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Войти в исследования Journal of cataract and refractive surgery · 2001
Simulation of air-bag impact on post-radial keratotomy eye using finite element analysis.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
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Uchio E, Ohno S, Kudoh K, Kadonosono K, Andoh K, Kisielewicz L T
Аннотация
PURPOSE: To determine the physical and mechanical conditions of an impacting air bag that causes corneal rupture in a post-radial keratotomy (RK) eye using a simulation model of the human eye.
SETTING: Numerical simulation study on a computer.
METHODS: The simulations were performed by a computer using the finite element analysis program PAM-CRASH (Nihon ESI). The air bag was set to impact the surface of a post-RK eye with 4, 6, or 8 corneal incisions at various velocities. Strain on the corneal tissue including scarred incisions exceeding 9.0% was assumed to indicate the possibility of corneal rupture.
RESULTS: At a medium velocity of 30 m/s, corneal rupture was likely to occur. At an air-bag impact velocity of 40 m/s, 3 of 4, 5 of 6, and 8 of 8 incisions were likely to rupture in the case of 4-, 6-, and 8-incision procedures, respectively, leading to likely globe rupture in all situations. Lacerations extended beyond the incisions and involved the intact cornea at a velocity of 40 m/s. If the corneal tissue strength reduction was increased to 90%, most incisions were likely to rupture at impact velocities greater than 35 m/s in all incision procedures.
CONCLUSIONS: The 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 air bags at ordinary impact velocities.
SETTING: Numerical simulation study on a computer.
METHODS: The simulations were performed by a computer using the finite element analysis program PAM-CRASH (Nihon ESI). The air bag was set to impact the surface of a post-RK eye with 4, 6, or 8 corneal incisions at various velocities. Strain on the corneal tissue including scarred incisions exceeding 9.0% was assumed to indicate the possibility of corneal rupture.
RESULTS: At a medium velocity of 30 m/s, corneal rupture was likely to occur. At an air-bag impact velocity of 40 m/s, 3 of 4, 5 of 6, and 8 of 8 incisions were likely to rupture in the case of 4-, 6-, and 8-incision procedures, respectively, leading to likely globe rupture in all situations. Lacerations extended beyond the incisions and involved the intact cornea at a velocity of 40 m/s. If the corneal tissue strength reduction was increased to 90%, most incisions were likely to rupture at impact velocities greater than 35 m/s in all incision procedures.
CONCLUSIONS: The 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 air bags at ordinary impact velocities.