EyeWorld Asia-Pacific September 2011 Issue

20 September 2011 EW REFRACTIVE One approach to correcting presbyopia involves lens softening with the femtosecond laser. Pictured here: Femtosecond laser pulses in a living human lens, creating bubbles immediately after placement in a waffle pattern Source: Ronald R. Krueger, MD New frontiers, from lens softening to scleral plasticity enhancement techniques I n addition to more traditional approaches to correcting presbyopia, such as lens- or corneal-based technology, an innovative frontier is emerging. Inroads are being made in everything from femtosecond lens softening to enhancement of scleral plasticity. EyeWorld took a closer look at some of these to see how they might eventually civilize presbyopic territory. Smithing away at lens softening One innovative new approach is using the LensAR femtosecond laser (Winter Park, Fla., USA) to soften the lens nucleus. The concept here is to place femtosecond pulses in the nucleus, according to Ronald R. Krueger, MD, medical director of refractive surgery, Cole Eye Institute, Cleveland, Ohio, USA, and professor of ophthalmology, Cleveland Clinic. “The lens nucleus is then softened as compared to the harder nuclear state that might have been there before, and that would allow for more flexibility of the crystalline lens,” Dr. Krueger said. With the technique, the laser will focus very localized pulses along any specific geographic pattern in whatever volume needed. “We don’t have to cut through the anterior part of the lens to get in the middle of it—the laser goes right to the middle,” Dr. Krueger said. “We can put pulses in any number of different patterns in order to try and make the lens softer so that it’s more flexible.” Results so far, however, have been modest and somewhat unpredictable. “We’ve shown that we could make the lens more flexible experimentally, but in treating patients we have not seen any consistent return of that accommodative mechanism,” Dr. Krueger said. “What we have seen is that we can put the laser pulses inside the lens without having a cataract form from them.” There have been a few cases where the technique has shown promise. “We have seen a few cases where we got 1.5 D or so of potential accommodation change with objective measurement,” Dr. Krueger said. “But many other cases we haven’t seen any change.” Investigators are now working on the patterns to try and come up with one that they hope will work the most effectively. Dr. Krueger thinks that successes that LensAR has had of late in using the femtosecond technology for cataract surgery AT A GLANCE • Lens softening with the femtosecond laser hopes to restore flexibility to the crystalline lens • Liquid crystal eyeglasses change power at the press of a button • Scleral expansion bands purport to help the posterior zonules work in changing lens shape • LaserACE restores the plasticity of the sclera, increasing the efficiency of the ciliary body The pioneer spirit: Unmapped presbyopia correction territories by Maxine Lipner Senior EyeWorld Contributing Editor will provide the financial foundation to continue working on accommodation restoration. “In time, I think that we will eventually be able to solve this issue,” he said. D. Rex Hamilton, MD, assistant clinical professor of ophthalmology, and director, UCLA Laser Refractive Center, Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Calif., USA, is hopeful that this may eventually prove successful. “I think that it could be a potentially huge treatment because there are no incisions and it’s minimally invasive in terms of risk of infection,” he said. His one concern is making sure that the procedure does not heighten the risk of cataract development.