Should Schlemm Canal-Based MIGS Be Combined with Cataract Surgery in Patients Receiving Topical Glaucoma Therapy? A Cataract Surgeon-Oriented Review

Background/Objectives: Schlemm canal-based minimally invasive glaucoma surgery (MIGS) can be combined with cataract surgery, but topical glaucoma therapy alone is not a sufficient indication for adding MIGS. This review addresses when cataract surgery alone may be sufficient, when combined cataract surgery and MIGS may be appropriate, and when filtration surgery should be considered. Methods: This narrative review used a targeted PubMed/MEDLINE search of English-language literature published from January 2000 to May 2026 to support source identification and reference selection. The review focused on cataract surgery combined with Schlemm canal- or trabecular meshwork-targeted MIGS, including stent-based Schlemm canal procedures and trabeculotomy/goniotomy-based procedures, medication burden, ocular surface disease, refractive and visual outcomes, corneal endothelial safety, complications, angle visibility, guideline-based decision-making, and patient selection. Final references were selected according to clinical relevance to cataract-surgeon decision-making and evidence priority, with emphasis on guidelines, systematic reviews or meta-analyses, randomized or prospective comparative studies, pivotal or long-term studies, large real-world or post-market studies, and clinically informative safety, refractive, endothelial, imaging, or complication-related studies. Results: Stent-based Schlemm canal procedures and trabeculotomy/goniotomy-based procedures can provide additional IOP and medication reduction compared with cataract surgery alone in selected eyes with mild-to-moderate open-angle glaucoma. Stent-based procedures generally have a lower hyphema risk, whereas trabeculotomy/goniotomy-based procedures may provide comparable or greater IOP reduction in selected eyes but are associated with more frequent hyphema. In normal-tension glaucoma or low-baseline-IOP eyes, the expected benefit is often medication reduction or modest IOP lowering rather than reliable achievement of very low target IOP. Available refractive evidence remains limited and procedure-specific, but suggests that major refractive instability is uncommon in appropriately selected eyes. Conclusions: The decision to combine Schlemm canal-based MIGS with cataract surgery should be goal-directed rather than based solely on the presence of topical therapy. Practical selection should integrate glaucoma subtype, disease stage, baseline and target IOP, expected phacoemulsification-only IOP reduction, medication burden, ocular surface status, adherence, angle visibility, endothelial reserve, refractive objectives, and future filtration surgery options.