PURPOSE To determine surgical parameters for arcuate keratotomy by simulating the intervention with a patient-specific model. SETTING University Eye Clinic Salzburg, Paracelsus Medical University, Austria, and Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland. DESIGN Computational modeling study. METHODS A new approach to plan arcuate keratotomy based on personalized finite element simulations was developed. Using this numeric tool, an optimization algorithm was implemented to determine the incision parameters that best met the surgeon's requirements while preserving the orientation of the astigmatism. Virtual surgeries were performed on patients to compare the performance of the simulation-based approach with results based on the Lindstrom and Donnenfeld nomograms and with intrastromal interventions. RESULTS Retrospective data on 28 patients showed that personalized simulation reproduced the surgically induced change in astigmatism (Pearson correlation = 0.8). Patient-specific simulation was used to examine strategies for arcuate interventions on 621 corneal topographies. The Lindstrom nomogram resulted in low postoperative astigmatism (mean 0.03 diopter [D] ± 0.3 [SD]) but frequent overcorrections (20%). The Donnenfeld nomogram and intrastromal incisions resulted in a small amount of overcorrection (1.5%) but a wider spread in astigmatism (mean 0.63 ± 0.35 D and 0.48 ± 0.50 D, respectively). In contrast, the new numeric parameter optimization approach led to postoperative astigmatism values (mean 0.40 ± 0.08 D, 0.20 ± 0.08 D, and 0.04 ± 0.13 D) that closely matched the target astigmatism (0.40 D, 0.20 D, and 0.00 D), respectively, while keeping the number of overcorrections low (<1.5%). CONCLUSION Using numeric modeling to optimize surgical parameters for arcuate keratotomy led to more reliable postoperative astigmatism, limiting the risk for overcorrection.

中文翻译：

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基于患者特定模型的手术参数优化：在弓形角膜切开术中的应用。

目的通过模拟针对特定患者的模型来确定弓形角膜切开术的手术参数。地点萨尔茨堡大学眼科诊所，奥地利Paracelsus医科大学以及瑞士伯尔尼大学外科技术和生物力学研究所。设计计算建模研究。方法开发了一种基于个性化有限元模拟的弓形角膜切开术的新方法。使用此数字工具，实施了一种优化算法，以确定最能满足外科医生要求的切口参数，同时保留了散光的方向。对患者进行了虚拟手术，以比较基于模拟的方法与基于Lindstrom和Donnenfeld诺模图的结果以及基质内干预的效果。结果28例患者的回顾性数据显示，个性化模拟再现了手术引起的散光变化（Pearson相关系数= 0.8）。使用针对特定患者的模拟来检查对621个角膜地形图进行弧形干预的策略。Lindstrom列线图导致较低的术后散光（平均0.03屈光度[D]±0.3 [SD]），但经常过度矫正（20％）。Donnenfeld列线图和基质内切口导致少量的过度矫正（1.5％），但散光散布范围更广（分别为0.63±0.35 D和0.48±0.50 D）。相反，新的数值参数优化方法导致术后散光值（分别为0.40±0.08 D，0.20±0.08 D和0.04±0.13 D）与目标散光（0.40 D，0.20 D和0.00 D）非常匹配，分别，同时保持较低的过校正次数（<1.5％）。结论使用数值模型优化弓形角膜切开术的手术参数可导致更可靠的术后散光，从而限制了过度矫正的风险。