Response of a passive glaucoma drainage device to different flow conditions

SASSETTI FERNANDO LEONEL; GARELLI LUCIANO; GUARNIERI FABIO ARIEL

Rosario

Congreso; ENIEF 2011; 2011

AAMCA

Glaucoma is an eye disease that causes ocular nerve damage and is characterized by the rise of intraocular pressure above the normal limits. 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 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 presented. This model is developed using data from a previous characterization process. With the aim to validate the numerical simulation, the results are compared with experimental ones. Finally, is determined that due to the characteristic time of structure is possible to represent the behavior of the valve by a reduced order model, which can then be either coupled to other models, such as a 0D  eye’s model.