EyeWorld India December 2018 Issue

December 2018 8 EWAP FEATURE What to know about the Light Adjustable Lens by Ellen Stodola EyeWorld Senior Staff Writer/Digital Editor AT A GLANCE • The LAL is FDA approved but not yet commercially available in the U.S. It is approved for ±2 D of sphere and 0.75–2 D of astigmatism. • It uses light exposure following implantation to adjust refraction, and once the desired refraction is achieved, it is “locked in.” • In the trial, 92% of LAL eyes were within 0.5 D of target. The lens is FDA approved but not yet commercially available in the U.S. T hough U.S. Food and Drug Administra- tion (FDA) approved, the Light Adjustable Lens (LAL, RxSight, Aliso Viejo, California) is not yet currently available in the U.S. Robert Maloney, MD, Los Angeles, John Doane, MD, Leawood, Kansas, David F. Chang, MD, Los Altos, California, and Kevin Waltz, MD, Indianapolis, discussed their experience with the lens in clinical trial, how it works, and for what corrections it has approval. LAL in the clinical trial Dr. Maloney said that with this lens, the patient has routine cataract surgery, and several weeks postop, instead of prescribing spectacles, the surgeon exposes the LAL to a precise pattern of light that changes the shape of the lens to correct the residual refrac- tive error. “The clinical trial results were remarkable,” he said. “The amaz- ing thing for me about the clini- cal trial was patients having their blurry vision clear up after the light treatment.” He added that “it was like magic to them.” The hardest part of the clinical trial, Dr. Maloney said, was to tell the patients that they couldn’t have the LAL in the second eye, since it was a unilateral eye study. “The concept is the lens can change its three-dimensional shape after being exposed to light,” Dr. Doane said. “Particles or monomers can easily migrate within the lens and do so when exposed to ultraviolet light.” He added that to flatten the center of the lens to treat myopia, you would expose the light to the pe- riphery of the lens and the mono- mers would migrate there, and subsequently thicken the periph- ery of the implant and flatten the center. “The exact opposite occurs if we want to treat hyperopia,” he said. “We expose the center of the lens, the monomers migrate to the center and thicken the center of the lens, and increase the radius of curvature, resolving the hyperopic refractive error.” Variations on this then can be done for astigma- tism or any shape desired. Dr. Doane described his expe- rience in the clinical trial as “very straightforward.” “The surgery is done exactly like we do with a standard mono- focal lens implant,” he said. “The difference occurs postoperatively in that at 2–3 weeks postopera- tively, we refract the patient.” If the patient’s refraction is not ideal the doctor can place them behind the light delivery system of the RxSight device and expose them to around 90 seconds of light to “adjust” their refractive state to the desired target. After this, Dr. Doane said the patient should be rechecked in 4–5 days. “If the patient likes the unaided vision, we can ‘lock in’ this refraction,” he said. “If not, we can make a second adjustment, wait 4–5 days, and lock in their preferred end- point.” After the IOL implantation, and until about 3 days after the final light exposure, the patient wears specific UV range blocking glasses, Dr. Doane said. “Other than that, the drops and postop First patient implanted in the FDA PMA trial after completion of all treatments. The patient is a 70-year-old male with UCDVA 20/12 and UCNVA J2. Source: Kevin Waltz, MD