EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78708
44 EW FEATURE February 2011International techniques and technology June 2012 Crosslinking and LASIK: Prophylaxis of the future? by Jena Passut EyeWorld Staff Writer AT A GLANCE • CXL is well established as a way to stiffen the cornea and halt the progression of ectasia and keratoconus • Using CXL as prophylaxis with LASIK gives the added benefits of prevention and regression, accord- ing to one respected surgeon • Surgeons agree more research needs to be undertaken to measure the true benefits of concurrent CXL and LASIK C orneal collagen crosslink- ing (CXL) is well known as an effective way to strengthen and stabilize the cornea in ectatic and keratoconic patients. Minoru Tomita, M.D., execu- tive director, Shinagawa LASIK Cen- ter, Tokyo, believes that using CXL as prophylaxis with LASIK is the ob- vious next use, especially consider- ing that LASIK reportedly weakens the cornea anywhere from 20-40%. Dr. Tomita uses LASIK Xtra (Avedro, Waltham, Mass.), which combines a riboflavin ophthalmic solution (VibeX) with Avedro's KXL UVA irradiation system for CXL dur- ing LASIK. LASIK Xtra has CE mark Eroding continued from page 43 Caldwell believes innovative prod- ucts will continue to be created by smaller companies. "Larger organi- zations have it easier—they're look- ing for innovations they can 'tuck into' current product lines," he said. "There are probably 50-70 compa- nies out there trying to develop truly unique products." "The middle class is growing rapidly in the Third World," Dr. Lindstrom said. With more doctors and more wealth globally, there is a greater need for innovation and technological development, he said. In most advanced countries, people are rapidly aging, and those over 65 years old consume "10 times the eyecare of those under 65," he said. "I'm envious of our colleagues around the world who can come up with innovative concepts and inte- grate them easily into practice," Dr. Osher said. "We can still try, but it's more difficult for U.S. surgeons." That said, Dr. Osher thinks it's the responsibility of every surgeon "to encourage young surgeons to question our methods and tech- niques and to find a better way to help patients. We should always be on the lookout for novel ideas. But we have to remember that an idea is only fertile if there is a way to bring it to market. Ultimately, it's the pa- tient who won't get the benefit of the R&D [research and develop- ment]." When asked about specific areas of innovation, Dr. Osher believes the entire continuum of achieving emmetropia in cataract surgery will be the next big innovation. "The whole concept is thrilling and it's the 'holy grail'—restoring accom- modation and providing pristine uncorrected vision," he said. He's also looking forward to newer drug delivery options in the anterior seg- ment that will eventually negate pa- tient compliance issues. Dr. Lindstrom said the next in- novations will likely be in presby- opia and enhancing refractive outcomes; in glaucoma, the innova- tions will come from less invasive techniques or devices used in sur- gery; in dry eye, "it's all exploding rapidly"; and in the posterior seg- ment, increased efficiency of drug delivery will bring breakthroughs in various retinal disorders. Communication among compa- nies and regulatory agencies world- wide is increasing, becoming more transparent, and that will speed in- novative discoveries around the world, Mr. Peterson predicted. Mr. Caldwell summed it up: "The world is looking for some type of intraocular technology that will give patients the ability to see as well at near/intermediate as they do at distance with the same contrast sensitivity and accommodation that they had in their 20s." EW Editors' note: Drs. Lindstrom and Osher consult for industry. Mr. Caldwell, Dr. Link, and Mr. Peterson have financial interests with their respective companies. Contact information Caldwell: 626-303-7902, bcaldwell@staar.com Lindstrom: 952-567-6051, rllindstrom@mneye.com Link: 949-729-4500, bill@versantventures.com Osher: 513-382-2969, Dr. Tomita uses LASIK Xtra, which combines a riboflavin ophthalmic solution with Avedro's KXL UVA irradiation system for CXL (pictured here) during LASIK Source: Minoru Tomita, M.D. approval but is not commercially available in the U.S. "Patients who choose LASIK Xtra are getting the benefits of prevention of keratoectasia and regression after LASIK," he said. "By performing crosslinking to regain the corneal conditions as closer to the strength at the pre-op stage, there is the potential to prevent iatrogenic ectasia from happening," Dr. Tomita continued. "Published papers have also reported the more corneal tissue ablated by LASIK, the thinner the cornea gets, which results in a higher likelihood of regression (myopic shift) due to the weakened cornea. When the cornea becomes strong after LASIK with crosslinking, it is likely to miti- gate the occurrence and conditions of regression." Dr. Tomita recommends the procedure for patients who are at risk for iatrogenic ectasia, such as high myopes who need a large amount of cornea ablated, patients with atopic dermatitis with less than 480 µm corneal thickness pre-op, or those who are at high risk for devel- oping keratoconus or keratoectasia. Never too thin? Since CXL's primary purpose is to stiffen and stabilize, can it be de- duced that adding the procedure to LASIK means surgeons will be able to operate on thinner corneas—ones they previously wouldn't have con- sidered for the procedure? Despite positive outcomes in ec- tasia and keratoconus patients, Dan Z. Reinstein, M.D., medical director, London Vision Clinic, thinks that might be a bit of a leap. "This implies, but does not prove, that we can do LASIK on thinner corneas if we also simultane- ously crosslink, but it has to be proven," Dr. Reinstein said. "To date, there is no good method of measur- ing the biomechanical stiffening effects of crosslinking; no machine