Eyeworld

EW CORNEA 36 by Liz Hillman EyeWorld Staff Writer From patient selection to tracking progression, postop care, and future directions T he playing field for those interested in getting into corneal collagen crosslink- ing—from experienced surgeons to those still young in their career—is relatively level. The procedure received ap- proval from the U.S. Food and Drug Administration (FDA) a little more than a year ago. "I think the procedure itself is a simple surgical procedure that doesn't require great prior surgical skill and has a very fast learning curve. It's an ideal procedure for a young surgeon to take on," said Michael Raizman, MD, Ophthal- mic Consultants of Boston, who has performed hundreds of crosslinking procedures within the last 5 years. He was an investigator for Avedro's (Waltham, Massachusetts) clinical trial. Michael Greenwood, MD, Vance Thompson Vision, Fargo, North Dakota, said although he didn't learn crosslinking while in residency, it was one of the first procedures he performed on his own after training. "There's not a whole lot to learn from a technical standpoint as a new surgeon, but it's who to do it on and what to watch out for that are part of the learning curve," he said. The FDA approved Avedro's Photrexa Viscous, Photrexa, and KXL System—riboflavin solutions and a UVA light system—in April 2016 for treatment of progressive keratoconus and corneal ectasia post-refractive surgery, following the standard Dresden protocol. Cross- linking, however, has been available in other parts of the world and CE marked for more than a decade. Patient selection "The key, as with many procedures, is understanding who's the right candidate and who is not," Dr. Raizman said. Patients who are candidates for crosslinking in the U.S. under the FDA's approval are those with pro- gressive keratoconus who are at least 14 years old or those who have cor- neal ectasia post-refractive surgery. According to the Dresden protocol, which is the procedural technique approved by the FDA for use with the Avedro system, corneal thickness needs to be at least 400 µm after the epithelium is removed. "In my mind, [a crosslinking candidate] is anyone who has pro- gressive corneal ectasia, whether it's from keratoconus, pellucid margin- al degeneration, or post-refractive surgery ectasia. You want to treat the people who have progression, you want to treat them early because you don't want patients to lose any vision," Dr. Greenwood said. "The hardest part of being a young surgeon is doing a procedure on an eye that corrects to 20/20 for fear of doing harm to that patient, having him or her lose vision. They are the hardest patients to counsel simply for the fact that you're going to be taking their eye that's 20/20 and doing a painful procedure that has a long recovery, and their vision is probably going to fluctuate and get a little bit worse before it gets better. The discussion you have to have with them is that this is something that is preventative and that's going to be beneficial, so they never lose the best corrected vision that they have now." In terms of determining pro- gression, Peter Hersh, MD, founder, Cornea and Laser Eye Institute, Hersh Vision Group, Teaneck, New Jersey, said the best way is to follow the keratoconic patient with serial topography, especially looking at maximum keratography on the Crosslinking: What the young ophthalmologist needs to know I n this month's column, we focus on corneal crosslinking. Crosslinking was approved by the U.S. Food and Drug Ad- ministration in April 2016 for the treatment of progressive keratoconus and corneal ectasia following refractive surgery. The approved device (KXL System, Avedro) was released in fall 2016 amid much excitement and anticipation. Since then, adoption has been gradual, in part due to high out-of- pocket costs for patients because of the lack of insurance coverage. As insurers begin to come on board, we are likely to see wider utilization of this procedure for a broader range of indications. At this time, limited treatment parameters are available to surgeons in the U.S. The Dresden protocol, which involves corneal epithelial debride- ment, application of riboflavin eye drops to the eye for 30 minutes, and subsequent exposure of the eye for 30 minutes to 365 nm UVA light at an irradiance of 3.0 mW/ cm 2 , is currently the only option available in the U.S. Our international colleagues have an array of accelerated and transepithelial treatment protocols to choose from. Our experts share pearls for patient selection and treatment, strategies for counseling patients appropriately, and views on where this technology is headed in the coming years. We asked Michael Raizman, MD, Michael Greenwood, MD, Peter Hersh, MD, A. John Kanellopoulos, MD, and Russel Swan, MD, for their thoughts. Thanks to Charles Weber, MD, and Bryan Lee, MD, the inaugural co-editors of the "YES connect" column. Zachary Zavodni, MD, and I look forward to continuing their work. Naveen Rao, MD, YES connect co-editor Crosslinking procedure performed on a patient Source: Michael Greenwood, MD YES connect June 2017

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