Proposal of a new model for simulating the biomechanical effect of LASIK, SMILE and PRK on the cornea

Session Details

Session Title: Corneal Biomechanics

Session Date/Time: Tuesday 13/09/2016 | 16:30-18:00

Paper Time: 17:42

Venue: Auditorium C6

First Author: : D.Varssano ISRAEL

Co Author(s): :    R. Katzengold   D. Smadja   A. Gefen              

Abstract Details

Purpose:

To analyze the performance of a new theoretical model for simulating the biomechanical effect of LASIK, PRK and SMILE on the cornea

Setting:

Tel Aviv University, Department of biomedical engineering, Faculty of Engineering; Tel Aviv Sourasky Medical Center, Corneal and External Diseases Unit, Ophthalmology Department

Methods:

Using previously published data, a validated formulation for biomechanical properties that simulates hyperelastic stress-strain curves was applied to a corneal model derived from a patient’s corneal geometry imaged with a Placido Dual-Scheimpflug. A finite element analysis was then conducted on our model in order to simulate and analyze the effect of different level of stress, simulated by applying gradual elevation of intraocular pressure on the corneas after myopic LASIK, SMILE or PRK. Curvature maps and Effective Strain curves were derived and compared between the 3 procedures, as a result of corneal deformations when submitted to different level of stress.

Results:

Increase in intraocular pressure induced significantly higher (p<0.05) level of stress and corneal deformation after LASIK than after both PRK and SMILE. Application of 20mmHg on the treated corneas induced a significantly higher increase in stress distribution in all treated corneas as compared to the non-treated corneal model. The effective stress measured throughout the corneal tissue was respectively 0.05, 0.43 and 0.041MPa (MegaPascal) respectively after LASIK, SMILE and PRK, whereas it was measured at 0.038 in the non-treated corneal model.

Conclusions:

This new model enabled to differentiate the biomechanical impact of the three procedures for a similar level of myopic correction. As expected, significantly higher levels of effective stress and strain of the corneal tissue after LASIK than after both PRK and SMILE, were predicted by our model.

Financial Disclosure:

NONE