Innovations in glaucoma treatment: development and testing of a novel self-adjustable implant for effective pressure regulation

Glaucoma drainage devices (GDDs) are widely used to lower intraocular pressure (IOP) and slow disease progression; however, existing designs often lack intrinsic protection against early postoperative hypotony, show limited adaptability to evolving distal outflow resistance during bleb maturation, and rely on bulky or complex components that constrain implantation and MRI compatibility. Here, we present a compact, fully passive, self-adjustable glaucoma implant designed to maintain IOP within the physiological range by dynamically modulating its hydraulic resistance without external control or postoperative adjustment. The device consists of a circular microvalve incorporating a thin, pre-stressed compliant membrane that responds to pressure conditions at the inlet and outlet. Valve performance was investigated using fully coupled fluid-structure interaction (FSI) simulations and parametric analyses, followed by fabrication and in vitro characterization, and ex vivo assessment of surgical feasibility in enucleated porcine eyes. The results demonstrate effective pressure regulation across physiologically relevant conditions, with mitigation of early hypotony and attenuation of pressure elevation under increasing downstream resistance. Ex vivo implantation confirmed ease of placement, appropriate anatomical fit, and compatibility with standard surgical workflows. Owing to its compact form factor, passive operation, and simplified, cost-effective design, the proposed implant addresses key limitations of current GDDs and shows strong potential for clinical translation.