EyeWorld Asia-Pacific March 2011 Issue

What you should know about LAL results • One study found excellent refractive stability with the LAL after implantation • Visual outcomes improved significantly • 100% of patients were within ±1.00 D of the targeted refractive outcome • 88% of eyes were within ±0.50 D of the targeted refractive outcome • 60% of eyes were within ±0.25 D of the targeted refractive outcome Source: Fritz H. Hengerer, MD 24 March 2011 EW REFRACTIVE The Light Adjustable Lens provides an option for cataract patients Source: Calhoun Vision Positive refractive experience with the LAL by Matt Young Senior EyeWorld Contributing Editor LALs manage post-op refractive surprises D espite ophthalmologists’ attempts to do everything they can before cataract surgery to ensure optimal results, the possibility of post-op refractive surprise remains. But surgeons implanting the Light Adjustable Lens (LAL, Calhoun Vision, Pasadena, Calif.) may be less shocked. New research finds that the LAL is as it’s billed: ultraviolet (UV) irradiation can help to adjust the IOL’s refraction after implantation with promising results. “Our results found that the LAL demonstrated excellent refractive stability over time, as well as significantly improved visual outcomes in all patients enrolled in the study,” reported lead study author Fritz H. Hengerer, MD, Center for Vision Science, Ruhr University Eye Hospital, Bochum, Germany. “In addition, the majority of patients (88%) were within ±0.50D of the intended correction, with 68% of eyes having 0.0 D of residual sphere.” The study was published online in April in the Journal of Refractive Surgery . Some concerns remain, such as compliance of patients in wearing UV-blocking sunglasses post-op until the final refractive result is locked in. All did so in this study. In an age when surgeons still fret over the correct IOL calculation, the LAL could be a useful refractive- correcting tool. Fine tuning Dr. Hengerer analyzed 40 eyes of 40 patients that underwent cataract surgery and implantation of the LAL. “It can undergo both spherical and cylindrical power adjustments in the range of ±0.25 to 2.00 D using a controlled application of UV light (365 nm),” Dr. Hengerer noted. “After a period of postoperative refractive stabilization, typically 10 to 21 days, the patient returns for examination and refraction by the surgeon to determine whether adjustment in spherical and cylindrical power is required.” If an LAL power adjustment is required, the lens is irradiated “with a targeted dose of profiled light delivered using the [digital light delivery device] to produce a planned change in the power of the implanted lens … Lenses not requiring a refractive power adjustment are treated with a power neutral dose,” Dr. Hengerer reported. Patients were required to wear UV-protective eyewear at all times until device lock-in after desired refractive correction was obtained. “Once the desired correction was achieved, patients underwent two lock-in procedures that were scheduled 2 to 4 days apart,” Dr. Hengerer reported. “All patients required an initial adjustment of the LAL, whereas 28 required a second UV treatment and none required a third adjustment.” Before surgery, the main refraction (SE) was 0.58±2.29 D, mean sphere was 1.02±2.19 D, and mean cylinder was 0.88±0.66 D. “Ninety-seven percent of patients had a preoperative uncorrected distance visual acuity (UDVA) of 20/60 [6/18] or worse,” Dr. Hengerer reported. “Following the final lock-in, all eyes showed good refractive stability over time. Eighty-eight percent of eyes were within ±0.50 D of the targeted refractive outcome, with 60% within ±0.25 D. One hundred percent of patients were within ±1.00 D of the intended outcome.” All eyes also gained lines of corrected distance visual acuity. As for UDVA, 77% achieved 20/25 (6/7.5) or better, 21% were 20/30 (6/9), and 3% were 20/40 (6/12). “The Calhoun LAL represents a safe and effective means of providing cataract surgery patients with emmetropia,” Dr. Hengerer reported. “If the surgeon has the ability to adjust the refractive power of the IOL after implantation, dealing with any residual refractive error becomes a much less cumbersome and time-consuming process” Dr. Hengerer also wrote that he hopes “to correct multifocal and higher order aberrations with advanced adjusting profiles in the near future”. Sujatha Mohan, MD, associate medical director, Rajan Eye Care Hospital, Chennai, India, looks forward to the launch of the LAL. “It will make a big difference,” Dr. Mohan said. Being able to correct small cylinders post-op will make patients’ vision “more perfect”, she said. “Uncorrected visual acuity could be much better,” she said. “There are some post-op surprises that we could avoid.” Still, she believes the light adjustment would be limited to some extent. She does not believe, for instance, that multifocal IOL technology is suited for light adjustment. “The IOL design in that case is more complicated,” she said. “It needs perfect measurements and centration. It’s going to be more difficult [to add light-adjustable properties].” EW Editors’ note: Dr. Hengerer has no financial interests related to this study. Dr. Mohan has no financial interests related to her comments. Contact information Hengerer: +49 234 299 3101, fritz.hengerer@kk-bochum.de Mohan: +91 044 2834 0500, rajaneye@md2.vsnl.net.in