2020/11/02 | Research | Biomechanics

Corneal biomechanics after ring implantation

Intrastromal rings can be introduced into the corneal stroma to correct high refractive errors such as severe myopia or keratoconus. In collaboration with the Aragón Institute for Engineering Research in Zaragoza, Spain, the ARTORG Computational Bioengineering group has investigated corneal biomechanics after intrastromal ring implantation. Their numerical study found that implants do not stiffen the cornea but create a local bulkening effect that regularizes the corneal shape.

Diagram of corneal kinematics and mechanics after ring implantation based on FE simulations (from M. Ariza-Gracia et al., https://doi.org/10.1167/tvst.9.11.26)


Researchers investigated four different corneal topologies using calibrated in silico models to determine the corneal shape and stresses after ring implantation, as well as geometric ray-tracing to characterize the change induced by the rings on the visual outcome. Models predicted the postsurgical optomechanical response of the cornea at a population level. Central corneal stresses did not increase by more than 50%, and thus implants did not strengthen the cornea globally. 

Because of the higher amount of biomechanical weakening introduced by laser pocketing, continuous implants in a pocket resulted in higher refractive corrections than ring implants placed inside a corneal "tunnel". The authors also concluded that in silico models can help to understand corneal biomechanics, to plan patient-specific interventions, or to create biomechanically driven nomograms.


Link to study

Computational Bioengineering