[Simulation of airbag impact on eyes after trabeculectomy by finite element analysis method].

Purpose: A finite element computer model of the human eye after trabeculectomy was used in an experiment of simulated airbag ocular injury.

Methods: A half-layer-incised scleral flap was created on the limbus and the strength of its adhesion to the outer sclera was set at 30%, 50% and 100%. The simulations were performed at a workstation using the finite element analysis program PAM CRASH (Nihon ESI, Tokyo, Japan), and the airbag was set to hit the surface of the post-trabeculectomy eye at various velocities in two directions, straight to the corneal center or straight to the scleral flap.

Results: In the case of airbag impact on the corneal center, the scleral flap was unlikely to rupture except when the airbag impact velocity was 40 m/sec. In the case of airbag impact on the scleral flap, at the lowest impact velocity of 20 m/sec, partial scleral flap rupture was likely to occur only at the lower adhesion strength, and scleral laceration extending to the posterior sclera was observed at impact velocities of over 30 m/sec.

Conclusions: These simulation results suggest that current airbags may induce globe rupture in eyes after trabeculectomy treatment.