EyeWorld Asia-Pacific March 2011 Issue

AT A GLANCE • Four femtosecond systems are breaking new ground in cataract removal • The LenSx system, with integrated OCT, has already cleared most FDA hurdles with 510K clearance for four cataract surgical indications—anterior capsulotomy, phacofragmentation, and the creation of single- and multi-plane incision • Optimedica’s Catalys Precision Laser System relies on a liquid optics interface and an on-board internal OCT guidance system to help to precisely and accurately remove cataracts • The LensAR system boasts unique 3D, confocal, structured illumination software, which delivers high-resolution images from the top of the cornea to the posterior capsule. • A distinguishing feature of the Technolas workstation 520F is its in-line OCT device which allows live OCT imaging for guiding the beam, planning the surgery and also tracking various stages of the cataract removal procedure March 2011 12 EW FEATURE By the time phacoemulsification is started a good portion of the work has been completed. “You sit down and the incision has been made, the capsulotomy has been made, and the nucleus is cracked,” Dr. Slade said. “So, then you just have to remove the nucleus, remove the cortex and implant the IOL.” One of the benefits of the femtosecond technology in terms of results is its consistency. “The capsulorhexis has helped with effective lens positioning,” Mr. Raetzman said. “All of this precision is terrific for a lot of reasons, but in particular it allows the surgeon to better predict where the lens is going to sit in the eye.” This ultimately enables surgeons to consistently achieve their target refractive outcomes. Dr. Slade is very excited about the new femtosecond approach. “I think that it’s a tipping point for ophthalmology,” he said. “If you plucked me out of 1985 and dropped me into my current clinic I would be at a loss with everything except for phaco cataract surgery—that really hasn’t changed fundamentally in 25 years.” Soon, however, he thinks that it will be a different story. “I think that this technology will change cataract surgery at its core,” he said. “It’s not going to get rid of phaco but it will make a whole new type of phaco.” Mr. Raetzman likewise sees complimentary roles for the new femtosecond technology and traditional phacoemulsification. He likens the femtosecond laser to a highly advanced knife. “It’s going to replace those things that were done with blades and sharp pieces of metal,” he said. Because of these complimentary roles he feels that the LenSx technology is in a unique position. “I think that that is a really important difference between Optimedica and LensAR who are looking at this from a laser perspective and Alcon which really is trying to look at the procedure as a whole from the time that we first drape the patient to the time at his or her postoperative visit.” Mr. Raetzman expects the first few units to be available at the end of 2010 and to broaden the commercialization of this in the second half of next year. The Optimedica approach The Optimedica Catalys Precision Laser System likewise is designed to perform capsulotomy, segmentation, fragmentation of the lens and relaxing incisions, according to Mark J. Forchette, president and CEO, Optimedica. There are, however, some things that he sees as setting the system apart. “For us and for what we focused on some of the really distinguishing elements are things like the patient interface,” he said. In this case a liquid optics interface is used. “It is a very unique approach that we arrived at after a lot of development work and iteration,” Mr. Forchette said. “We settled on the liquid optic approach really to ensure that we had minimal IOP increase for the patient so that it’s comfortable for them.” He finds that this addresses any corneal aberrations and that it also has been very effective at eliminating corneal folds Mr. Forchette sees the on-board OCT, a system dubbed integral guidance, as another key element. “Every patient has been treated with an image-guided, OCT- guided treatment—we were really early with that piece of forward thinking,” he said. “Although it’s technically sophisticated it’s really easy to use with great graphics that lets physicians establish safety zones, exclusion zones and to deliver a treatment that is very effective.” With the Catalys precision laser system the procedure starts with the capsulorhexis. “We do that part of the procedure first,” Mr. Forchette said. “One of the great benefits of the precise OCT that we have is that we’re able to really minimize the cutting area that we have to deliver.” As a result, he finds that the procedure is more efficient without a spray of bubbles, enabling practitioners to do capsulotomy first and then to move on to segmentation and softening as well. Mr. Forchette has found results with the technology to be extremely promising. “In our clinical trials we treated at an average depth in the nucleus of 4.3 mm from the anterior capsule,” he said. “That helped us to be really effective in lochs grade 4+ nucleus procedures such that we reduced ultrasound use by 40%.” When compared to traditional phacoemulsification, Mr. Forchette sees the overarching element favoring femto-emulsification as centering on precision. “In our clinical evaluation we did a head- to-head comparison of the Catalys system with a manual approach for capsulotomy and with the manual group of patients in our trials the physicians’ deviation from the intended diameter or target was on average 339 microns,” Mr. Forchette said. “In the Catalys group the deviation from the intended target was [just] 27 microns so that was an order of magnitude there.” Also, when investigators looked at the circularity as an element here, where 1.0 was considered a perfectly circular result, they found that once again Catalys system was more precise. “In the manual group the mean was .765 and in the laser group .942,” Mr. Forchette said. “So, everywhere that we compare the precision of the laser is extraordinary.” He envisions phacoemulsification as continuing to play a role but in concert with the new technology. “I think that phaco has been an incredible technology and has been extremely effective and will continue to be utilized,” he said. “If you look at really dense nucleus we segment it into really small easily aspiratable pieces, yet physicians I think will still utilize phaco and ultrasound technology for elements of the procedure.” Nevertheless, he envisions that the procedure will evolve considerably. “I think that you’re going to see a whole new world of nuclear disassembly techniques that emerge based on having pre-segmented the nucleus with this,” Mr. Forchette said. LensAR design The LensAR system is a single platform that currently treats cataracts and has the potential for treating presbyopia as well, according to William J. Fishkind, MD, clinical professor of ophthalmology, University of Utah, Salt Lake City, Utah, USA, and clinical instructor of ophthalmology, University of Arizona, Tucson, Ariz., USA. He believes that one of the things that distinguish the system from several of the others is the docking and acquisition system, which uses a liquid interface. “Unlike, say, an IntraLase laser where you’re applanating the cornea and flattening it, this laser has a curvature in the head of the acquisition device that mimics the curvature of the cornea,” Dr. Fishkind said. “That then fills the space between that curved head and the cornea with BSS [balanced salt solution].” As a result of this liquid interface he finds that there is no distortion of the cornea. He sees this distinction as important since distortions can make it more difficult to make accurate cuts in the cornea for treating cylinder as well as for paracentesis and incisions. Another unique feature of the system is a suction ring that requires very low vacuum. “It’s low enough that the patient never loses their vision, unlike with the IntraLase, for example,” Dr. Fishkind said. Also key is the acquisition software dubbed 3 DCSI (three-dimensional [3D], confocal, structured illumination). “What this does is it Femto continued from page 11