Abstract
Purpose :
One of the most common reasons for blindness is glaucoma. The primary risk factor for the development of the vision loss in glaucoma is an increased intraocular pressure (IOP) and lowering the IOP is currently the only therapeutic option with proven efficiency. To predict the pressure drop after trabeculectomy and stent insertion, a mathematical model is developed. Using this model, IOP and aqueous humor flow is computed for a healthy eye, a pathological eye and a treated eye.
Methods :
The mathematical model is given by Stokes equation with a Neumann boundary condition induced by the Darcy equation. Numerical simulations of the model are performed with the help of the Finite Element Method in three dimensions. The simulation is generated with an in-house software library.
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Results :
The simulation shows that change of the permeability from 10E-15 to 10E-16 m^2 leads to an increase of the IOP from 9 mmHg to 25 mmHg. For the healthy eye a linear dependency between the episcleral vein pressure (EVP) and IOP is observed: IOP=EVP+1.2 mmHg (where permeability is given by 10E-15 m^2). First simulations of glaucoma treatment with a stent of approximately 6mm predict a pressure drop of 6 mmHg in the case of an pathological eye with the IOP of 50 mmHg.
Conclusions :
Computational results confirm that trabeculectomy and the stent insertion leads to a decrease of the IOP. Occlusion in the trabecular meshwork leads to noticeable increase of the IOP. Moreover, the simulations may predict the outcome of the therapies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.