Eyeworld

EW FEATURE 52 Products that could change how you practice • September 2018 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. by Ellen Stodola EyeWorld Senior Staff Writer/Digital Editor The lens is FDA approved but not yet commercially available in the U.S. T hough FDA approved, the Light Adjustable Lens (LAL, RxSight, Aliso Viejo, California) is not yet cur- rently 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 expe- rience with the lens in clinical trial, how it works, and for what correc- tions 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 refractive error. "The clinical trial results were remarkable," he said. "The amazing thing for me about the clinical trial was patients having their blurry vision clear up after the light treat- ment." 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 mono- mers 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 periphery of the lens and the monomers 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 astigmatism 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 monofocal lens implant," he said. "The differ- ence occurs postoperatively in that at 2–3 weeks postoperatively, 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 endpoint." 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 are identical to typical cataract surgery." During the trial, Dr. Chang im- planted the first 16 LALs in the U.S. as a Phase 2 investigator. "The ad- justment and lock-in procedures are quite straightforward. Like a YAG capsulotomy, they are performed in the office with a slit lamp delivery system using a contact lens to focus the treatment," he said. Dr. Chang said that refractive accuracy has improved thanks to advances such as intraoperative aberrometry, improved biometry, and better calculation methods, but these are all still different methods for IOL power prediction. "They im- prove the mean but don't eliminate the standard deviation, especially in challenging eyes post-refractive sur- gery, or with unusual keratometry or axial lengths," he said. Dr. Chang added that the EUREQUO study reported refractive results from more than 280,000 patients from 100 clinics. This "real world" data set reported that 27% of eyes failed to land within 0.5 D of the spherical refractive target. 1 "Although I currently employ corneal topography and wavefront aberrometry, swept-source OCT biometry, multiple advanced formulae, intraoperative aberrom- etry, and digital intraoperative What to know about the Light Adjustable Lens First patient implanted in the FDA PMA trial after all treatment has been done. The patient is a 70-year-old male with UCDVA 20/12 and UCNVA J2. Source: Kevin Waltz, MD

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