Three-Dimensional Study Of Aqueous Humor Dynamics In Human Eye Based On OCT Images Modeling And Lattice Boltzmann Method

Aqueous humor plays a key role in maintaining the normal physiological activity of the human eyes,and studying the behavior and patterns of aqueous humor dynamics in the human eyes is of great relevance to understanding the pathogenesis of ocular diseases and improving treatment outcomes.However,existing numerical studies have mainly used ideal geometric models based on anatomical data,which do not reflect the influence of individual geometric features on aqueous humor dynamics in real human eyes tissue.In addition,traditional numerical methods have difficulties in dealing with complex boundaries and low computational efficiency,making it difficult to conduct in-depth studies of aqueous humor dynamics in the face of complex intraocular anatomy and aqueous humor patterns,the coexistence of multiple physical processes and large computational volumes.Optical Coherence Tomography(OCT)based images of the anterior segment of the eyes accurately reflect the individual geometric features of the tissue,which provides the basis for personalized geometric modelling.The Lattice Boltzmann Mothed(LBM)method,with its algorithmic simplicity,ease of handling complex boundaries and natural parallelism,has become an important method for the in-depth study of complex flow motion problems.Therefore,the organic combination of OCT and LBM will provide a new means to study in depth the aqueous humor of the real personalized human eyes.This paper investigates geometric modelling based on OCT images of the anterior segment of the eyes and numerical modelling of the LBM,and uses the developed model to simulate and analyze aqueous humor problems in real personalized human eyes.The main work is as follows:(1)A realistic geometric model of the anterior segment based on OCT images was constructed.Firstly,the original OCT images were pre-processed using image processing techniques to extract the geometric information of each tissue contour of the anterior segment,and then combined with the relevant anatomical structure data to build a 2D geometric model of the anterior segment.On the basis of this,the interpolated contour images were constructed by image alignment and interpolation algorithms to complete the three-dimensional structure information of the 3D model,and the coordinate conversion and gap filling algorithms were combined to generate a 3D mesh suitable for LBM simulation.The reconstruction of the 3D geometric model of the frontal segment is thus completed.(2)A 3D LBM-based numerical model of the aqueous humor dynamics of the human eyes was constructed.Two independent LB evolution equations are used to solve the velocity field composed of the aqueous humor flow and the temperature field formed by the temperature difference of human eyes tissues,and the coupling of velocity and temperature fields is achieved by Boussinesq approximation.In addition,to address the huge computational volume caused by differences in the scale of intraocular tissue,the model was accelerated by introducing Graphics Processing Unit(GPU)technology to design parallel algorithms.The performance test results show that the GPU parallel algorithm has about 1003 times higher computational performance compared to the CPU serial algorithm.(3)Using the validated model,the aqueous humor dynamics of the real personalized human eyes was investigated numerically.Firstly,in simulations of the asymmetric anterior chamber structure,it was found that asymmetric vortices formed as the aqueous humor entered the anterior chamber,causing it to flow more into larger areas of the cavity,potentially leading to uneven nutrient transport within the eyes;secondly,we investigated the effect of corneal depression on aqueous humor dynamics,and showed that corneal depression caused the aqueous humor to flow less rapidly in the anterior chamber;again,in exploring the effect of anterior chamber angle In exploring the effect of changes in size on atrial aqueous dynamics,we found that new vortices appeared above the lens,and that this new flow pattern had the potential to increase the risk of lens pigment accumulation;finally,we performed simulations of the pupillary ectasia situation and observed a more complex atrial aqueous flow pattern,with the number of vortices in the anterior chamber decreasing as the atrial angle increased and showing an asymmetric distribution.