Minimally invasive glaucoma surgery in the surgical landscape of primary angle closure glaucoma: Current innovations...

Primary angle-closure glaucoma (PACG) is a major cause of irreversible blindness worldwide, with the highest burden in Asia. Its pathogenesis involves the interplay of multiple mechanisms, including pupillary block, plateau iris configuration, lens-related crowding, and dynamic choroidal expansion. Traditional surgical management has relied on trabeculectomy, lens extraction, or transscleral cyclophotocoagulation, which often achieve substantial intraocular pressure (IOP) control but carry significant risks and require prolonged recovery. Minimally invasive glaucoma surgery (MIGS) expands treatment options for PACG once angle access is restored. It offers safer, earlier, and targeted interventions tailored to the underlying mechanisms. Techniques range from trabecular meshwork (TM) and Schlemm's canal-based procedures to subconjunctival stents and ciliary body approaches. Combined with lens extraction, these methods deepen the anterior chamber, release peripheral anterior synechiae, and restore physiological outflow, with clinical evidence showing 20-50% IOP reductions and reduced medication burden. This paper reviews anatomical, physiological, and clinical evidence for the use of MIGS in PACG, discussing how these procedures can complement, or in selected cases replace, invasive filtration surgery, potentially enabling earlier intervention while maintaining a favorable safety profile. Future advancements will hinge on device refinements for narrow-angle eyes, imaging-guided precision, biologic modulation, and strategies to enhance cost-effectiveness and accessibility, ultimately enabling individualized, mechanism-based treatment pathways.