Simulation of air-bag impact on an eye with transsclerally fixated posterior chamber intraocular lens using finite element analysis.
OBJECTIVE
To determine the physical and mechanical conditions of an impacting air bag that would rupture an eye with a transsclerally fixated posterior chamber intraocular lens (IOL).


METHODS
Numerical simulation study on a computer.


METHODS
Simulations in a model human eye were performed with a computer using the finite element analysis program PAM-CRASH (Nihon ESI). The air bag was set to impact the surface of an eye with a transsclerally fixated posterior chamber IOL at various velocities. The tensile force limit of a 10-1 polypropylene suture was assumed to be 0.16 N, which is specified in the U.S. Pharmacopeia XXII.


RESULTS
At the lowest velocity of 20.0 m/s, 10-0 polypropylene sutures were not likely to break. Sutures fixating the IOL might break and a corneoscleral incision was likely to open after 0.3 second at the medium impacting velocity (30 m/s). Suture rupture was very likely at the highest velocity (40 m/s) since the tensile force on the sutures continuously exceeded the breaking force after the impact.


CONCLUSIONS
In an eye with a transsclerally fixated posterior chamber IOL, severe ocular trauma can be caused by an air bag at high velocity. Small individuals such as elderly women are at greater risk for air-bag ocular injury. Further research on modifying air-bag design and deployment is important to minimize the risk for ocular injury.
Uchio
Eiichi
E
Department of Ophthalmology, Yokohama City University Medical Center, Yokohama, Japan.
Kadonosono
Kazuaki
K
Matsuoka
Yasuhiro
Y
Goto
Satoru
S
D017278:Air Bags / Q000009:adverse effects*; D003198:Computer Simulation; D005131:Eye Injuries / Q000209:etiology* / Q000517:prevention & control; D020342:Finite Element Analysis; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008954:Models, Biological; D018918:Phacoemulsification; D011126:Polypropylenes; D012421:Rupture; D012590:Sclera / Q000601:surgery*; D013529:Surgical Wound Dehiscence / Q000209:etiology* / Q000517:prevention & control; D013536:Suture Techniques; D013537:Sutures
D011126:Polypropylenes