Suzuki Shuji, Ikeda Aya, Uemura Takashi, Harada Kazuhiro, Takahashi Rie, Huang Jane, Tsukahara-Kawamura Tomoko, Ozaki Hiroaki, Kadonosono Kazuaki, Uchio Eiichi
Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, Japan.
Department of Ophthalmology, Yokohama City University Medical Center, Yokohama, Japan.
Clin Ophthalmol. 2024 May 14;18:1353-1370. doi: 10.2147/OPTH.S459925. eCollection 2024.
We studied the kinetic phenomenon of an airbag impact on eyes after trabeculectomy using finite element analysis (FEA), a computerized method for predicting how an object reacts to real-world physical effects and showing whether an object will break, to sequentially determine the responses at various airbag deployment velocities.
A human eye model was used in the simulations using the FEA program PAM-GENERIS (Nihon ESI, Tokyo, Japan). A half-thickness 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 airbag was set to hit the surface of the post-trabeculectomy eye at various velocities in two directions: perpendicular to the corneal center or perpendicular to the scleral flap (30° gaze-down position), at initial velocities of 20, 30, 40, 50, and 60 m/s.
When the airbag impacted at 20 m/s or 30 m/s, the strain on the cornea and sclera did not reach the mechanical threshold and globe rupture was not observed. Scleral flap lacerations were observed at 40 m/s or more in any eye position, and scleral rupture extending posteriorly from the scleral flap edge and rupture of the scleral flap resulting from extension of the corneal laceration through limbal damage were observed. Even in the case of 100% scleral flap adhesion strength, scleral flap rupture occurred at 50 m/s impact velocity in the 30° gaze-down position, whereas in eyes with 30% or 50% scleral flap adhesion strength, scleral rupture was observed at an impact velocity of 40 m/s or more in both eye positions.
An airbag impact of ≥40 m/s might induce scleral flap rupture, indicating that current airbags may induce globe rupture in the eyes after trabeculectomy. The considerable damage caused by an airbag on the eyes of short-stature patients with glaucoma who have undergone trabeculectomy might indicate the necessity of ocular protection to avoid permanent eye damage.
我们使用有限元分析（FEA）研究了小梁切除术后安全气囊撞击眼睛的动力学现象，FEA是一种计算机化方法，用于预测物体对现实世界物理效应的反应，并显示物体是否会破裂，以依次确定在各种安全气囊展开速度下的反应。
在使用FEA程序PAM-GENERIS（日本东京Nihon ESI公司）进行的模拟中使用了人眼模型。在角膜缘制作一个半厚度切开的巩膜瓣，并将其与外巩膜的粘连强度设置为30%、50%和100%。安全气囊设置为在两个方向上以不同速度撞击小梁切除术后的眼睛表面：垂直于角膜中心或垂直于巩膜瓣（30°向下注视位置），初始速度为20、30、40、50和60米/秒。
当安全气囊以20米/秒或30米/秒的速度撞击时，角膜和巩膜上的应变未达到机械阈值，未观察到眼球破裂。在任何眼睛位置，当速度达到40米/秒或更高时，观察到巩膜瓣撕裂，并且观察到巩膜破裂从巩膜瓣边缘向后延伸以及由于角膜裂伤通过角膜缘损伤延伸导致巩膜瓣破裂。即使在巩膜瓣粘连强度为100%的情况下，在30°向下注视位置，当撞击速度为50米/秒时也会发生巩膜瓣破裂，而在巩膜瓣粘连强度为30%或50%的眼睛中，在两个眼睛位置，当撞击速度为40米/秒或更高时均观察到巩膜破裂。
安全气囊撞击速度≥40米/秒可能会导致巩膜瓣破裂，这表明当前的安全气囊可能会在小梁切除术后的眼睛中导致眼球破裂。安全气囊对接受小梁切除术的身材矮小青光眼患者眼睛造成的严重损害可能表明有必要进行眼部保护以避免永久性眼损伤。
