EyeWorld Asia-Pacific September 2014 Issue

September 2014 8 EWAP FEAturE continued on page 10 Paying the premium lens piper by Maxine Lipner EyeWorld Senior Contributing Writer How much residual error is acceptable? T here was a time when cataract patients were relatively easy to please, willing to wear glasses if necessary following surgery. But what about premium refractive IOL patients today? If you want to maximize satisfaction and minimize visual symptoms, patients nowadays will tolerate surprisingly little residual refractive error, according to Steven C. Schallhorn, MD , professor of ophthalmology, University of California, San Francisco, Calif., U.S.; medical director, Optical Express, Glasgow, U.K.; and in private practice in San Diego, Calif., U.S. In a paper presented at the 2014 ASCRS•ASOA Symposium & Congress, Dr. Schallhorn described just how little room for error there is. “Even 0.5 D of residual astigmatism can lessen the chance that the patient will achieve 20/20 uncorrected vision, decrease patient satisfaction, and increase the chances that the patient will have visual disturbances such as glare and halos,” Dr. Schallhorn said. “That is a big paradigm shift over the last one or two decades when a refractive outcome within 1 D of emmetropia was considered an excellent outcome.” Even a little residual astigmatism may require toric IOL rotation. Source: John Berdahl, MD Tolerance issues “Especially with premium IOLs, there are rising expectations and increasing patient demands; even 0.5 D of astigmatism may not be acceptable to the patient,” Dr. Schallhorn said. “Many clinicians may not realize that certainly 1 D of astigmatism and even as little as 0.5 D can have an impact.” Likewise, as little as 0.5 D of residual sphere can increase patient dissatisfaction with multifocal lenses, Dr. Schallhorn said. “Especially for a multifocal lens, the distance vision needs to be fine-tuned within a very tight refractive range,” he said. John Berdahl, MD , assistant professor of ophthalmology, University of South Dakota, and in practice at Vance Thompson Vision, Sioux Falls, SD, U.S., agreed that there is little room for error in these patients. “For multifocal IOLs, they’re the least tolerant to residual refractive error, so patients generally need to be within at least 0.5 D of sphere and between 0.5 and 0.75 D of cylinder in order to be happy,” he said. Dr. Berdahl finds that patients with accommodating IOLs tend to be more forgiving of residual error. “Accommodative lenses by definition are going to have a more AT A GLANCE • With premium lenses, tolerance for residual sphere or cylinder can be as low as 0.5 D. • Patients with multifocal lenses tend to be the least forgiving of residual error, while those with accommodative IOLs are the most. • When it comes to residual astigmatism, if it is oblique or the patient’s pupil is large, the need for an enhancement may be greater.