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lei lin, Pingjun Chang, Jialu Xie, Fan Lu, Yun-e Zhao; Sustained accuracy improvement in intraocular lens power calculation with the application of quality control circle. Invest. Ophthalmol. Vis. Sci. 2017;58(8):1148.
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© ARVO (1962-2015); The Authors (2016-present)
Non-optimized process of intraocular lens (IOL) power calculation may lead to inaccurate refractive outcome. Quality control circle (QCC), a process management tool, has never been used in the field of ophthalmology. This retrospective clinical study was performed to optimize the IOL power calculation process utilizing QCC and test its efficacy in improving the accuracy of IOL power calculation.
The retrospective data of 107 patients (155 eyes) who had cataract surgery between November 2013 and September 2014 were reviewed to analyze the reasons related with the inaccurate IOL power calculation depending on QCC. Based on these reasons, three main strategies were formulated to optimize the process of IOL power calculation as follows: (1) the biological measurement protocol was normalized using the average of repeated measurement and/or checking the results by different operators; (2) the IOL constant was optimized refer to the User Group for Laser Interference Biometry; (3) the ray-tracing method PhacoOptics was applied in patients with long axial length (AL≥ 26mm). Then the optimized process was applied to another retrospective data of 92 patients (131 eyes) from March 2015 to January 2016 to verify the efficacy of QCC in improving the accuracy of IOL power calculation.
In patients with normal AL (22mm ≤ AL＜26mm), the percentage of eyes with achieved refractive outcomes within 0.5 D significantly increased from 58.2% to 79.7% calculated by the Haigis formula and 58.2% to 86.1% by SRK/T formula after using the optimized process (Figure. 1). Although there were no statistically significant differences in patients with long axial length by the two formulas (p=0.726 and 0.866), the accuracy reached as high as 75% with the application of PhacoOptics, which was significantly higher than that using the other two formulas (p＜0.001).
This study demonstrated that QCC optimized and standardized the process of IOL power calculation, thus improved the accuracy of IOL power calculation in patients underwent cataract surgery. QCC may be a promising tool in clinical evaluation and management of refractive surgery.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
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