Abstract Minimally invasive glaucoma surgery (MIGS) has transformed the surgical management of mild-to-moderate glaucoma by lowering intraocular pressure (IOP) with a favorable safety profile. Accurate intraoperative visualization of the anterior chamber angle (ACA) via gonioscopy is fundamental to the success of ab-interno angle procedures. This review synthesizes the optical principles underpinning gonioscopy, compares contemporary surgical lenses (direct, indirect, and upright designs), and outlines practical recommendations for intraoperative setup, patient selection, and troubleshooting. We highlight critical landmarks (e.g., scleral spur, trabecular meshwork pigmentation, Schlemm’s canal reflux) and discuss adjuvants, such as trypan blue for trabecular meshwork staining. By aligning lens selection with the intended procedure and optimizing the operative ergonomics, surgeons can enhance visualization, reduce complications, and improve outcomes.
Velikova et al. (2026) studied this question.