Ocular injury mechanics under blunt and shock wave impact: a review
摘要
This review summarizes the mechanical properties of key ocular structures (cornea, sclera, lens, and vitreous) and systematically evaluates the measurement techniques and data discrepancies. We review here experimental methods for ocular injury loading and three types of injury models: isolated eyeball model, orbit-eyeball model, and head-eyeball model. The construction of numerical ocular models and their application in simulation experiments are analyzed. Based on experimental and simulation results, for blunt eye injuries, the severity of the impact and the resulting damage are influenced by factors such as the mass of the impacting object, its velocity at the time of impact, and the contact area with the eye. For instance, larger masses, higher velocities, and smaller contact areas tend to cause more severe injuries, often extending to the posterior segment of the eye. Therefore, we categorized impactors into less than orbit (LOI) and greater than orbit (GOI), examining their distinct deformation patterns and injury characteristics during loading. For explosive impacts, we analyzed the shockwave propagation path and pressure distribution across structures to elucidate the corresponding injury mechanisms. We further established an eye injury assessment index based on speed and overpressure. The eye rupture thresholds for LOI and GOI are set at 60 and 30 m/s respectively; for shock wave loading, when the overpressure exceeds 0.25 MPa, it will cause relatively severe damage, while when the overpressure is greater than 0.6 MPa, it may lead to severe injuries such as eye rupture. Additionally, recommendations for optimizing measurement, experimental, and simulation methods are provided for future research.