Image-based Computational Hemodynamics for Endothelium Shear Stress in Human Choriocapillaris Using Volumetric Lattice Boltzmann Method

Disorders of the choroidal circulation are an etiologic element of age-related macular degeneration (AMD), affecting an estimated 2.5% of the world’s population, and causes blindness in millions of people. Endothelium shear stress (ESS) experienced by choroidal endothelial cells in health or disease has been suspected of contributing to physiology and pathophysiology of AMD, but it has never been studied in a anatomically realistic manner. Consequently, the biologic and pathologic effects of choroidal ESS are not known owing to the lack of appropriate research means. We present a unique and powerful computational platform, called InVascular, that enables quantification of ESS, in three-dimensional human choroidal vasculature networks derived from human cadaver eyes using kinetic-based lattice Boltzmann method. The choroidal vasclarture is reconstructed from high-resolution confocal microscopy staining of an human donor eyes. The anatomic segmentation of the inner choroidal vasculature, together with the pressure conditions at the arterioles and venules, is fed into InVascular to quantify the choridal hemodynamics. GPU-accelerated InVascular is highly computational efficient, enabling the study a large number of samples. Validation of InVascular against a state-of-the-art analytical model that uses an idealized geometry for choroicapillaries achieved excellent agreement in qualitative and quantitative metrics of blood flow. InVascular is expected to unveil changes in the distribution of ESS in heatlhy and diseased eyes. Insights gleaned from these studies could stimulate development of new prognostic analyses, such as ‘hemodynamic risk assessments’ to identify regions of the eye that are disease susceptible, or to stratify patients for enrollment in clinical trials.