A Systematic and Narrative Review of Safety and Complications in Minimally Invasive Glaucoma Surgery (MIGS) Between 2014–2024

Kevin Gillmann,1,2 Christophe Baudouin,3– 5 Imran Masood,6– 8 Ana Miguel,9,10 Alice Grise-Dulac,11 Nishani Amerasinghe,12 Karl Mercieca,13 Cedric Gillmann,14 Athena Lallouette1 1Department of Ophthalmology, Genève Ophtalmologie, Geneva, Switzerland; 2School of Business and Management, Queen Mary University of London, London, UK; 3Department of Ophthalmology 3, Quinze-Vingts National Ophthalmology Hospital, IHU FOReSIGHT, Paris, France; 4Department of Ophthalmology, Ambroise Paré Hospital, IHU Foresight, AP-HP, University of Paris Saclay, Boulogne-Billancourt, France; 5IHU Foresight, INSERM-DGOS CIC 1423, Institut de la Vision Sorbonne Université, Paris, France; 6Department of Ophthalmology, Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, United Kingdom; 7Department of Ophthalmology, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; 8Department of Ophthalmology, Birmingham Institute for Glaucoma Research, Institute of Translational Medicine, University Hospital Birmingham, Birmingham, UK; 9Department of Ophthalmology, Centre Hospitalier Universitaire de Caen, Caen, France; 10Department of Ophthalmology, Hôpital Privé de la Baie, Avranches, France; 11Department of Anterior Segment and Refractive Surgery, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France; 12Department of Ophthalmology, University Hospitals Southampton NHS Trust, Southampton, UK; 13Department of Ophthalmology, University of Bonn, Bonn, Germany; 14Department of Earth and Planetary Sciences, ETH Zurich, Zurich, SwitzerlandCorrespondence: Kevin Gillmann, Department of Ophthalmology, Genève Ophtalmologie, Avenue du Mail 22, Geneva, 1205, Switzerland, Email [email protected]: Earlier intervention in glaucoma has been suggested to slow disease progression and preserve visual function and quality of life. Consequently, minimally invasive glaucoma surgery (MIGS) is increasingly used in mild-to-moderate glaucoma. Although numerous techniques and devices are available, their comparative efficacy remains debated: most procedures lower intraocular pressure to the mid-teens in primary open-angle glaucoma, but without clear evidence of superiority. As these surgeries are now offered to younger, otherwise healthy patients, safety has therefore become a central criterion in technique selection.Methods: This PRISMA-based systematic review analyzed safety outcomes from peer-reviewed studies of the main MIGS procedures published between 2014 and 2024. Five databases were searched using current and historical device names. Non-clinical studies, case series, and nonstandard techniques were excluded from quantitative analysis but retained qualitatively to capture rare events. A total of 401 studies, representing 39,381 eyes and 68,917 eye-years of follow-up, were included. Highest reported and weighted mean complication rates were calculated by procedure type.Results: Safety profiles varied. Trabecular bypass implants and ab interno canaloplasty were associated with low rates of serious adverse events and minimal anatomical disruption. Suprachoroidal devices carried higher risks of hypotony, inflammation, and malposition. Across all categories, chronic changes to angle anatomy and occasionnal re-interventions highlighted the potential for long-term sequelae, with endothelial cell loss emerging as a key concern for certain procedures.However, heterogeneity in definitions and reporting limited comparability. Common events such as hyphema and IOP spikes were inconsistently documented, while late complications like endothelial cell loss or peripheral anterior synechiae were often overlooked. This underreporting risks conflicting conclusions and undermines comparisons.Conclusion: For patients with mild, stable disease or those undergoing opportunistic combined surgery, tissue-sparing procedures with the lowest observed complication rates may be preferable. Standardized definitions, long-term follow-up, and harmonized safety reporting are becoming essential.Keywords: glaucoma, adverse events, canaloplasty, trabecular bypass, goniotomy, endothelial cell loss