Micro-invasive glaucoma surgery: current perspectives and future directions

Purpose of review There is an increasing interest and availability of micro-invasive glaucoma surgery (MIGS) procedures. It is important that this increase is supported by sound, peer-reviewed evidence. This article will define MIGS, review relevant publications in the period of annual review and discuss future directions. Recent findings The results of the pivotal trial comparing a trabecular micro-bypass stent (iStent, Glaukos Corporation, Laguna Hills, CA, USA) combined with phacoemulsification to phacoemulsification alone showed a significantly higher percentage of patients with unmedicated intraocular pressure (IOP) < 21 mmHg, and a comparable safety profile. Initial results are published regarding a second-generation micro-bypass stent (iStent inject, Glaukos Corporation, Laguna Hills, CA, USA), a canalicular scaffold (Hydrus, Ivantis Inc., Irvine, CA, USA) and an ab interno suprachoroidal microstent (CyPass, Transcend Medical, Menlo Park, CA, USA), showing a decrease in mean postoperative IOP. Phaco-Trabectome (Ab interno trabeculectomy Trabectome, NeoMedix Inc., Tustin, CA, USA) was compared to phacotrabeculectomy and showed less IOP reduction, less postoperative complications, and a similar success rate. Similar success rates were found with the comparison of excimer laser trabeculostomy (ELT, AIDA, Glautec AG, Nurnberg, Germany) and selective laser trabeculoplasty. A number of publications review the importance of the location of implantable devices, intraoperative gonioscopy, cost-effectiveness and quality-of-life studies, and randomized clinical trials. Summary MIGS procedures offer reduction in IOP, decrease in dependence on glaucoma medications and an excellent safety profile. Their role within our glaucoma treatment algorithm continues to be clarified and differs from the role of more invasive glaucoma surgeries such as trabeculectomy or glaucoma drainage devices.