Eyeworld

FEB 2012

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

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58 EW FEATURE February 2011IOLs February 2012 Electronic IOLs: The future of cataract surgery by Faith A. Hayden EyeWorld Staff Writer Introducing the ELENZA Sapphire AutoFocal IOL, the world's first implantable lens with artificial intelligence I magine offering a cataract pa- tient an IOL powered by its own power cell and computer chip embedded inside. It's rechargeable and fully pro- grammable, allowing the physician to tweak its optical power as the pa- tient's visual needs change. It's an IOL that won't just mimic natural human accommodation, it's de- signed to surpass it. This isn't some lofty overpromise by a science fic- tion-obsessed surgeon; this is the fu- ture of IOL technology. And it's standing on our doorstep. Rudy Mazzocchi is chief execu- tive officer of ELENZA (Roanoke, Va.), the developer of the IOL with the same name. His voice elevates with excitement when speaking of the IOL, calling it the type of inno- AT A GLANCE • ELENZA is the world's first IOL with artificial intelligence • It uses advanced electronics to seamlessly autofocus an optic from far to near without movement • The lens is fully programmable and customizable after implantation vation that "comes along once in a lifetime." "This will probably be the biggest thing I'll ever do," he said. "It's big not only for the ophthal- mology industry, but also represents a pioneering step in the develop- ment of active, programmable human implants." ELENZA combines nanotechnol- ogy, artificial intelligence (neural networks-based memory), and ad- vanced electronics to seamlessly aut- ofocus an optic from far to near without movement. Therefore, the lens doesn't have to rely on precise contact with ciliary muscles to move and accommodate properly. "You've seen windows where you flip a switch and it polarizes the glass and turns it dark. This is a simi- lar concept," said Mr. Mazzocchi. "We're changing the molecular con- figuration of the liquid crystal to alter the optical power of the lens." The IOL builds upon an existing technology from PixelOptics (Roanoke, Va.), which created the world's first electronically focusing prescription eyewear. "Three or 4 years ago, I would have described this as science fic- tion," said Richard L. Lindstrom, M.D., founder and attending sur- geon, Minnesota Eye Consultants, as well as a member of ELENZA's board of directors. "I am also involved with PixelOptics and thought this was science fiction even for glasses. Once that was achieved, the ques- tion became could [the technology] be made small enough to be dupli- cated in an IOL? It turns out that it can be duplicated and is being dupli- cated." ELENZA is an extraordinarily complicated system unlike anything ophthalmology has seen, relying on our individual pupillary response to automatically trigger accommoda- tion between far and near. "It's been proven that the pupil responds to accommodation by get- ting smaller," Dr. Lindstrom ex- plained. "The IOL includes sensors that detect very small changes in pupil size. The pupillary response to accommodation is different from the pupillary response to light in regard to amplitude and how rapidly it oc- curs in response to accommodation." The microscopic rechargeable lithium-ion battery powering ELENZA didn't even exist at the be- ginning of the project, said Andrew Maxwell, M.D., Ph.D., chairman of ELENZA's medical advisory board. Similar batteries have been used in cochlear implants, but the batteries ELENZA uses are the smallest cur- rently known to man. Although Dr. Maxwell estimates the battery itself will have a 50-year cycle-life, it re- quires recharging every 3-4 days. The company is conducting de- mographic studies with select pa- tient populations to create an ideal, noninvasive charging process. The most promising idea is to charge the IOL while the patient sleeps, build- ing a system into a pillow or an eye mask. As anyone with a computer knows, though, electronics fail. Batteries can clunk out. So what happens to the IOL and, more im- portantly, the patient's vision, if something goes awry? "The fail-safe system is the IOL falling back to having only optimal distance vision … defaulting to a monofocal IOL," Dr. Maxwell said. "The patient goes back to needing reading glasses." ELENZA also has a back-up plan for the absentminded patient who may forget the charger while on an extended vacation: a hibernation mode. If not recharged, the IOL de- faults to a monofocal lens and can be rebooted up to 9 months later. Furthermore, the lens is fully programmable and customizable, al- lowing the physician to remotely ad- just the sensitivity and magnitude of the switching point of the add power in the IOL by up to three- quarters of a diopter, based on the particular needs of the patient. "This is the most sophisticated computer chip and algorithm ever used in an implantable medical de- vice," Mr. Mazzocchi said. "Within the first 300 seconds, this IOL is going to learn the specific pupil dy- namics of that patient and cus- tomize its own internal algorithm. As the patient's needs change with time, the physician during a visit can reboot that algorithm and alter its program remotely and noninva- sively. It's a patient-specific, adap- tive, programmable IOL." Far vision—pupil dilation Near vision—pupil constriction Source: Eyemaginations/ELENZA

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