EyeWorld India June 2020 Issue

EWAP JUNE 2020 13 FEATURE W ith increasing precision in IOL calculation formulas, surgeons may wonder if there is still a role for intraoperative aberrometry. Those currently using the technology say it is helpful, especially in certain patients. “I think there’s a nice role vœÀ >LiÀÀœ“iÌÀÞ Ìœ Vœ˜wÀ“ œÀ modify IOL power. It still has a place,” said Douglas Koch, MD. The key is knowing when to use it. Best uses of aberrometry There are several ideal scenarios for intraoperative aberrometry. One of those is when trying ̜ >V…ˆiÛi > ëiVˆwV ÀivÀ>V̈Ûi target. “It’s ideal for toric and multifocal lenses and in patients with prior refractive surgery,” said John Berdahl, MD. Among toric IOL patients, many surgeons will use intraoperative aberrometry for IOL orientation and alignment. “They think it does the best job of aligning the posterior and anterior cornea,” said Dr. Koch, who previously introduced the importance of posterior cornea measurements. Intraoperative aberrometry is useful in post-refractive surgery eyes because it can be harder to achieve accuracy with this patient group. However, it’s important to consider the type of surgery a patient had. “Although it can be helpful in radial keratotomy patients, ̅iÞ V>˜…>Ûi È}˜ˆwV>˜Ì yÕVÌÕ>̈œ˜Ã]» À° iÀ`>… Ã>ˆ`° “It’s not necessarily unhelpful, but that needs to be taken into account with the full picture.” Another use for intraoperative >LiÀÀœ“iÌÀÞ ˆÃ ̜ Vœ˜wÀ“ ܅>Ì you may already have in mind for IOL power. “Using it decreases errors from inadvertently implanting the wrong IOL due to clerical errors,” said Bonnie Henderson, MD. Dr. Koch shared the example of a patient of his who needed an IOL exchange and had a toric IOL. Using the website AstigmatismFix.com, Dr. Koch didn’t get the IOL choice that he expected. “At the time of surgery, I used intraoperative aberrometry, and it pointed me in the direction I thought it would logically go. We got a great result,” he said. He also shared a scenario in which wrong data were uploaded onto the website he usually uses for IOL calculations. However, with aberrometry, he was able to catch that and identify an appropriate IOL power. In addition to these common uses, Dr. Henderson has found several other reasons to choose intraoperative aberrometry, including with irregular corneal pathology (such as scarring) where measurements may not be accurate, cases of macular pathology or staphylomas, and eyes with long or short axial lengths. “In my practice, intraoperative aberrometry has replaced the use of immersion A-scan in many of these unusual eyes,” she said. Calculation changes Just how often does the use of aberrometry change the IOLs that surgeons might use? For Dr. Berdahl, it will change his choice of a toric lens about 30% of the time. In post- refractive cases, it changes his decision about 20–30% of the time. For standard eyes with no special needs or pathology, it only changes his choice about 5% of the time; these are not iÞià ̅>Ì ÌÞ«ˆV>Þ Li˜iwÌ vÀœ“ aberrometry, Dr. Berdahl added. For Dr. Koch, the use of aberrometry changes his choice in post-LASIK eyes about 25% of the time. However, he pointed out that he and his colleagues do a lot of research on preop measurements, so he has two biometers used before surgery. Additionally, they do many more preop calculations, beyond what other surgeons typically do. Considering the latest IOL formulas iëˆÌi ̅iÃi «œÌi˜Ìˆ> Li˜iwÌà from using intraoperative aberrometry, there still is the question of its value when there are newer IOL power calculation formulas, such as the Hill- RBF and Barrett Universal II formulas, View from the ORA (Alcon) as seen in the right ocular of the surgical microscope. Source: Samuel Masket, MD Intraoperative aberrometry’s role in guiding IOL decisions AT A GLANCE • Intraoperative aberrometry can help guide a surgeon’s IOL choices. • This type of technology is valuable in eyes that have had refractive surgery or those receiving toric IOLs. • The use of newer IOL formulas may change or lessen the role of aberrometry. • Appropriate hydration and wÝ>̈œ˜ V>˜…i« ˆ“«ÀœÛi results. by Vanessa Caceres Contributing Writer Contact information Berdahl: john.berdahl@vancethompsonvision.com Henderson: bahenderson@eyeboston.com Koch: dkoch@bcm.edu This article originally appeared in the March 2020 issue of EyeWorld . It has DGGP UNKIJVN[ OQFKƂGF CPF CRRGCTU here with permission from the ASCRS Ophthalmic Services Corp.