3D SOLID INCOMPRESSIBLE VISCOELASTIC FINITE ELEMENT IN LARGE STRAINS FOR THE CORNEA. REFRACTIVE SURGERY APPLICATION

FABIO A. GUARNIERI Y ALBERTO CARDONA

MECANICA COMPUTACIONAL

CIMNE

Lugar: Barcelona; Año: 1998 vol. 19 p. 1 - 17

Several models1{3 have been developed in order to reproduce the corneal behav- ior in ophthalmological procedures as tonometry, radial keratotomy and photokeratectomy with Excimer Laser. It has been found that the viscoelastic eect of a biological soft tis- sue, as the cornea, is negligible in tonometry.3 Nevertheless, clinical studies on humans showed refractive changes with time in radial keratotomy. Wound healing is responsible for the long time eect (measured in years). On the other hand, the short-time eect (hours or days) has not been claried. In this work a 3D viscoelastic nite element model is developed taking into account incompressibility and large strains. An internal variable is introduced by means of a multiplicative decomposition of the deformation gradient. The nal goal of the study is to determine the importance of the viscoelastic eect in the Refractive Surgery.