Spatiotemporal Mapping of Biomechanical Stress Predicts Region-Specific Retinal Injury in a Murine Model of Blunt...

Retinal detachments following blunt ocular trauma are challenging to predict due to the complex and transient biomechanical responses of the globe. This study combines an in vitro weight-drop experiment and finite element analysis (FEA) to evaluate the mechanical pathways leading to traumatic retinal detachment and to predict the spatial likelihood of injury. In the in vitro model, a cylindrical weight was impacted onto freshly enucleated mouse eyes (16 weeks old) supported on a rigid metal plate. Following impact, the eyes were sectioned and stained using hematoxylin and eosin (H&E) for histological assessment. A finite element model of a mouse eye, including the cornea, sclera, lens, zonule, vitreous body, aqueous humor, and retina, was reconstructed from the histological section and used to simulate the whole sequence of compression and rebound following the blunt impact. The simulation demonstrated that the lens retained a high momentum. It generated an alternating compressive (up to -6.57 × 10^-3 MPa) and tensile (up to 1.62 × 10^-3 MPa) radial stress at the posterior pole and sustained compressive stress at the peripheral region (up to -3.12 × 10^-3 MPa) and tensile-compressive stress variation at the equatorial region of the retina. In addition, the regions experiencing tensile stress overlapped with the region exhibiting retinal detachment in the in vitro experiment. These findings highlight the spatiotemporal mapping of biomechanical stress to predict traumatic retinal detachment following blunt impact and provide an understanding of early biomechanical response following ocular trauma.