Current drainage devices for glaucoma: biological challenges and design concepts

Abstract

The goal of glaucoma treatment is to preserve patients’ vision and quality of life by preventing the progression of glaucomatous optic neuropathy and minimizing associated adverse effects. This is achieved by maintaining an appropriate level of intraocular pressure, stabilizing the retinal nerve fiber layer, and preventing visual field loss. Treatment options available for patients with open-angle glaucoma include: medication, laser trabeculoplasty, and incisional glaucoma surgery. An essential component of surgical treatment for glaucoma is the use of drainage devices. Subconjunctival micro-shunts, Schlemm’s canal restoration devices, suprachoroidal drainage systems, and conventional plate-based implants have all been developed as a result of major advances in implant design. A systematic review of the literature was conducted on studies published between 2015 and 2025. The analysis shows that, although different types of implants use different aqueous humor drainage pathways, the key factor influencing long-term efficacy remains biological in nature. The conceptual classification also includes the valve-equipped antiglaucomatous shunt developed at the Department of Ophthalmology of “Nicolae Testemitanu” SUMPh, which can be considered a drainage device with partial flow regulation at the implant level via an integrated valve mechanism. The proposed shunt represents a conceptual attempt to partially transfer resistance regulation from the biological capsule to flow control at the implant level. Although this approach appears promising from a theoretical prespective, further experimental and clinical studies are required to evaluate its long-term safety and efficacy.