Research On 3D Corneal Parametric Modeling Based On Corneal Topographic Map

Objective: The cornea is the main component of the refractive system of the eyeball,which greatly affects the overall optical performance and visual quality of the eyeball.And it is vulnerable to trauma because it is located at the front of the eyeball;in eyeball diseases,corneal diseases such as keratoconus have a high incidence.With the rapid development of computer-aided design(CAD)in the field of medicine,the study of corneal morphology has become a hot spot at home and abroad,especially the establishment of three-dimensional cornea.Based on the data of normal human corneal topography,this study uses CREO software to build a parameterized three-dimensional forward model of the cornea,and establishes a finite element model to establish a more powerful foundation for corneal analysis.Methods:1.A healthy adult woman was selected as the simulation object,and corneal data were collected by corneal topography and three-dimensional coherent optical tomography(3D-OCT).2.Based on the above data and using Creo Parametric 3.0 software,a parameterized three-dimensional geometric partial model within the range of diameter 7 mm is established.3.Adjust the position and angle of the partial model in Mimics 15.0 software.4.The partial model is United,repaired and smoothed by Geomagic Studio 12.0 software.5.In the 3-matic 7.0 module of Mimics 15.0,each partial model is stitched into a whole and adjusted automatically to construct a complex three-dimensional geometric corneal model.6.In the 3-matic 7.0 module of Mimics 15.0 and ANSYS Workbench 17.0,the finite element model of cornea is constructed according to the geometric model,and the pressure is applied in the structural mechanics analysis module to simulate intraocular pressure.Results:1.The three-dimensional geometric partial model of the inner and outer surface of the corneal diameter 7 mm range was successfully established,including 3 parts within the diameter 3 mm range,4 parts within the diameter 3-5 mm range and 4 parts within the diameter 5-7 mm range.2.The position and angle of the partial model are adjusted properly in the Mimics 15.0 software,and the 11 partial models are successfully combined,repaired and smoothed in the Geomagic Studio 12.0 software.3.In the 3-matic 7.0 module of Mimics 15.0,the partial models were stitched into a whole and adjusted automatically,and the three-dimensional geometric corneal model was successfully constructed with a total number of 30892 units.4.The finite element model of the above complex three-dimensional geometric corneal model was generated in Mimics 15.0 and ANSYS Workbench 17.0.The total number of points is 46610 and the total number of units is 12269.5.The applied intraocular pressure is simulated in the structural mechanics analysis module of ANSYS Workbench 17.0,and the model is analyzed after solving the problem.Conclusions:1.Based on the data of normal human corneal topography,a three-dimensional geometric model of human cornea with high similarity is reconstructed by using related software.2.The partial model can be highly optimized and integrated into a visual three-dimensional geometric model by using Mimics 15.0 and Geomagic Studio 12.0 software.3.The three-dimensional geometric model verified by ANSYS Workbench 17.0 software can be used for biomechanical analysis.