Laser-responsive shape memory device to program the stepwise control of intraocular pressure in glaucoma

Abstract

Clinical laser systems enable user-specified control of the energy level, focus, and frequency by minimizing untargeted influences, which has never been applied to implantable shape memory polymers (SMPs). The glaucoma clinic possesses multi-decade issues to control progressive fluctuations in intraocular pressure (IOP) with tissue fibrosis upon implantation of silicone drainage devices. As a translatable device, we applied a laser-responsive SMP to develop i) a tube with intimal gel coating to release anti-fibrotic drugs and ii) safety lock ring. When the SMP tube was inserted into a silicone tube with wrapping externally by the ring, intimal gel degradation and argon laser-triggered diameter increase enabled three-step IOP control. Sustained drug release of the intimal gel suppressed tissue fibrosis, and the ring prevented late hypotonic IOP by externally squeezing the silicone tube. The unprecedented design and functions were validated using computational, in vitro, and rabbit glaucoma models by determining clinic-friendly argon laser parameters.