EyeWorld Asia-Pacific June 2018 issue

June 2018 50 EWAP REFRACTIVE continued on page 56 17 to 21 days after surgery, after the eye has healed and the lens is in its proper position. Patients get a refraction done to see what the refractive error is. They then have the opportunity to have it corrected in one or both eyes,” Mr. Freeman explained. How it works According to Nick Mamalis, MD , Salt Lake City, “It’s a unique lens in that it’s made out of silicone, but it’s partially polymerized silicone. The small silicone chains have a little moiety on the end of them that is light activated. So when you shine the special UV light from the LDD onto the polymer, it will crosslink. In other words, it will take these partially polymerized ar- eas of silicone, and it will crosslink them and polymerize them in that area. When that happens in one area, the unpolymerized silicone from the areas around it will dif- fuse into that area over the next 12 to 24 hours, changing the thick- ness of the lens and the curvature and changing the power. This is the first truly adjustable lens that we have available in the U.S.” Dr. Mamalis said surgeons can create a hyperopic correction or a myopic correction depending on how the LDD is aimed. “Surgeons can create a hyperopic correction by aiming the device in the center of the lens, crosslinking in that area, and unpolymerized silicone will diffuse in and thicken it in the center,” he explained. “We can create a myopic correction by shin- ing the light more in the periph- ery of the lens, polymerizing it in that area, and the unpolymerized silicone will diffuse peripherally, which will flatten out the center of the lens and create a more myopic refraction. Lastly, we can do an astigmatism correction.” According to John Berdahl, MD , Sioux Falls, South Dakota, cataract surgery with the Light Adjustable Lens is almost identical to traditional cataract surgery, and the delivery of the light is similar to a long YAG capsulotomy. “In other words, it doesn’t require any additional skills beyond what an ophthalmologist is already capa- ble of doing. It just requires the technology and the equipment,” he said. Surgeons said the main advan- tage of the Light Adjustable Lens is the potential for adjustability once it is in the eye. “This advantage is huge because we know that we’re good in average-shaped eyes, but patients who are post-refractive outliers, such as high hyperopes, high myopes, or those who have a fair amount of astigmatism, can be a challenge to treat,” Dr. Berdahl said. “All of these patients will be easily treated with the Light Ad- justable Lens.” Candidates for the Light Adjustable Lens Mr. Freeman said this lens can be implanted in nearly any patient undergoing routine cataract sur- gery. “The most common excep- tion would be a patient who is tak- ing any medications that increase UV light sensitivity. This is uncom- mon,” he said. Kevin M. Miller, MD , Los Angeles, noted that patients who are not eligible for a multifocal lens but who want the best pos- sible uncorrected distance vision outcome or who want a good monovision outcome are good candidates. “These are patients who don’t mind wearing reading glasses and who want to have good distance vision. That’s the mar- ket initially,” he said. “The Light Adjustable Lens will correct up to 2 D of cylinder on the lens, so ±2 D of cylinder, ±2 D of sphere. There’s quite a range of adjustment on the device. Patients’ vision outcomes in the clinical trial were phenom- enal. In fact, they were like LASIK outcomes in terms of uncorrected visual acuity.” Dr. Mamalis added a few more criteria: “Patients must have a clear cornea. Significant corneal scar- ring will disrupt how the laser can treat the lens. Second, the eye must dilate widely enough to treat the entire lens optic.” The wait is over Richard Lindstrom, MD , Min- neapolis, said that he and many other surgeons have been wait- ing for years for an adjustable IOL that does not require surgery on the cornea. “Of approximately 10,000 cataract surgeons in the United States, only about 2,500 are comfortable performing PRK or LASIK. Despite advances in IOL power formulas and biometry with the IOLMaster [Carl Zeiss Meditec, Jena, Germany] and LENSTAR [Haag-Streit, Koniz, Switzerland], we are still in the 70–90% range of patients who are within 0.5 D of target. To have an outstanding outcome, especially in the pre- mium channel, with monovision, multifocal, toric, accommodating, and extended depth of focus lens implants, we need to be within 0.5 D of target and within a few de- grees of the appropriate meridian. We’re not able to get there repro- ducibly, so we would like to have a minimally invasive way to adjust the lens power,” he said. Dr. Lindstrom added that he would love to see more than 90% of patients be within 0.5 D of target. “The recently FDA- approved first-generation RxSight implant hit those targets,” he said. “I think the numbers were 92% within 0.5 D of target, and this was a study that was done with a first-generation product a few years back. RxSight is now working on a second-generation product, which shows promise to move into the middle 90%, which are LASIK-like outcomes. We would like to have LASIK-like outcomes with our cataract surgery, even though it might require a laser adjustment at some time in the postoperative period. Additionally, we would like the adjustment to be minimally Light Adjustable – from page 49