EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/1422338
44 | EYEWORLD | DECEMBER 2021 ATARACT C by Liz Hillman Editorial Co-Director About the physicians Bryan S. Lee, MD, JD Altos Eye Physicians Los Altos, California Kevin M. Miller, MD Kolokotrones Chair in Ophthalmology David Geffen School of Medicine University of California, Los Angeles Los Angeles, California Carlos Martinez, MD Eye Physicians of Long Beach Long Beach, California and could, in some cases, make outcomes worse if its recommendations are followed? That's the dilemma, Dr. Miller said. Carlos Martinez, MD, said he's learned which cases to favor ORA vs. preop data. Cases he'll favor include post-refractive surgery cases, astigmatism management cases, and those with irregular corneas. "I use ORA in advanced technology lens cases and find it incredibly useful, especially in post-refractive cases and astigmatism manage- ment cases. My post-RK and post-LASIK mea- surements are right on the dot. They both have a standard deviation of error as a regular lens thanks to ORA," he said. When ORA is not in agreement with preop measurements, Dr. Martinez said he'll go back to his data and look for outliers. "Most of the time, I can see a cluster. Occasionally, IOLMaster [Carl Zeiss Meditec] is off as to the amount of the magnitude of astigmatism or even power. In addition, some- times technicians forget to look at the quality of keratometry readings on the IOLMaster," he said. "I compare my IOLMaster measurements to my ORA measurements. If they agree, I don't do anything else. I have a higher level of confidence that I have the right power, axis, and alignment. ORA helps me decide what numbers are within a cluster and which numbers are outliers. When there is no agreement, I use my ORA measurements. In post-refractive patients, I mostly use ORA." Dr. Miller gave two examples where ORA recently helped improve his outcomes. The first was a patient who had post-myopic LASIK, with a correction of about –7 D or –8 D. He said he's comfortable with his post-LASIK IOL power cal- culations, so he was confident in the lens power he had selected. When he used ORA during the case, however, it was telling him to go 2 D away from his original plan. He said he repeated the measurements multiple times and kept getting the same ORA result. "I didn't want to ignore the ORA com- pletely, so … I ended up going a half a diopter toward what ORA told me to do. On postop day 1, the patient was 20/20 –1 or –2. … If I had followed my original plan, I would have been off," he said. Intraoperative refractive guidance systems I ntraoperative refractive guidance systems is a term coined by Kevin M. Miller, MD, de- scribing the technology offered to patients as an additional, out-of-pocket benefit for their cataract surgeries. Dr. Miller said within this class of technol- ogies are systems that give surgeons guidance on refractive issues during the case, including spherical power, cylinder power and alignment, and more. He said that using the term "intraop- erative refractive guidance" is a communication aid with patients. "Patients don't need to know which device or combination of devices we're using. They just want to know we're using the latest technology to give them the best chance at a good refrac- tive result," he said. Intraoperative aberrometry ORA (Alcon) is currently the only intraoperative aberrometry unit on the market in the U.S. It is used after a cataract is removed to confirm (or in some cases alter) IOL selection and placement. "Roughly two-thirds of the time, ORA is going to tell you the lens you should be putting in is the lens you planned on putting in. So two- thirds of the time, it provides no benefit other than a check that we have alignment of the stars," Dr. Miller said. "Then there is the other third of the time when it tells you to do some- thing you weren't planning to do—go up or down on the power of the sphere, the cylinder, or both." How does a surgeon decide to change course based on what ORA is telling them? Dr. Miller said there are three scenarios: 1) Ignore ORA and do what you were originally planning. 2) Do something between what you were plan- ning and what ORA tells you to do. 3) Change course and go with ORA's recommendation. Dr. Miller said you have to do your own data analysis, but based on his outcomes, he's learned that his outcomes are about 7% better by one metric than if he didn't use ORA. This means that he's doing well without ORA but that it does make him a little better, Dr. Miller said. Is it worth the expense and extra time, knowing that it won't make every case better