EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78716
March 2012 EW CATARACT 63 "People with previous refractive surgery, keratoconus, pellucid marginal degeneration, and any kind of irregular astigmatism would be outside the norm," he said. Pondering spherical aberration innovation Currently, lens manufacturers "just want to get pretty much in the ball- park," even though everyone proba- bly has a slightly different amount of spherical aberration, Dr. Friedman said. It's understandable, he said, be- cause current technology is still lim- ited. For instance, in order to better customize spherical aberration cor- rection, manufacturers would have to include a range of spherical aber- ration correction for each diopter of say, myopia, for which an IOL cor- rects. That would add up to a huge number of different IOL types, which might not be feasible for a manufacturer, he said. But with the Light Adjustable Lens (LAL, Calhoun Vision, Pasadena, Calif.), which uses light to adjust the IOL power once inside the eye, on the horizon, Dr. Friedman believes more customizable spherical aberration correction is achievable. The most customized approach available currently may be to take a wavefront map of the cornea and choose one of the existing aspheric IOLs to as closely as possible com- pensate for a patient's spherical aber- ration. It's an approach that some doctors use, Dr. Friedman said. Current aspheric IOL technol- ogy is making quality of vision bet- ter overall, Dr. Beiko added. "As a group, you're making things better," he said. "But we know not everybody's spherical aberration is the same." As for future innovation, it's im- portant to remember that spherical aberration isn't always bad, Dr. Beiko said. Rather, it's important to manipulate spherical aberration to achieve a desired visual outcome, he said. "The next step is to actually ma- nipulate those values to determine whether we want to target the sharpest vision or a range of vision," Dr. Beiko said. "For instance, with presbyopic LASIK procedures, a lot is based on inducing spherical aberra- tion in the cornea, which makes dis- tance vision fuzzy but improves the range of vision. You can play around with these numbers." EW Editors' note: Dr. Beiko has financial interests with AMO. Dr. Friedman has no financial interests related to this article. Contact information Beiko: 905-687-8322, georgebeiko@hotmail.com Friedman: 650-324-0056, njfmd@pol.net