Eyeworld

EW REFRACTIVE 128 March 2018 Refractive editor's corner of the world by Michelle Stephenson EyeWorld Contributing Writer more in the periphery 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 capable of doing. It just requires the technol- ogy 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 Adjustable 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 exception would be a patient who is taking any medications that increase UV light sensitivity. This is uncommon," he said. Kevin M. Miller, MD, Los Ange- les, noted that patients who are not eligible for a multifocal lens but who want the best possible 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 market 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 phenomenal. Surgeons discuss newly approved lens that can be adjusted postoperatively I n November 2017, the U.S. Food and Drug Administration (FDA) approved the RxSight (Aliso Viejo, California) Light Adjustable Lens and the Light Delivery Device (LDD) for patients with 0.75 D or more of pre-existing astigmatism. This is the first FDA-ap- proved lens that can be adjusted postoperatively to improve uncor- rected visual acuity. FDA approval was based on results of a U.S. randomized, pivotal study comparing the Light Adjust- able Lens to a commercially avail- able monofocal lens in 600 patients with pre-existing astigmatism at Light Adjustable Lens implant technology I have been so excited about light adjustability of intraocular lens implants to help our pa- tients achieve the visual outcomes they are looking for without having to perform corneal refractive surgery. As an investigator in the FDA monitored Light Adjustable Lens it was impressive to witness the patients' explanation of crisp visual outcomes and high satisfac- tion. We thought this was due to achieving precise refractive outcomes like we have never seen without having to touch the cornea through a corneal laser enhancement. We know that corneal refractive surgery induces a certain amount of multifocality that is typically quite ac- ceptable. It should not be surprising that image quality can be impressive with light adjustable lenses that prevent the need for corneal laser adjustments. We know that current IOL results are not as accurate as we would like because we have to estimate the final effective lens position along with variables such as posterior corneal cylinder and changing anterior corneal cylinder due to incisional healing. To allow all those healing variables to settle into their final stable state then adjust the final lens power is a game changer for cataract surgery visual outcomes. Many think that the reason premium IOLs have not taken off at the rate that has been expected is because some physicians don't want to do PRK and LASIK enhancements, and pa- tients do not want corneal refractive surgery to fine tune their vision either. To bring the ease and accuracy of light adjustability into the cataract surgery arena is a disruptive innovation that we have all been waiting for. In addition, as far as patient education goes, we currently have to paint "word pictures" in preoperative discussions on visual options patients have for their lifelong vision decision. With light adjustability, this discussion and decision are done postoperatively so that we can show them their various refractive options, then they make an informed decision based on the corrected vision options presented to them. Light Adjustable Lens technology has the potential to revolutionize the accuracy of uncorrected vision after cataract surgery. We thank Roy Freeman of RxSight along with Nick Mamalis, MD, John Berdahl, MD, Kevin Miller, MD, and Richard Lindstrom, MD, for their teachings on this exciting new technology. I hope you enjoy this article as much as I did. Vance Thompson, MD, Refractive editor 17 investigational sites. Patients receiving the Light Adjustable Lens followed by light treatment with the LDD achieved uncorrected visual acuity of 20/20 or better at 6 months postoperatively at approxi- mately twice the rate of the patients who received a monofocal lens. Additionally, 91.8% of Light Adjustable Lens patients achieved a result that was within 0.50 D of target manifest refraction spherical equivalent, which is similar to the refractive accuracy seen in recent LASIK studies. All of the study eyes had a best corrected visual acuity of 20/40 or better at the 6-month postoperative visit. The approved device allows correction of up to 2 D of postoperative sphere and/or –0.75 to –2 D of residual postoperative refractive cylinder. "We were thrilled to receive FDA approval and are grateful to all those who were involved in this effort," said Roy Freeman, senior director of marketing for RxSight. "We are currently working with the FDA on a post-approval process, as well as building the infrastructure to support a global launch. We will make an announcement sometime this year as far as launch timing." According to Mr. Freeman, the adjustment is done with UV light, and while there are a lot of light treatment profiles that can be performed with the LDD, RxSight is currently approved for correcting sphere and cylinder. "This is done 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 areas 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 diffuse into that area over the next 12 to 24 hours, changing the thickness of the lens and the curvature and changing the power. This is the first truly adjust- able 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 dif- fuse in and thicken it in the center," he explained. "We can create a my- opic correction by shining the light

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