Subconjunctival microinvasive glaucoma surgeries: an update on the Xen gel stent and the PreserFlo MicroShunt

This review will provide an update on surgical techniques, outcomes, and complications for two new translimbal bleb-forming surgical glaucoma devices.

The XEN Gel Microstent and PreserFlo MicroShunt comprise a category of subconjunctival microinvasive glaucoma surgery developed with the aim of improving the predictability and safety profile of bleb-forming procedures. Both devices are made of noninflammatory material which limits postsurgical inflammation and scarring and have a valve-less intrinsic flow-limiting design, which decreases the risk of hypotony. There are various techniques of implantation for the XEN Gel Microstent each with their own advantages and disadvantages.

These devices have demonstrated promising outcomes in early experimental literature with similar intraocular pressure-lowering effects to traditional incisional surgery such as trabeculectomy or tube shunt surgery, but with fewer risks. Future randomized, prospective studies should be done to compare these gel stents and microshunts both to each other and to other traditional glaucoma surgeries.