AUG 2013

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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August 2013 Diagnostic technologies for February 2011 cataract surgery were similar. However, he views the workflow as much nicer with the Callisto, pointing out that when performing thousands of cataract procedures it's possible to forget to mark quite a few patients. "In those cases it's nice to have a markerless system because it doesn't fail," he said. TrueVision candid Another system available in this preoperative registration sector is the TrueVision system. Preoperatively this uses the unique i-Optics Cassini corneal LED topographer to obtain keratometry, white-to-white and other data along with an eye image for registration, said Mark Packer, MD, clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Ore. With this diagnostic device you're looking at the reflection of lights off the anterior cornea. It uses bright red, yellow and green LEDs. "You have a very bright reflection with a lot of points that overcomes radial symmetry issues with traditional Placido topography," he said. This digital eye image plus the topographic data is routed to the TrueVision 3D system in the operating room for registration with the actual live view using eye features. There a dynamic guidance algorithm incorporates individual surgeon surgically induced astigmatism and cyclotorsion to optimize incision location and toric IOL alignment to the lowest predicted residual astigmatism, Dr. Packer explained. Currently, the topographic portion obtained here involves only the anterior cornea, but Dr. Packer noted that they are working on capturing the posterior cornea as well. He views the system as much more precise than working with a blob of ink, which may be 5 to 10 degrees wide. "This is a thin line that runs right across the image of the eye, so lining the toric lens up is very precise," he said. Dr. Packer uses this registration system in conjunction with the ORA (WaveTec Vision, Aliso Viejo, Calif.), which he said takes into account the posterior cornea. "TrueVision adds a lot for the astigmatism because the one thing that ORA does not allow is registration," Dr. Packer said. Between the two systems Dr. Packer has found that he has an enhancement rate of about 3%, compared with a pretty consistent 8% for sphere and cylinder over the years without these technologies. Going forward, Dr. Packer thinks that it's going to be important to find ways to merge these technologies and see where they fit in with femtosecond cataract surgery. Likewise, Dr. Yoo believes that with the merging of technologies such as intraoperative autorefraction and eye tracking, the ability to perfectly place toric lenses will improve as well. "I think that we'll continue to see this technology evolve in the near future," Dr. Yoo said. EW Editors' note: Dr. Findl has financial interests with Carl Zeiss Meditec. Dr. Osher has financial interests with Alcon, Clarity Medical Systems, BeaverVisitec, and Haag-Streit. Dr. Packer has financial interests with TrueVision 3D Surgical and WaveTec Vision. Dr. Waltz has financial interests with Abbott Medical Optics (Santa Ana, Calif.) and Tracey Technologies. Dr. Yoo has no financial interests related to this article. EW FEATURE Contact information 37 Findl: oliver@findl.at Osher: 800-544-5133, rhosher@cincinnatieye.com Packer: 541 915 0291, mark@markpackerconsulting.com Yoo: 305-326-6322, syoo@med.miami.edu Waltz: 317-845-9488, klwaltz@aol.com

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