Thanadet Chuangsuwanich1, K Erik Birgersson2, Alexandre Thiery3, Sri Gowtham Thakku4, Hwa Liang Leo1, Michaël J A Girard5. 1. Department of Biomedical Engineering, National University of Singapore, Singapore. 2. Department of Chemical Engineering, National University of Singapore, Singapore. 3. Department of Statistics, National University of Singapore, Singapore. 4. Singapore Eye Research Institute, Singapore National Eye Centre, Singapore. 5. Department of Biomedical Engineering, National University of Singapore, Singapore 4Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Abstract
PURPOSE: To identify and rank the lamina cribrosa (LC) morphologic factors that influence LC microcapillary hemodynamics and oxygen concentrations using computational fluid dynamics (CFD). METHODS: We generated 12,000 'artificial' LC microcapillary networks and predicted blood flow velocities and oxygen concentrations within the microcapillaries using CFD. Across models, we varied the average pore size of the LC (5500 ± 2400 μm2), the microcapillary arrangement (radial, isotropic, or circumferential), the LC diameter (1.9 ± 0.3 mm), the inferior-superior curvature (340 ± 116 m-1), and the nasal-temporal curvature (-78 ± 130 m-1). We assumed that blood flow originated from the Circle of Zinn-Haller, fed the LC uniformly at its periphery, and was drained into the central retinal vein. Arterial (50 ± 6 mm Hg) and venous (17.7 ± 6 mm Hg) pressures were applied as boundary conditions and were also varied within our simulations. Finally, we performed linear regression analysis to rank the influence of each factor on LC hemodynamics and oxygen concentrations. RESULTS: The factors influencing LC hemodynamics and oxygen concentrations the most were: LC diameter, arterial pressure, and venous pressure, and to a lesser extent: the microcapillary arrangement (anisotropy) and nasal-temporal curvature. Lamina cribrosa pore size and superior-inferior curvature had almost no impact. Specifically, we found that LCs with a smaller diameter, a radial arrangement of the microcapillaries, an elevated arterial pressure and a decreased venous pressure had higher oxygen concentrations across their networks. CONCLUSION: This study described LC hemodynamics using a computational modeling approach. Our study may provide clinically relevant information for the understanding of ischemia-induced neuronal cell death in optic neuropathies.
PURPOSE: To identify and rank the lamina cribrosa (LC) morphologic factors that influence LC microcapillary hemodynamics and oxygen concentrations using computational fluid dynamics (CFD). METHODS: We generated 12,000 'artificial' LC microcapillary networks and predicted blood flow velocities and oxygen concentrations within the microcapillaries using CFD. Across models, we varied the average pore size of the LC (5500 ± 2400 μm2), the microcapillary arrangement (radial, isotropic, or circumferential), the LC diameter (1.9 ± 0.3 mm), the inferior-superior curvature (340 ± 116 m-1), and the nasal-temporal curvature (-78 ± 130 m-1). We assumed that blood flow originated from the Circle of Zinn-Haller, fed the LC uniformly at its periphery, and was drained into the central retinal vein. Arterial (50 ± 6 mm Hg) and venous (17.7 ± 6 mm Hg) pressures were applied as boundary conditions and were also varied within our simulations. Finally, we performed linear regression analysis to rank the influence of each factor on LC hemodynamics and oxygen concentrations. RESULTS: The factors influencing LC hemodynamics and oxygen concentrations the most were: LC diameter, arterial pressure, and venous pressure, and to a lesser extent: the microcapillary arrangement (anisotropy) and nasal-temporal curvature. Lamina cribrosa pore size and superior-inferior curvature had almost no impact. Specifically, we found that LCs with a smaller diameter, a radial arrangement of the microcapillaries, an elevated arterial pressure and a decreased venous pressure had higher oxygen concentrations across their networks. CONCLUSION: This study described LC hemodynamics using a computational modeling approach. Our study may provide clinically relevant information for the understanding of ischemia-induced neuronal cell death in optic neuropathies.
Authors: Susannah Waxman; Bryn L Brazile; Bin Yang; Po-Yi Lee; Yi Hua; Alexandra L Gogola; Po Lam; Andrew P Voorhees; Joseph F Rizzo; Tatjana C Jakobs; Ian A Sigal Journal: Exp Eye Res Date: 2021-12-29 Impact factor: 3.467
Authors: Yi Hua; Andrew P Voorhees; Ning-Jiun Jan; Bingrui Wang; Susannah Waxman; Joel S Schuman; Ian A Sigal Journal: Exp Eye Res Date: 2020-08-14 Impact factor: 3.467
Authors: Alon Harris; Giovanna Guidoboni; Brent Siesky; Sunu Mathew; Alice C Verticchio Vercellin; Lucas Rowe; Julia Arciero Journal: Prog Retin Eye Res Date: 2020-01-24 Impact factor: 21.198