Ueno Tomohiro, Fujita Hideaki, Ikeda Aya, Harada Kazuhiro, Tsukahara-Kawamura Tomoko, Ozaki Hiroaki, Uchio Eiichi
Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, Japan.
Clin Ophthalmol. 2024 Mar 7;18:699-712. doi: 10.2147/OPTH.S445253. eCollection 2024.
We studied the kinetic phenomenon of an airbag impact on eyes with different axial lengths using finite element analysis (FEA) to sequentially determine the physical and mechanical responses of intraocular segments at various airbag deployment velocities.
The human eye model we created was used in simulations with the FEA program PAM-GENERIS. The airbag was set to impact eyes with axial lengths of 21.85 mm (hyperopia), 23.85 mm (emmetropia) and 25.85 mm (myopia), at initial velocities of 20, 30, 40, 50 and 60 m/s. The deformation rate was calculated as the ratio of the length of three segments, anterior chamber, lens and vitreous, to that at the baseline from 0.2 ms to 2.0 ms after the airbag impact.
Deformation rate of the anterior chamber was greater than that of other segments, especially in the early phase, 0.2-0.4 ms after the impact (P < 0.001), and it reached its peak, 80%, at 0.8 ms. A higher deformation rate in the anterior chamber was found in hyperopia compared with other axial length eyes in the first half period, 0.2-0.8 ms, followed by the rate in emmetropia (P < 0.001). The lens deformation rate was low, its peak ranging from 40% to 75%, and exceeded that of the anterior chamber at 1.4 ms and 1.6 ms after the impact (P < 0.01). The vitreous deformation rate was lower throughout the simulation period than that of the other segments and ranged from a negative value (elongation) in the later phase.
Airbag impact on the eyeball causes evident deformation, especially in the anterior chamber. The results obtained in this study, such as the time lag of the peak deformation between the anterior chamber and lens, suggest a clue to the pathophysiological mechanism of airbag ocular injury.
我们使用有限元分析（FEA）研究了安全气囊对不同眼轴长度眼睛的冲击动力学现象，以依次确定在不同安全气囊展开速度下眼内各节段的物理和力学响应。
我们创建的人眼模型用于FEA程序PAM - GENERIS的模拟。安全气囊被设定以20、30、40、50和60米/秒的初始速度冲击眼轴长度分别为21.85毫米（远视）、23.85毫米（正视）和25.85毫米（近视）的眼睛。变形率计算为安全气囊冲击后0.2毫秒至2.0毫秒内前房、晶状体和玻璃体三个节段的长度与基线长度的比值。
前房的变形率大于其他节段，尤其是在冲击后的早期阶段，即0.2 - 0.4毫秒（P < 0.001），并在0.8毫秒时达到峰值80%。在前半段时间，即0.2 - 0.8毫秒内，远视眼的前房变形率高于其他眼轴长度的眼睛，其次是正视眼（P < 0.001）。晶状体变形率较低，其峰值在40%至75%之间，并在冲击后1.4毫秒和1.6毫秒时超过前房的变形率（P < 0.01）。在整个模拟期间，玻璃体的变形率低于其他节段，并且在后期阶段为负值（伸长）。
安全气囊对眼球的冲击会导致明显的变形，尤其是在前房。本研究获得的结果，如前房和晶状体峰值变形之间的时间滞后，为安全气囊眼部损伤的病理生理机制提供了线索。
