Eyeworld

EW CATARACT 42 June 2018 by Rich Daly EyeWorld Contributing Writer Device focus "The advantage of that is there's great centration of the optics with the capsulotomy so you don't get lens tilt, decentration, or a lot of things that could be uncomfortable if you don't have a perfect capsulot- omy," Dr. Waltz said. Manual capsulotomies are frequently too small, off center, or irregular, which can affect lens positioning. Dr. Waltz said the device has fit well within the clinical workflow, with it taking the same or less time as other approaches. Another key component of the device is that it allows patients to interact with the surgeon during surgery by fixating on a surgical light, which allows centering the device and the capsulotomy on the visual axis. Surgeons can use the resulting visual landmark during surgery to align the IOL within the capsulot- omy. Other advantages Surgeons using the device have identified another, unintended ben- efit, Dr. Sretavan said. In the last step where suction is reversed, ophthalmic viscosurgical device is reintroduced along with a little balanced salt solution and creates a subcapsular fluid wave. Surgeons have reported this helps hydrodissection and also seems to remove lens epithelial cells under the capsule that they otherwise need to remove using other methods. "Zepto appears to be more than just a capsulotomy device; it appears to also help in other steps of surgery such as hydrodissection and cortical cleanup," Dr. Sretavan said. Dr. Chang's research on the device has found the simultaneous use of suction seems to create a mi- croscopic curling of the cut capsulo- tomy edge that imparts greater tear resistance. 1 "Unlike with the femtosecond laser, there is no cutting or dis- turbance of the underlying cortex because only tissue in contact with the thin nitinol edge will be cut," Dr. Chang said. "Therefore, hydro- dissection and cortical removal are no different than with a manual capsulorhexis." The strength of the capsulot- omy edge is important with more Reports of early use of Zepto continued on page 44 The Zepto capsulotomy system, including handpiece and control console Zepto's manufacturing protocols aim to avoid nitinol capsulotomy rings with imperfections (top left) and produce only rings that enable 360-degree even energy delivery (top right); a Zepto capsulotomy with 360-degree, slightly rolled-up, and strong capsulotomy edge from cadaver eye (bottom left); surgical photo showing Zepto capsulotomy after lens phaco and cleanup (bottom right) Source: David Sretavan, MD Surgeons share pearls and surgical results for the capsulotomy device approved for the U.S. market in 2017 T he latest device approved to create capsulotomies has provided cataract surgeons with a helpful option and some unexpected benefits. The Zepto capsulotomy system (Mynosys Cellular Devices, Fre- mont, California) uses a handpiece attached to a laptop-sized console to create a "phase transition" of water molecules trapped between the device and the capsule to create capsulotomies, said David Sretavan, MD, co-founder of Mynosys Cellular Devices. "What's unique is that the tissue cutting action is delivered by a ring, so the capsulotomy happens 360 degrees at the same time," Dr. Sretavan said. "Surgeons using Zepto have identified its unique capsulo- tomy action as beneficial in high pressure cataract situations where it relieves pressure and completes the entire capsulotomy at the same instant." The device involves three steps: creating suction so the cutting ele- ment is opposed tightly against the capsule surface; directing the energy to the capsule ring; and reversing suction at the end of the procedure to float the Zepto tip off the capsule. The U.S. Food and Drug Admin- istration granted 510(k) clearance for the Zepto in June 2017. Elizabeth Yeu, MD, assistant professor, Eastern Virginia Medical School, Norfolk, Virginia, has used the device for 3 months and found getting comfortable with it was relatively easy. "I love having the ability to create a standardized, well-centered capsulotomy in the OR and saving the time that it takes me to create the same step in the laser room with femtosecond laser assistance," Dr. Yeu said. Dr. Yeu sees its ability to auto- mate the capsulotomy as a boost to refractive outcomes. David F. Chang, MD, clinical professor, University of California, San Francisco, has used the Zepto device since the 2016 FDA clinical trial and said the learning curve to master its nuances is about 10 cases. Dr. Chang agreed that efficien- cy is one major advantage of the device. Surgeons merely use the disposable Zepto tip in lieu of cap- sule forceps in the normal surgical sequence. "This means that you can em- ploy Zepto after iris retractors have been inserted for a small IFIS pupil, for example," Dr. Chang said. Kevin Waltz, MD, president, Ophthalmic Research Consultants, Indianapolis, has used the device since 2016 and found it has provid- ed more reliable capsulotomies than manual techniques.

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