration of your benefit, which is a nice treat," Dr. Waltz said. Dr. Waltz said he has performed several cataract surgeries with an inlay in position. "You have to get over your con- cern that you cannot see the entire field," Dr. Waltz said. "It turns out that you are stroking with your pha- co handpiece through these blacked out zones, but it doesn't harm anything, it doesn't slow down your surgery, and it's very doable." Visualizations with an inlay can come from rotating the globe to look at different parts around the inlay, Dr. Waltz said. An important note is that femtosecond cataract surgery should not be performed through an inlay, the surgeons said. The black KAMRA inlay is highly absorbent of infrared energy, heats up, and harms the cornea with the heat. Similarly, a Raindrop will distort the layer of the cornea the laser will cut. "For those two reasons you cannot use femtosecond lasers with either of the current corneal inlays in place," Dr. Waltz said. Another important note is that although corneal surgery can make cataract surgery calculations more difficult and the outcome less pre- dictable, inlays do not complicate calculations, Dr. Waltz said. Dr. Waltz said calculations with the KAMRA inlay should use the center point on the topographer— not manual keratometry or simulat- ing tables—to account for changes in the keratometry. EW Editors' note: Dr. Wiley has financial interests with AcuFocus, ReVision Optics, and Abbott Medical Optics. Dr. Pepose has financial interests with Acu- Focus. Dr. Waltz has financial interests with AcuFocus and Abbott Medical Optics. Contact information Wiley: drwiley@clevelandeyeclinic.com Waltz: kwaltz56@gmail.com Pepose: jpepose@peposevision.com Roles continued from page 99

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