Eyeworld

EW CATARACT 18 January 2015 Device focus by Michelle Dalton EyeWorld Contributing Writer except one," he said. By manipulat- ing the echelette, AMO "can get a defocus curve that's fairly flat from infinity in, to about 1 m." The Symfony "may be a step in the right direction," but may not give patients a wide enough amplitude of accommodation, said Dr. Mamalis, who thinks a "totally different design" will be needed. "[It may be] a dual optic lens or a lens that changes the shape of the optic when you accommodate with a material, like silicone in the middle of it. That's going to be the future," Dr. Mamalis said. Dr. Packer said distance and intermediate "will be equivalent and greater" than current lenses, but people with these lenses "will still need a lower-powered pair of reading glasses." However, the elim- ination of halos may be worth that trade-off, he said. The lens may be "much more forgiving in terms of distance vision," meaning someone who is "almost 1 D hyperopic post-surgery will still have clear distance vision," Dr. Packer said, although that person would lose intermediate vision. "In that example, the lens would function more like a monofo- cal, but you have a whole diopter of pretty much flat defocus curve. It'll be more forgiving in terms of the IOL power calculation for distance," he said. EW Editors' note: Drs. Alio, Mamalis, Packer, and Werner have financial interests related to their comments. Dr. Cummings has no financial interests related to his comments. Contact information Alio: jlalio@vissum.com Cummings: abc@wellingtoneyeclinic.com Mamalis: nick.mamalis@hsc.utah.edu Packer: mark@markpackerconsulting.com Werner: liliana.werner@hsc.utah.edu spherical aberration, Dr. Cummings said. AcuFocus (Irvine, Calif.) has begun studies on "a small aper- ture hydrophobic acrylic IOL, a single-piece lens with a centrally located opaque annular mask with the same principle as the compa- ny's KAMRA corneal inlay," said Dr. Werner, associate professor and co-director of the Intermountain Oc- ular Research Center, John A. Moran Eye Center. Monocular implanta- tion provided a "continuous, broad range of vision resulting in excellent visual acuity across all distances," although results were in only 11 patients and only through 6 months of follow-up. For now, the "holy grail" of true accommodation in an artificial lens does not exist—but Dr. Mamalis is optimistic that with the new tech- nologies being developed here and overseas, it's only a matter of time. Extended range of vision lens There is "pretty good data" from European studies on the Tecnis Symfony IOL (Abbott Medical Optics, Abbott Park, Ill.), "including defocus curves that show about 1 D of accommodation, which is similar to the Crystalens or Trulign [both Bausch + Lomb, Bridgewater, N.J.]," said Mark Packer, MD, president of Mark Packer MD Consulting. But the Tecnis' mechanism of action "is much more conventional," as it is a single diffractive. "It's as if you took a multifocal lens and eliminated all the rings The lab of Dr. Mamalis and Liliana Werner, MD, PhD, uses research eyes and works with all the newer technology lenses, but "it's frustrating because none of these technologies are available for our patients here in the United States," Dr. Mamalis said. Ideally, he'd like to help streamline the U.S. regulatory approval process "to get the new technology available" in a shorter period of time. One of the biggest challeng- es today is that most lenses will improve best corrected visual acuity (BCVA), "but we still haven't nailed the refraction. We still have issues with IOL predictions and accuracy, and there are some patients who will develop posterior capsule opacification (PCO) after surgery," said Arthur B. Cummings, MB ChB, FCS(SA), MMed(Ophth), FRCS(Edin), consultant ophthalmol- ogist at the Wellington Eye Clinic and Beacon Hospital, Dublin. EDOF lenses Several EDOF lenses are based on spherical aberrations, Dr. Cummings said. The MiniWell (Sifi Medtech, Aci Sant'Antonio, Italy) is the first preloaded, progressive, multifocal, aspheric IOL for mini incision able to offer high visual performance compared to the conventional diffractive IOLs. Currently the lens is undergoing a 2-armed study, and "initial results seem quite promising," he said. Hoya (Chino Hills, Calif.) is also developing an EDOF lens based on EyeWorld spoke to experts around the world about the latest new technology lenses (part 1 of 2) N umerous new IOLs are under development and in clinical trials, all with the hope of treating presbyopia through multifocality or true accommoda- tion. With estimates of market share for lenses currently on the market at about 5% to 6%, there is no arguing that clinicians would benefit from having newer lenses available, in both cataract and refractive markets. One major barrier to a greater market rate is that artificial accom- modation has failed in the lenses currently available, experts say. In Europe, several of the newer tech- nology lenses are designed for sulcus implantation—not intracapsular— which may be the eventual key to a truly accommodating IOL. (Next month, EyeWorld will delve into more new technology lenses, includ- ing the latest on trifocal implants.) Yet even the experts agree confusion remains over the termi- nology. "What constitutes a new technology lens? Extended depth of focus (EDOF) or true accommo- dation?" said Nick Mamalis, MD, professor of ophthalmology, co-di- rector of the Intermountain Ocular Research Center, and director of ocular pathology, John Moran Eye Center, Salt Lake City. He thinks the EDOF lenses are more of a refine- ment than a new technology. On the other hand, EDOF IOLs "are becoming an opportunity based on different optical factors," which should qualify them for a "new technology" designation, said Jorge L. Alió, MD, PhD, professor and chairman of ophthalmology, Miguel Hernandez University, Alicante, Spain, and medical director of Vissum Corporation, Spain. "This EDOF is incorporated into some technologies … The Mplus [Oculen- tis, Berlin] has an increased depth of focus based on paraxial asphericity that works very well as an added value to the IOL near vision power." The Mplus is currently available in Spain and is "becoming exten- sively used in the private sector." New technology IOLs: What's here and what's coming For more on new IOL technology, including the Tecnis Symfony IOL, see the "Refractive editor's corner of the world" on page 26, which features coverage from the 2014 APACRS meeting in Jaipur, India.

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