Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
J Cataract Refract Surg. 2019 Aug;45(8):1084-1091. doi: 10.1016/j.jcrs.2019.02.022.
To determine surgical parameters for arcuate keratotomy by simulating the intervention with a patient-specific model.
University Eye Clinic Salzburg, Paracelsus Medical University, Austria, and Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
Computational modeling study.
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.
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%).
Using numeric modeling to optimize surgical parameters for arcuate keratotomy led to more reliable postoperative astigmatism, limiting the risk for overcorrection.
通过模拟患者特定模型，确定弧形角膜切开术的手术参数。
奥地利萨尔茨堡大学眼科诊所和伯尔尼大学外科技术和生物力学研究所Paracelsus 医科大学。
计算模型研究。
开发了一种基于个性化有限元模拟的弧形角膜切开术新方法。使用此数字工具，实现了优化算法，以确定在保留散光方向的同时，最能满足外科医生要求的切口参数。对患者进行了虚拟手术，比较了基于模拟的方法与基于 Lindstrom 和 Donnenfeld 图表以及间质内干预的结果。
对 28 名患者的回顾性数据表明，个性化模拟复制了手术引起的散光变化（Pearson 相关系数为 0.8）。患者特定的模拟用于检查 621 个角膜地形图的弧形干预策略。Lindstrom 图表导致术后散光低（平均 0.03 屈光度[D]±0.3 [SD]），但频繁出现过矫（20%）。Donnenfeld 图表和间质切口导致少量过矫（1.5%），但散光范围更广（分别为平均 0.63±0.35 D 和 0.48±0.50 D）。相比之下，新的数值参数优化方法导致术后散光值（平均 0.40±0.08 D，0.20±0.08 D 和 0.04±0.13 D）分别与目标散光（0.40 D，0.20 D 和 0.00 D）非常匹配，同时保持过矫的数量较低（<1.5%）。
使用数值建模来优化弧形角膜切开术的手术参数可导致更可靠的术后散光，从而降低过矫的风险。
