MODERN APPROACHES TO SUSTAINED INTRAOCULAR PRESSURE REDUCTION: A COMPREHENSIVE SYSTEMATIC REVIEW OF CONTEMPORARY MINIMALLY INVASIVE GLAUCOMA DRAINAGE IMPLANTS

Purpose: To critically appraise contemporary glaucoma drainage implants (GDIs) and minimally invasive glaucoma surgery (MIGS) with respect to sustained intraocular pressure (IOP) reduction and safety in adult glaucoma patients. Methods: A PRISMA-informed systematic review was conducted across PubMed, Scopus, and Web of Science for studies (2015–2025) reporting clinical outcomes of GDIs and MIGS. Eligible studies included adult populations with ≥6 months follow-up, reporting IOP reduction, medication use, and complications. Results: Fifteen clinical studies were included, covering Ahmed and Baerveldt implants, PAUL Glaucoma Implant, EX-PRESS, XEN Gel Stent, Hydrus, iStent, MINIject, PRESERFLO MicroShunt, and STARflo. Valved GDIs (e.g., Ahmed) offered lower hypotony risk but greater bleb encapsulation, while non-valved GDIs achieved stronger IOP reduction at the expense of early hypotony. MIGS procedures demonstrated favourable safety and quicker recovery but provided moderate IOP reduction, making them best suited for mild-to-moderate glaucoma. Emerging devices such as PAUL and MINIject showed encouraging short-term results but require long-term validation. Conclusions: GDIs remain essential in advanced or refractory glaucoma, whereas MIGS expand options for earlier disease stages with better safety. Individualised implant choice, guided by disease severity and patient profile, is crucial. Future progress lies in improving flow-control mechanisms, antifibrotic strategies, and biocompatible designs to enhance long-term success.