EyeWorld Asia-Pacific June 2020 Issue

FEATURE 14 EWAP JUNE 2020 To help avoid these factors and to improve your aberrometry results, here are a few clinical pearls: 1. Protect the corneal epithelium. Start as soon as the patient is in the ASC and until the time of measurement, Dr. Koch advised. 2. Keep the cornea protected with OVD or with frequent irrigation. A cohesive OVD ŜՏ` Li ÕÃi` ̜ w ̅i iÞi rather than a dispersive OVD or a hybrid OVD with a high molecular weight, Dr. Henderson said. 3. Make sure the patient is NQQMKPI FKTGEVN[ CV VJG ƂZCVKQP light. Ask him or her to tell you when that light goes out. “That helps guarantee that they are looking in the correct direction,” Dr. Koch said. 4. Use the personalized outcomes to help guide decisions. À° iÀ`>… w˜`à ̅i numbers that are particular to his surgical outcomes more useful than global outcomes. “With time, you get a sense of when you should trust [the numbers] more and when you shouldn’t,” he said. EWAP Editors’ note: Dr. Berdahl practices at Vance Thompson Vision, Sioux Falls, South Dakota. Dr. Henderson is clinical professor, Tufts University School of Medicine, Boston, Massachusetts. Drs. Berdahl and Henderson declared relevant interests with Alcon. Dr. Koch is Professor and Allen, Mosbacher, and Law Chair in Ophthalmology, Baylor College of Medicine, Houston, Texas, and declared relevant interests with Alcon, Carl Zeiss Meditec, and Johnson & Johnson Vision. Michael Lawless, MD Clinical associate professor Vision Eye Institute 4/270 Victoria Ave., Chatswood, NSW, Australia Michael.lawless@vei.com.au ASIA-PACIFIC PERSPECTIVES T …ˆÃ ˆÃ >˜ ˆ˜ÌiÀiÃ̈˜} >À̈Vi LÞ iÝ«iÀÌà ˆ˜ ̅i wi`° ̅ˆ˜Ž ̅iˆÀ initial sentence is correct “with increasing precision in IOL calculation formulas, surgeons may wonder if there is still a role for intraoperative aberrometry.” I would also add that with the widespread use of digital alignment for toric IOLs, surgeons are even more likely to question the value of intraoperative aberrometry. This is particularly true since digital alignment systems add to the accuracy of ̅i w˜> ̜ÀˆV " «œÃˆÌˆœ˜] >˜` >Ãœ >`` ̜ ̅i ivwVˆi˜VÞ œv ÃÕÀ}iÀÞ] whereas intraoperative aberrometry tends to bring accuracy at the iÝ«i˜Ãi œv ivwVˆi˜VÞ° The authors state the key is “knowing when to use it” and they come up with a number of scenarios. I would suggest, though, that being given the incorrect IOL in theater is not really a reason to feel that intraoperative aberrometry should be your solution here. There should be better system checks in place so that this does not happen. The authors note nine things which can adversely alter the measurements, and they include the lid speculum, corneal edema, not wˆ˜} ̅i iÞi >««Àœ«Àˆ>ÌiÞ ܈̅̅i VœÀÀiVÌ "6 ] > `ÀÞ ÃÕÀv>Vi] «œœÀ patient focusing, etc. This is a big list, and I think surgeons intuitively think how can this be accurate when all these things have to be right in order for the system to perform at its best? It is really asking too much in the real world that all these things can be controlled in a way that >œÜà Õà ̜ Li Vœ˜w`i˜Ì >LœÕÌ ˆ˜ÌÀ>œ«iÀ>̈Ûi >LiÀÀœ“iÌÀÞ] >Ì…œÕ}… the underlying premise and theory behind it is good. The dilemma is also this: I have cases where I would consider intraoperative aberrometry. Sadly, where I really need it most, which is post radial keratotomy, it has not been shown to be reliable enough as the authors attest in this article. There are other cases, albeit rare, such as a very unusual post refractive or a very short eye, where it would be ˜ˆVi ̜ Vœ˜wÀ“ ̅>Ì Ì…i «œÜiÀ ˆÃ VœÀÀiVÌ œ˜ ̅i Ì>Li° /…i «ÀœLi“ ˆÃ that this is a system which requires routine and repetitive use in order to get the best from the technology, and if I am going to use it rarely, I will never develop a level of expertise which allows me to be truly Vœ˜w`i˜Ì ˆ˜ ̅i “i>ÃÕÀi“i˜Ìð iÀi ˆÃ ̅i «ÀœLi“\ v ÞœÕ ÕÃi ˆÌ œ˜ every patient, well and good, you would become very familiar with ܅>Ì ˆÃ >…ˆ}…µÕ>ˆÌÞ ÌiV…˜œœ}Þ >˜` «ÀœL>LÞ }iÌ Li˜iwÌ vÀœ“ ˆÌÆ LÕÌ for most surgeons where it would only be used rarely, it is hard to see ̅>Ì Ì…iÞ ÜœÕ`…>Ûi Vœ˜w`i˜Vi ˆ˜ ̅iˆÀ >LˆˆÌÞ Ìœ }iÌ Ì…i LiÃÌ vÀœ“ this technology. In my view, its place is limited, but I fully understand why occasional ÃÕÀ}iœ˜Ã `œ w˜` ˆÌ œv Û>Õi >˜` ÕÃi ˆÌ Ài}Տ>ÀÞ° Editors’ note: Dr. Lawless is a consultant for Alcon and Zeiss. known for their high level of accuracy. “As these formulas have improved, there’s less of a Li˜iwÌ Ìœ ˆ˜ÌÀ>œ«iÀ>̈Ûi aberrometry in standard cases, LÕÌ Ì…i Li˜iwÌ ˆÃ Ã̈ “i>˜ˆ˜}vՏ in toric lenses and post-refractive cases,” Dr. Berdahl said. “As good as these newer formulas are, intraoperative aberrometry is still better than an IOL formula alone,” Dr. Henderson said, adding that the change in IOL power made by many surgeons using intraoperative aberrometry has led to an improvement in their outcomes. Dr. Koch thinks the role of aberrometry will diminish as formulas continue to improve, but the end result is situation- and surgeon- ëiVˆwV° º Ì `i«i˜`à œ˜…œÜ many measurements a surgeon gets. If it’s just one biometer measurement, then [the results] from intraoperative aberrometry could be a lifesaver,” he said. 4GƂPKPI [QWT WUG HQT better results If you’re using aberrometry, keep in mind that there are a few factors that can adversely alter the readings. These include: • The lid speculum • Trauma to the epithelium • Corneal edema • œÌ wˆ˜} ̅i iÞi ܈̅̅i appropriate ophthalmic viscosurgical device (OVD) • A dry corneal surface • Poor patient focusing • A low or high IOP • The wrong input of preop data • Scars