Experimental and numerical response of a passive glaucoma drainage device

Abstract

Glaucoma is the optic nerve damage often associated with an increased intraocular pressure that leads to progressive and irreversible loss of vision. The Ahmed valve is a passive device constructed from two opposed deformable silicone elastomers sheets, commonly used for the regulation of intraocular pressure in patients with glaucoma. In this work the dynamic response of the Ahmed valve to different flow conditions and gravity test of FDA is analyzed. This is carried out by means of the numerical simulation using the Finite Element Method, considering a partitioned Fluid-Structure coupling between the fluid and the structure of the valve. The fluid is described by the incompressible Navier-Stokes equations, written in an arbitrary time dependent coordinate system and the structure is described by a constitutive linear elastic solid assuming large displacements and rotations. In order to decrease the computational cost of the simulation, a reduced order model of the system is also presented. This model is developed using data from a previous characterization process using the partitioned fluid-structure solver. With the aim to validate the numerical simulation, the results are compared with experimental ones.