Weiyi Chen

Ocular trauma can cause blinding conditions such as choroidal rupture (CR) and retinal detachment (RD). The finite element method (FEM) is widely used to evaluate ocular trauma, but the choroid is often oversimplified because of limited mechanical data, potentially reducing simulation accuracy. This study characterized choroidal mechanical properties and incorporated precise viscoelastic data into ocular trauma simulations. The elastic and viscoelastic properties of the choroid were quantified using biaxial tensile testing. These data were integrated into a finite element model of the human eye incorporating the viscoelastic choroid. BB gun projectile impact simulations were then performed at different speeds to analyze the mechanical responses of posterior ocular tissues. The principal constitutive parameters of the choroid were determined under equibiaxial loading. Simulation results demonstrated that, under identical ocular trauma conditions, inclusion of the choroid altered both scleral and retinal stresses compared with the choroid-excluded eye model, with retinal stress showing a larger change. At an impact speed of 60 m/s, the retinal stress change exceeded 43%. Moreover, the difference in maximum principal stress between the viscoelastic and linear elastic choroid models was 21%, 36%, and 70% at 20, 40, and 60 m/s, respectively. This study provides valuable reference data and a theoretical foundation for understanding the mechanical behavior of the choroid. The proposed computational model underscores the importance of viscoelastic choroid and contributes to improving the accuracy of ocular trauma modeling.

To evaluate the efficacy and safety of riboflavin-ultraviolet A scleral cross-linking surgery over time in vivo using an accelerated protocol with supplemental oxygen. This study compared accelerated scleral collagen cross-linking (A-SXL) plus 90% O2 (30 mW/cm2 for 3 minutes with 90% oxygen supplementation) to the traditional protocol (T-SXL; 3 mW/cm2 for 30 minutes) in young New Zealand White rabbits. The right eye underwent surgery, and the left eye served as an intraindividual control. At different time points, efficiency was evaluated through spherical equivalent refraction (SER), axial length (AL), and scleral tangent modulus, and safety was assessed via electroretinogram (ERG) and hematoxylin and eosin (H&E) staining. The A-SXL+90% O2 protocol significantly preserved refractive power and inhibited axial elongation over the 3-month postoperative period, and no statistically significant differences were detected when compared with the T-SXL group (P > 0.05). Moreover, the A-SXL+90% O2 protocol led to a significant increase in scleral tangent modulus at both 1 month and 3 months post-surgery, similar to the outcomes seen with T-SXL. ERG and H&E staining revealed no evidence of retinal functional impairment or histological alterations in posterior ocular tissues (sclera, choroid, and retina) in both scleral cross-linking protocols. A-SXL supplemented with oxygen offers a faster, effective, and relatively safe alternative to T-SXL in vivo by demonstrating sustained biomechanical reinforcement with an acceptable safety profile. A-SXL supplemented with oxygen may be a promising therapeutic approach for scleral weakening disorders such as progressive high myopia.