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58 EW SHOW DAILY Sunday, April 21, 2013 Meeting Reporter Managing astigmatism a more precise art form By Michelle Dalton EyeWorld Contributing Writer M ost physicians believe arcuate femtosecond incisions will be a moderate to very significant improvement over manual incisions, according to an audience response system question; another 54% believe flipping the axis to ensure a low residual cylinder is preferable to leaving the axis alone in order to ensure a lower residual cylinder. These and other astigmatism correction trends were discussed during an Abbott Medical Optics (Santa Ana, Calif.) sponsored luncheon called "New Technologies and Techniques for Tackling Astigmatism: Diagnostic, Intraoperative, and Postoperative Management." Eric D. Donnenfeld, MD, reported that only 25% of surgeons perform a limbal relaxing incisions (LRIs); on average, though, "in a study of 6,000 patients, 18% has more than 1.5 D of astigmatism, and 53% had 0.75 D or more. Many patients will not tolerate even 0.5 D of astigmatism, especially our premium lens patients." There are two LRI calculators available online, he said, and using a femtosecond laser elevates arcuate incisions to a more precise form, he said. Steven C. Schallhorn, MD, analyzed 30,000 eyes (15,000 patients) to determine the percentage of patients with 20/20 postoperative vision and residual astigmatism who reported they were "very satisfied" with the procedure. For those with no residual astigmatism, 75.5% were very satisfied. Those numbers start to drop once with higher amounts of astigmatism, he said, to 70.6% at 0.25 D, 59.4% at 0.5D, 50.8% at 0.75D, and 35.1% at 1.0D. "The number of dissatisfied patients grows exponentially with each quarter diopter of residual astigmatism," he said. A small study on AMO's iDesign (n=274 eyes/181 patients) evaluated patients with an average preop VA of –3.92 D and 1.17D of astigmatism. Postoperatively, Dr. Schallhorn said 63.1% were within 5 degrees, "so there was in essence no axis flip," he said. "What I found most surprising was that even a quarter diopter of residual astigmatism was very significant for a good number of these patients." Iqbal "Ike" K. Ahmed, MD, discussed five common myths about toric IOLs: Never flip the axis, being within 10 degrees of target is acceptable, marking the eye is not important, moving incisions around will give an acceptable outcome, and all toric calculators are equal. "Flipping the axis is fine with me," he said. "If patients with high degrees of preop astigmatism can tolerate an axis flip, those with lower degrees will tolerate it as well." Other pearls: improving surgical accuracy happens by getting accurate K readings; superior incisions produce higher surgically induced astigmatism than supratemporal, which are still higher than temporal. "Scleral limbal incisions create less SIA," he said. EW Editors' note: This event was sponsored by Abbott Medical Optics. continued from page 57 Matossian maximizes the patient's ocular surface, including the use of artificial tears four times a day for all patients. She believes this gets patients comfortable using eye drops, which is helpful once they have to start surgical-related medication. She also will prescribe other medications for dry eye if the patient needs them. Panelists speak at the "New Technologies and Techniques for Tackling Astigmatism: Diagnostic, Intraoperative, and Postoperative Management" program. Dr. Matossian addressed the importance of accurately calibrated keratometry and preoperative marking of patients. Other presenters at the session presented case studies and discussed postop management for refractive IOL patients. EW Editors' note: This event was supported by a grant from Abbott Medical Optics (AMO, Santa Ana, Calif.).