CATARACT EWAP SEPTEMBER 2023 15 D. 3 However, only 67.2% and 94.8% of eyes were within ±0.50 D and ±1.0 D from the target refraction, respectively,” Dr. Fram said. “Haigis reviewed 187 eyes and found that using the Haigis-L formula, the percentages of correct 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 keratometry. 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 literature 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 dominant 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 improve outcomes, especially in the case of prior RK. 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 understood by everyone involved that these eyes do change over time.” Dr. Fram said if ablation is being considered, 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 correction for some activities such as driving at night or reading very small print. If there is a hyperopic outcome, the surgeon should be prepared to perform an IOL exchange,” she said. EWAP References 1. Alsetri H, et al. Diffractive optic intraocular lens exchange: indications and outcomes. J Cataract Refract Surg. 2022;48:673–678. 2. Fram NR, et al. Comparison of intraoperative aberrometry, OCT-based IOL formula, Haigis-L, and Masket formulae for IOL power calculation after laser vision correction. Ophthalmology. 2015;122:1096 –1101. 3. Abulafia A, et al. Accuracy of the Barrett True-K formula for intraocular lens power prediction after laser in situ keratomileusis or photorefractive keratectomy for myopia. J Cataract Refract Surg. 2016;42:363–369. 4. Haigis W. Intraocular lens calculation after refractive surgery for myopia: Haigis - L formula. J Cataract Refract Surg. 2008;34:1658 –1663. 5. Lawless M, et al. Total keratometry in intraocular lens power calculations in eyes with previous laser refractive surgery. Clin Exp Ophthalmol. 2020;48:749 –756. 6. Yeo TK, et al. Accuracy of intraocular lens formulas using total keratometry in eyes with previous myopic laser refractive surgery. Eye (Lond). 2021;35:1705 – 1711. 7. Wang L, et al. Evaluation of total keratometry and its accuracy for intraocular lens power calculation in eyes after corneal refractive surgery. J Cataract Refract Surg. 2019;45:1416 –1421. 8. Lanza M, et al. Accuracy of formulas for intraocular lens power calculation after myopic refractive surgery. J Refract Surg. 2022;38:443 – 449. 9. Refractive prediction accuracy using intraoperative aberrometry versus Barrett True-K formula in post-corneal refractive surgery eyes. Presentation at the 2021 American Academy of Ophthalmology Meeting, New Orleans, Louisiana. Editors’ note: Dr. Fram practices at Advanced Vision Care, Los Angeles, California, and has interests with Johnson & Johnson Vision, Alcon, Bausch + Lomb, RxSight, and Carl Zeiss Meditec. Dr. Hill practices at East Valley Ophthalmology, Mesa, Arizona, and declared no relevant financial interests. Making...Post-refractive - from page 13
RkJQdWJsaXNoZXIy Njk2NTg0