Aqueous humor dynamics with a passive valve glaucoma drainage device post-implantation

Glaucoma, an irreversible ocular disease with a risk of blindness, is often treated with glaucoma drainage device (GDD) implantation as a last resort. The study on the impact of passive valve GDD implantation on aqueous humor (AH) dynamics is of great significance for supplementing numerical simulation methods for GDDs and exploring novel glaucoma treatment approaches. Therefore, this study employed a porous region method to simulate the regulatory role of the trabecular meshwork in intraocular pressure (IOP), establishing a glaucoma model. Based on this, a multi-outlet, passive valve GDD was designed and virtually implanted, with the post-implantation flow field simulated using mesh deformation, overset mesh, and fluid–structure interaction methods. Results indicate that by adjusting the structural parameters of the GDD, IOP can be maintained within an acceptable range. The thickness (h) of the upper component has a more significant impact on the IOP and outlet flow distribution ratio than the distance (d) between the drainage tube's central axis and the drainage groove. Both increases in h and d lead to increased IOP, gradually approaching pre-implantation levels. The fissure region formed by the deformation of the upper component and the trabecular meshwork region work together to regulate IOP in the simulation. However, the fissure region shows a greater height near the center of the shunting tube, potentially imposing additional mechanical stress on ocular tissues, reaching up to 5.8 μm for a GDD with h = 10 and d = 160 μm. Additionally, wall shear stress on the iris near the shunting tube inlet is relatively high, reaching values of 6.24 × 10−4 Pa under the same conditions. In conclusion, the designed GDD effectively controls postoperative IOP. Studying AH regulation performance after GDD implantation provides a foundation for the personalized customization of passive valve-type GDDs.