A personalized simulation framework for optimizing orthokeratology lens parameters based on 3D corneal modeling and biomechanical analysis

Q Chen, Enxu Peng, Gaiping Zhao, Ping Ye, Zhaohua Chang

The aim of this study was to develop a patient-specific finite element model (FEM) to elucidate the biomechanical mechanisms governing orthokeratology (OK) lens design in real ocular conditions. Based on clinical corneal topography data, a patient-specific FEM was developed to incorporate asymmetric anatomical features. This model integrated an improved Iterative Closest Point (ICP) algorithm and a non-uniform squeeze-film pressure field. Simulation results were then compared with clinical measurements across multiple dimensions to evaluate predictive accuracy. The simulation framework demonstrated high predictive fidelity, The average Structure Similarity Index <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mrow> <mml:mi>S</mml:mi> <mml:mi>S</mml:mi> <mml:mi>I</mml:mi> <mml:mi>M</mml:mi> </mml:mrow> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> was 0.73, and the average Pearson correlation coefficient <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m2"> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mrow> <mml:mi>P</mml:mi> <mml:mi>C</mml:mi> <mml:mi>C</mml:mi> </mml:mrow> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> reached 0.85. Treatment zone metrics: ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m3"> <mml:mrow> <mml:mi>T</mml:mi> <mml:msub> <mml:mrow> <mml:mi>Z</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">radius</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> accuracy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m4"> <mml:mrow> <mml:mo>=</mml:mo> <mml:mn>93.7</mml:mn> <mml:mi>%</mml:mi> </mml:mrow> </mml:math> , Mean Absolute Error, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m5"> <mml:mrow> <mml:mi>M</mml:mi> <mml:mi>A</mml:mi> <mml:mi>E</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.14</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>m</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:math> ); ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m6"> <mml:mrow> <mml:mi>T</mml:mi> <mml:msub> <mml:mrow> <mml:mi>Z</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>S</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> accuracy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m7"> <mml:mrow> <mml:mo>=</mml:mo> <mml:mn>88.8</mml:mn> <mml:mi>%</mml:mi> </mml:mrow> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m8"> <mml:mrow> <mml:mi>M</mml:mi> <mml:mi>A</mml:mi> <mml:mi>E</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1.73</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>m</mml:mi> <mml:msup> <mml:mrow> <mml:mi>m</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> ). The maximum dioptric change ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m9"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>D</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">max</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> accuracy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m10"> <mml:mrow> <mml:mo>=</mml:mo> <mml:mn>79.0</mml:mn> <mml:mi>%</mml:mi> </mml:mrow> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m11"> <mml:mrow> <mml:mi>M</mml:mi> <mml:mi>A</mml:mi> <mml:mi>E</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.57</mml:mn> <mml:mi>D</mml:mi> </mml:mrow> </mml:math> ) Statistical analysis was performed to evaluate the effects of two Back Optic Zone Diameters (BOZD) and two Targeted Dioptric Reductions (TDR) on biomechanical outcomes. A personalized FEM for the biomechanical analysis of OK was successfully developed, providing biomechanical theoretical support for the optimization of customized lens parameters.