Complications of micro-invasive glaucoma surgery

Purpose of review Micro-invasive glaucoma surgery (MIGS) is gaining favor with both comprehensive ophthalmologists and glaucoma specialists due in part to its improved safety profile when compared to traditional incisional glaucoma surgery. Despite a micro-invasive approach and minimal induced tissue trauma, each MIGS procedure is associated with unique complications. The present article summarizes evidence from the 2016 to 2017 review period regarding the safety profiles of Schlemm's canal-based, suprachoroidal, and subconjunctival microstents. Recent findings Ab-interno microstents are subject to intraoperative malpositioning, which can result in luminal obstruction and decreased efficacy. Acutely elevated intraocular pressure (IOP) has been observed with the iStent (Glaukos Corp., Laguna Hills, CA, USA; 2-4.3%), Hydrus Microstent (Ivantis Inc., Irvine, CA, USA; 6%), Cypass Microstent (Alcon, Fort Worth, TX, USA; 3-10.8%), and Xen Gel Stent (Allergan Plc, Dublin, Ireland; 21.5%). Meanwhile, most cases of hypotony (IOP < 6 mmHg) occurred within the first postoperative month, resolved with conservative treatment and without further surgical intervention, and were not associated with vision-threatening sequelae. Summary Interest in MIGS continues to grow as these procedures allow surgeons to intervene earlier in the disease course for patients with milder stages of glaucoma. Complications associated with MIGS, albeit infrequent and mostly transient, do occur despite a less invasive approach than trabeculectomy and tube shunt surgery.