Geometrical modelling of corneal structure in non-pathological initial conditions. A comparative study

Modelling and numerical simulation have involved a great advance in clinical practice for the prediction of the structural behaviour of soft tissues in certain healthy or pathological scenarios. One of the main features of these simulations is that they can define the geometric parameters of the structure in its initial boundary conditions. In the case of the cornea, there are discrepancies with respect to the initial conditions that depend on whether if it is considered its physiological geometry measured in vivo, or otherwise its geometry in its stress-free state. The choice of one or the other could lead to errors in the simulation model due to the non-linearity of these tissues. In this study, two methodologies were evaluated, the displacement method and the prestress method, to obtain the geometry of non-pathological cornea in its free-of-stress state. Both methodologies allow obtaining the physiological geometry measured in-vivo of the healthy cornea, however, the method of displacements presents a computational architecture that makes it more efficient in numerical simulation, when compared to the pre-stress method.