Abstract
Abstract: :
Purpose:A simulation model of the human eye which we developed was applied to simulated airbag ocular injury, to determine the physical and mechanical conditions of the impacting airbag causing corneal rupture in a post-radial keratotomy (RK) eye. Methods:The simulations were performed by a computer using the finite element analysis program. The airbag was set to impact on the surface of the post-RK eye, with 4, 6 or 8 corneal incisions for comparative study, at various velocities. Strain on the corneal tissue including scarred incisions exceeding 9.0% was assumed to indicate the possibility of corneal rupture in this study. Results:At a medium velocity of 30.0 m/sec, it was observed that corneal rupture was likely to occur. At an airbag impact velocity of 40.0 m/sec, 3 of 4, 5 of 6 and 8 of 8 incisions were likely to rupture in the case of 4-, 6- and 8-incision procedure, respectively, leading to very likely globe rupture in all situations. It was also observed that lacerations extended beyond the incisions and involved the intact cornea at a velocity of 40.0 m/sec. If the corneal tissue strength reduction was increased to 90%, the majority of incisions were likely to rupture at impact velocities more than 35.0 m/sec in all incision procedures. Conclusion:These results could partly reflect a reported case of globe rupture after RK, and suggest that severe ocular trauma can be caused in the post-RK eye by airbags even at ordinary impact velocities.
Keywords: 544 refractive surgery • 608 trauma • 369 cornea: clinical science