Eyeworld

2 | SUPPLEMENT TO EYEWORLD | NOVEMBER 2019 Douglas Koch, MD Astigmatism fundamentals astigmatism, whereas when managing astigmatism in the operative setting we need to look at corneal astigmatism," he said. To achieve optimal results, Dr. Garg said that sur- geons must manage the ocular surface aggressively. Incorporating toricity in presbyopic patients Dr. Garg educates patients about lens options through videos, vision simulators, and extensive discussions. He uses patients' questionnaire responses to guide them to the correct lens. Patients may expect spec- tacle independence, regardless of their IOL, and often com- pare their results with others' outcomes. "I explain that each person's eyes and situation are independent, and my job is to help the patient choose the right lens for his or her partic- ular situation," he said. He discusses femtosecond lasers to treat low amounts of astigmatism but said he grav- itates toward toric IOLs for astigmatism greater than 1 D. "We are lucky that there are several models of pres- byopia-correcting IOLs that now incorporate toric correc- tion," Dr. Garg said. He follows the Bay- lor nomogram and tries to undercorrect with-the-rule astigmatism and overcorrect against-the-rule astigma- tism. "I also look at the total keratometry reading from an anterior segment tomography device as well as the total corneal refractive power from a swept-source optical coher- ence tomography biometer to give me a better sense of what is going on with posterior cor- neal astigmatism," he said. Dr. Garg aims for the lowest amount of residual astigmatism possible (less than 0.5 D), preferring to leave patients with a very small amount of astigmatism and flip the axis rather than leaving a larger amount of astigmatism without flipping the axis. "You have to be metic- ulous and aggressive when managing astigmatism in patients opting for presby- opia-correcting IOLs," he said. Developing best practices Surgeons need to develop best practices to surgically manage astigmatism in cataract pa- tients because it is important to be consistent and meticu- lous, Dr. Garg said. The ocu- lar surface must be optimized, and there must be agreement between preoperative diag- nostic tests. Furthermore, painstaking technique and alignment are important to ensure predictable outcomes, he said. "Certainly, not all cases go as planned, and it is important to understand strategies to fig- ure out what went wrong and how to remedy it," he said. n Reference 1. ASCRS Clinical Survey, 2018. Dr. Garg is vice chair and medical director, Department of Oph- thalmology, Gavin Herbert Eye Institute at the University of California, Irvine, and chair of the ASCRS Young Eye Surgeons Clinical Committee. He can be contacted at gargs@uci.edu or 949- 824-0327. continued from page 1 Understanding preop and postop astigmatism management T o surgically manage astigmatism effective- ly, surgeons need to develop a consistent set of diagnostic and surgical best practices. Preoperative assessments Douglas Koch, MD, stressed that a healthy ocular surface is necessary for accurate and repeatable measurements. He prefers a biometer with multi- ple LED rings and, to confirm the steep meridian, a corneal topographic map, ideally one with Placido mires, to aid in evaluating the quality of the ocular surface. The refraction sometimes also offers important informa- tion. "First pointed out to me by Robert Cionni, MD, some patients seem to have much more with-the-rule (WTR) astigmatism in their topogra- phy than in their glasses, or there may be more against- the-rule (ATR) in the glasses. Those could be signs that the toric toolbox: Building skills and strategies to surgically manage astigmatism continued on page 3

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