EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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February 2011 December 2012 Toric IOLs Dr. Koch began examining posterior corneal astigmatism when he noticed that some patients had unexpected results with toric IOLs. Patients who had with-the-rule astigmatism were being overcorrected, while patients who had against-the-rule astigmatism were undercorrected. ���It has a huge impact on my decision making now in patients who are seeking astigmatic correction during cataract surgery,��� Dr. Koch said. ���It���s completely changed everything I���m doing with regard to both relaxing incisions and with regard to the selection of toric IOLs. ���I have backed off on toric IOL power in patients who have withthe-rule astigmatism and conversely ramped it up for those patients with against-the-rule. For example, for someone who has 1 diopter withthe-rule astigmatism, I will not put a toric IOL in because I am likely to overcorrect him and leave him with against-the-rule astigmatism,��� he said. He cited a long-term study by K. Hayashi and colleagues that followed patients��� astigmatic change after undergoing 3-mm clear corneal temporal incisions. The study also had a control group that did not undergo cataract surgery. Researchers found that both groups had a comparable change of against-the-rule shift after more than 10 years. ���You would think that a corneal incision temporarily might weaken the cornea such that the cornea would not steepen along the horizontal meridian over time. But in fact it does,��� Dr. Koch said. ���So in planning for our patients, I believe that we need to leave our patients a little bit on the with-the-rule side in order to compensate for the fact that they���re going to drift to against-therule over time. This will provide them with better uncorrected acuity over a much longer period of time and perhaps serve them well for 20 or more years.��� EW corneal astigmatism to total corneal astigmatism. J Cataract Refract Surg. 2012 Oct 12. [Epub ahead of print] 27 Contact information Wang: 713-798-7946, liw@bcm.tmc.edu Koch: 713-798-6443, dkoch@bcm.tmc.edu She Googled it. le 53% of American adults age 65 and older use the internet and 30% of websites contain inaccurate medical information, according to recent studies. Guide your patients to websites with high levels of medical accuracy. www.eyesurgeryeducation.org References 1 Hayashi K, Hirata A, Manabe S, Hayashi H. Long-term change in corneal astigmatism after sutureless cataract surgery. Am J Ophthalmol. 2011 May;151(5):858-65. 2 Koch DD, Ali SF, Weikert MP, Shirayama M, Jenkins R, Wang L. Contribution of posterior Editors��� note: Dr. Wang has financial interests with Ziemer. Dr. Koch has financial interests with Ziemer, Alcon (Fort Worth, Texas), Abbott Medical Optics (Santa Ana, Calif.), and OptiMedica (Sunnyvale, Calif.). EW REFRACTIVE SURGERY Sponsored by