The recently approved stent is implanted in conjunction with cataract surgery and is designed to decrease intraocular pressure.
On June 25, 2012, the FDA approved the iStent Trabecular Micro-Bypass Stent System
for use in patients with both a cataract and mild or moderate open-angle glaucoma who have been treated with medication for high intraocular pressure (IOP). The iStent is a 1-millimeter-long titanium tube that is inserted behind the eye (between the anterior chamber and Schlemm’s canal) to help drain fluid, with the goal of decreasing IOP. It is implanted in conjunction with cataract surgery.
, which is manufactured by the Glaukos Corporation of Laguna Hills, California, is already in use in Europe. Before approval, the FDA reviewed a study
in which 240 eyes with mild to moderate open-angle glaucoma received either cataract surgery with iStent implantation or cataract surgery alone. (The study included 239 participants, with 1 participant having both eyes evaluated.) One year after surgery, 72% of participants with the iStent reached the target IOP of 21 mm Hg or lower without medication, compared with just 50% of those who did not receive the iStent.
Among the documented complications with the iStent were failed implantation, difficult implantation, poor positioning, and blockage of the stent post-surgery. Nonetheless, the most common adverse events occurred at similar rates among those who got the iStent and those who did not.
“[The iStent] may be considered earlier in the disease process than some other types of surgical glaucoma treatments,” said Christy Foreman, director of the Office of Device Evaluation at FDA’s Center for Devices and Radiological Health, in a statement
Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.