Numerical simulation of fluid–structure interaction between aqueous humor and implantable collamer lens

Understanding the biomechanical stability of the implantable collamer lens (ICL) within the aqueous humor (AH) flow is critical for long-term clinical safety. While previous hydrodynamics studies often treated the lens as a rigid body, this research employs a fluid–structure interaction method to rigorously evaluate both the AH dynamics and the resulting ICL deformation. To ensure the reliability of the numerical predictions, a scaled-up 3D-printed physical model was constructed to experimentally validate the intraocular flow patterns. This study analyzed the effects of physiological factors, including gravity direction and intraocular temperature differences, on the lens's mechanical response. The results indicate that the central hole of the ICL serves as the primary drainage pathway, diverting over 90% of the AH outflow. Although the average flow velocity peaks in the horizontal position (previously “looking flat”), the maximum lens deformation occurs during downward gaze (previously looking down), reaching 5.41 × 10−4 mm. Despite these variations, the deformation magnitude remains orders of magnitude below clinical safety thresholds. These findings confirm that the ICL maintains robust mechanical stability under varying postures and thermal conditions, providing validated biomechanical evidence that complements clinical observations.