Suprachoroidal shunts for treatment of glaucoma A comparison based on numerical simulations

Purpose – The purpose of this paper is to compare the fluid dynamic performance of two Aqueous Humor (AH) ocular drainage devices, the SOLX® Gold Micro Shunt (GMS) and the novel Silicon Shunt Device (SSD), implanted by surgeons in human eyes to reduce the IntraOcular Pressure towards physiological values, by draining the AH from the Anterior Chamber to the Suprachoroidal Space, to cure eyes with glaucoma. Design/methodology/approach – The generalized porous medium model is solved to simulate the AH flow through the two ocular drainage devices and the surrounding porous tissues of the eye. Findings – In the GMS, probable stagnation regions have been found, due to the very small AH velocity values inside the device and to the surrounding tissues, creating possible blockage and malfunction of the device. The simple microtubular geometry of the novel SSD allows to have a regular AH flow and to choose shunts with different diameters and/or with the presence of radial holes, based on patient needs, with consequent reduction of post-operative complications. Research limitations/implications – The present model will be further developed taking into account the insertion of the present drainage devices inside the anterior section of the eye. The present results show the comparative fluid dynamic performance of the two shunts considered, and can be useful for surgeons to choose the adequate shunt, based on the required AH flow rate for a specific patient. Practical implications – The present numerical approach, employing the generalized porous medium model, represents a useful tool to study the fluid dynamics of ocular drainage devices and to design these shunts, to reduce post-operative complications. Originality/value – The generalized porous medium model is here applied for the first time to simulate the interaction of ocular drainage devices with the surrounding porous tissues of the eye.