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26 | EYEWORLD DAILY NEWS | MAY 18, 2020 DAILY NEWS ASCRS VIRTUAL ANNUAL MEETING difficulty in calculating effec- tive lens position (ELP). However, Dr. Wang noted that a wide range of approach- es and formulas have been developed, and she specifi- cally mentioned the ASCRS Post-Refractive IOL Calcula- tor, intraoperative wavefront aberrometry (ORA, Alcon), and formulas embedded in biome- ters as tools surgeons can use. She discussed the ASCRS Post-Refractive IOL Calcula- tor, available on the ASCRS website, and said to use as many formulas as possible on the calculator. Select the IOL power based on the consensus of multiple methods, and rely more on average IOL power and Barrett True K and OCT. With ORA, Dr. Wang said this is primarily a "final check" to confirm the pre-selected IOL power. If ORA suggests a dif- ferent IOL power greater than or equal to 1 D, she suggested changing the pre-selected pow- er by 0.5 D. Dr. Wang's presentation also highlighted IOL selection with aspheric IOLs, toric IOLs, and multifocal and EDOF IOLs, and she shared several case presentations. Editors' note: Dr. Hill has financial interests with Alcon, Haag-Streit, Omega Ophthalmics, Optos, Carl Zeiss Digital Innovations, and LENSAR. Dr. Sandoval has financial interests with Alcon and Johnson & Johnson Vision. Dr. Wang has financial interests with Alcon and Carl Zeiss Meditec. Dr. Vann has financial interests with Alcon. Hill-RBF do better for minus power IOLs. The Barrett Universal II formula is available on multi- ple biometers, as well as the APACRS website. The Hill-RBF method, which determines IOL selection based on artificial intelligence, is available on the LENSTAR LS900 biometer (Haag-Streit), the RBF calcu- lator website, and the ASCRS website. Dr. Vann presented on high axial hyperopia, which he said can lead to poor refractive outcomes. His presentation shared data comparing several formulas to look at wheth- er the latest-generation IOL formulas perform better. These latest-generation IOL formu- las include more variables, he noted. During the course, Dr. Wang presented on prior refractive surgery. This poses several challenges in corneal refractive power estimation, Dr. Wang said, in that it's more difficult to determine anterior corneal power, and standard methods of calculating net corneal refractive power are in- accurate. There is also greater who selects the IOL power calculation method(s) to be used, offers guidance, and keeps the process current. A final validation of the measure- ment process also needs to be done, and the person in charge selects/confirms the IOL power to be implanted and sets stan- dards for when patients return for repeat testing. This person would also need to oversee the ongoing process of outcomes tracking and, when necessary, initiate lens constant optimi- zation. He said the surgeon is really the person who needs to be in charge of this process in his or her practice. Dr. Sandoval's presentation focused on high axial myopia, first noting that current formu- las for long eyes tend to select IOLs of insufficient power. In terms of an approach to the long eye, Dr. Sandoval presented that the Barrett and Hill-RBF give similar results, and probably do the best for the high to extreme axial myope. The Wang-Koch axial length modification also does a very good job for the high to extreme axial myope, she presented, but Barrett and by Ellen Stodola Editorial Co-Director D uring a course on IOL power selection, presenters shared considerations for best practices. Presenters in the session included Warren Hill, MD, Mesa, Arizona, Helga San- doval, MD, Charleston, South Carolina, Robin Vann, MD, Durham, North Carolina, and Li Wang, MD, PhD, Houston, Texas. Topics covered included the role of the surgeon, accuracy standards, validation criteria, IOL power selection methods, high axial myopia and high axial hyperopia, toric IOLs, and prior refractive surgery. Dr. Hill presented on the role of the surgeon in IOL power selection. Surgeons are primarily being judged by both patients and peers based on refractive outcomes, he noted, but there are a number of un- anticipated surgical outcomes that can occur. These could include things like posterior capsular tear/vitreous pro- lapse, radial anterior capsular tears, IOP spikes, postop corne- al edema, incision leak, cystoid macular edema (CME), iris damage, retained lens frag- ments, undetected higher order aberrations, TASS, or endoph- thalmitis. But Dr. Hill said that an incorrect IOL power is the most common unanticipated outcome for any surgeon's practice. So, who is in charge of this lens selection process? Dr. Hill noted that it should be the most knowledgeable person on the IOL calculation team Tips for IOL power selection "Incorrect IOL power is the most common unanticipated outcome for any surgeon's practice." —Warren Hill, MD

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