title: Simulation of air-bag impact on an eye with transsclerally fixated posterior chamber intraocular lens using finite element analysis.
abstract: 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.
authors.affiliation: Department of Ophthalmology, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Uchio
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kadonosono
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: Satoru
authors.initials: S
authors.lastname: Goto
mesh_terms: 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
chemical_list: D011126:Polypropylenes