New devices to lower IOP and facilitate aqueous outflow via minimally invasive glaucoma surgery are being developed, and early results from clinical trials are favorable for some.
Chicago—A number of investigational implant devices for managing glaucoma are in the pipeline, and preliminary clinical trial data are promising for some, said Angelo P. Tanna, MD, vice chairman, Department of Ophthalmology, and director of the Glaucoma Service, Northwestern University Feinberg School of Medicine, Chicago.
Dr. Tanna reviewed several stents developed for microinvasive glaucoma surgery (MIGS), assessing the as-yet limited data on relative efficacy and safety.
The investigational implants lower IOP by shunting aqueous humor to the subconjunctival space, directly to Schlemm’s canal, or to the suprachoroidal space. For the subconjunctival space, one device under development is the XEN gel stent from AqueSys.
This collagen stent, using an ab interno approach, is 6 mm long and about the width of a human hair. It is injected through a self-sealing corneal incision using a preloaded injector. AqueSys has an approved investigational device exemption and is enrolling subjects for clinical trials.
Two devices that shunt aqueous directly to Schlemm’s canal are the iStent inject (Glaukos) and the Hydrus Microstent (Ivantis). The iStent inject (GTS 400) is much smaller than the current FDA-approved product, 400 by 300 µm, Dr. Tanna said.