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Glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for vision. The key risk factor for the development and progression of this disease is increased intraocular pressure (IOP). Implantable glaucoma drainage devices have been developed to divert aqueous humor from the glaucomatous eye as a means of reducing IOP. The artificial drainage pathway created by these devices drives the fluid into a filtering bleb. The long-term success of filtration surgery is dictated by the proper functioning of the bleb and overlying Tenon's and conjunctival tissue. To better understand the influence of the health condition of these tissues on IOP, we have developed a mathematical model of fluid production in the eye, its removal from the anterior chamber by a particular glaucoma implant–the PRESERFLO® MicroShunt–, drainage into the bleb and absorption by the subconjunctival vasculature. The mathematical model was numerically solved by commercial FEM package COMSOL. Our numerical results of IOP for different postoperative conditions are consistent with the available evidence on IOP outcomes after the implantation of this device. To obtain insight into the adjustments in the implant's hydrodynamic resistance that are required for IOP control when hypotony or bleb scarring due to tissue fibrosis take place, we have simulated the flow through a microshunt with an adjustable lumen diameter. Our findings show that increasing the hydrodynamic resistance of the microshunt by reducing the lumen diameter, can effectively help to prevent hypotony. However, decreasing the hydrodynamic resistance of the implant will not sufficiently decrease the IOP to acceptable levels when the bleb is encapsulated due to tissue fibrosis. Therefore, to effectively reduce IOP, the adjustable glaucoma implant should be combined with a means of reducing fibrosis. The results reported herein may provide guidelines to support the design of future glaucoma implants with adjustable hydrodynamic resistances. [ABSTRACT FROM AUTHOR]

Glaucoma drainage devices are implanted in the eye to treat glaucoma, a disease that can cause vision loss and blindness. These devices are designed to reduce intraocular pressure (IOP), a major risk factor for the progression of glaucoma, by providing an alternative outflow path for the fluid produced by the eye, the aqueous humor. Here, a novel polymeric minimally invasive glaucoma implant designed to enhance aqueous humor outflow is demonstrated. The implant is made of a unique, potentially biodegradable thermoplastic material, polycarbonate bisamide (PC‐BA), and produced through replica molding using hot embossing and femtosecond laser‐machined glass molds. Post‐mortem experiments demonstrate successful device implantation into a rabbit's eye, with the implant remaining securely in place. Although the mass loss and changes in molecular weight observed in the in vitro degradation experiments are not significant within the tested times and degradation conditions, the PC‐BA is a slow‐degradation polymer that may take a few years to fully degrade. Thus, the implant will also slowly degrade and be absorbed by the body over time, leaving behind a natural outflow pathway. This potentially biodegradable glaucoma implant may represent a promising new approach for restoring outflow in a more natural way. [ABSTRACT FROM AUTHOR]