Keywords
Abstract
This work aims at investigating the interactions between the flow of fluids in the brain and eyes, and their potential implications in the development of visual impairment and intracranial pressure (VIIP) syndrome in astronauts. We propose a reduced (0-D) mathematical model of fluid circulation in the eyes and brain, which is embedded into a simplified whole-body circulation model. This model allows us to predict fluid redistribution in the upper body vasculature as well as variation of the intracranial (ICP) and intraocular (IOP) pressures. The model results suggest that, by taking into account some eff ects of microgravity, it is possible to observe, on one hand, an increase in IOP, and on the other, a decrease in blood flow circulation in the choroid and ciliary body. These findings provide clues for the role that vascular components may play in VIIP pathogenesis, for which astronauts could be screened on Earth and in-flight.
References
Sigal IA, Flanagan JG, Tertinegg I, Ethier CR. finite element modeling in optic nerve. Invest Ophthalmol Vis Sci. 2004;45(12):4378–4387.
Sigal IA, Hongli Y, Roberts MD, Burgoyne CF, Downs CJ. IOP-induced lamina cribrosa displacement and scleral canal expansion: an analysis of factor interactions using parameterized eye-specific
models. Invest Ophthalmol Vis Sci. 2011;52(3):1896–1907.
Sigal IA, Grimm JL, Jan NJ, Reid K, Minckler DS, Brown DJ. Eye-specific IOP-induced displacements and deformations of human lamina cribrosa. Invest Ophthalmol Vis Sci. 2011;55(1):1–15.
Causin P, Guidoboni G, Harris A, Prada D, Sacco R, Terragni S. A poroelastic model for the perfusion of the lamina cribrosa in the optic nerve head. Math Biosci. 2014;(257):33–41.
Guidoboni G, Harris A, Carichino L, Arieli Y, Siesky BA. Effect of intraocular pressure on the hemodynamics of the central retinal artery: a mathematical model. Math Biosci Eng. 2014;(11):523–546.
Biot MA. General theory of of three-dimensional consolidation. J Appl Phys. 1941;(12):155–164.
Biot MA. Theory of finite deformations of porous solids. Ind Univ Math J. 1972;21:597–620.
Larchè F, Cahn JW. Linear theory of thermomechanical equilibrium solids under stress. Acta. Metall. 1973;21:1051–1063.
Larchè F, Cahn JW. The interactions of composition and stress in crystalline solids. J Res Natl Bur Stand. 1984;89:467–500.
Honga W, Zhaoa X, Zhoua J, Suo Z. A theory of coupled diusion and large deformation in polymeric gels. J Mechan Phys Solids. 2008;56:1779–1793.
Eshelby JD. Elastic energy momentum tensor. J Elasticity. 1975;5:331–335.