Eyeworld

42 | EYEWORLD | JULY 2023 ATARACT C Contact Fram: drfram@avceye.com Hill: hill@doctor-hill.com Postop What if an enhancement is needed postop? Dr. Hill said this is rare, but if there is a significant refractive miss, IOL exchange is his preference. He said that the LAL "dramatically reduces this possibility," but he noted, "it must be under- stood by everyone involved that these eyes do change over time." Dr. Fram said if ablation is being consid- ered, it's important to see if the cornea can withstand another such a treatment. "Typically, even the monovision patients are consented that they may need spectacle correc- tion for some activities such as driving at night or reading very small print. If there is a hyper- opic outcome, the surgeon should be prepared to perform an IOL exchange," she said. refraction predictions were within ±1.00 and ±0.50 D in 84.0%, and 61.0%, respectively. 4 "Most recently, Lawless et al. reported that using the Barrett True-K TK resulted in 75% within ±0.5 D versus 45% within ±0.5 D using the ASCRS calculator and standard keratom- etry. 5 Similarly, Yeo et al. found that EVO TK, Barrett True-K TK, and Haigis TK achieved 68%–64% within ±0.50 D. 6 Lastly, Wang et al. found that the performance of the combination of Haigis and TK in refractive prediction was comparable with Haigis-L and Barrett True-K in eyes with previous corneal refractive surgery," 7 Dr. Fram said. Dr. Fram continued that more recent litera- ture has shown the Haigis-L, 8 Barrett True-K TK formula, 5 ORA System (Alcon) intraoperative aberrometry nomograms, 9 and ASCRS calculator mean can achieve emmetropia up to 74%–76%. Intraoperative stage When in surgery, Dr. Fram said she'll look at the ASCRS calculator average, Barrett True-K TK, using IOLMaster 700 (Carl Zeiss Meditec), and will use intraoperative aberrometry. "Of note, if there is anterior corneal astigmatism measured, I will look at the total K on the IOLMaster 700 to confirm magnitude and axis, what the patient was wearing in their glasses and axis, as well as use intraoperative aberrometry to look at the total aphakic refraction rather than simply the anterior measured astigmatism," she said. She added that the Barrett True-K Toric is valuable if not using the LAL technology. If she's using an LAL, she said she'll pick the first plus on the Barrett True-K TK for the domi- nant eye and –0.75 D for the non-dominant eye. "I will add in the myopic correction to allow for an 'EDOF effect' by changing the spherical aberration of the adjusted IOL," she said. Dr. Hill said his surgery is not different for patients with prior LASIK, PRK, or ALK. If the patient had RK and the incisions are too closely spaced, he will use a scleral tunnel. Dr. Hill said that intraoperative aberrometry would not im- prove outcomes, especially in the case of prior RK. continued from page 41 Relevant disclosures Fram: Johnson & Johnson Vision, Alcon, Bausch + Lomb, RxSight, Carl Zeiss Meditec Hill: None What's one thing you think surgeons should be doing with post-refractive patients who are cataract surgery candidates that many aren't doing already? Dr. Fram: Understand the advancements in formulae, try to not leave the consenting process to a surgical counselor alone, and be prepared for an IOL exchange (particu- larly if using diffractive technology and/or if you do not have access to the LAL). Dr. Hill: Take all the time necessary to ex- plain the limitations involved in the process. Essential items are: 1) This is not routine surgery for which all options are possible; 2) the calculation accuracy is less than for reg- ular cataract surgery; and 3) the reduced contrast from elevated higher order aber- rations will persist, especially at larger pupil sizes. Use image simulation to demonstrate what the postoperative vision will be.

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