iStent inject safe, efficacious in open-angle glaucoma
Click Here to Manage Email Alerts
The iStent inject was safe and effective for treating multiple types of primary open-angle glaucoma individually and in conjunction with cataract surgery, according to data published in Journal of Cataract and Refractive Surgery.
“Elevated [IOP] is one of the major risk factors for development and progression of POAG [primary open-angle glaucoma], and its reduction is considered the only intervention proved to slow progression of the disease,” Wesam Shamseldin Shalaby, MD, of Wills Eye Hospital Glaucoma Research Center, Philadelphia, and colleagues wrote. “IOP reduction is currently achieved by topical hypotensive medications, laser therapy or incisional surgical procedures including trabeculectomy and glaucoma drainage devices.”
The researchers wrote that MIGS devices such as the iStent inject, approved by the FDA in 2018, may enable safer and more effective glaucoma treatment. It is the smallest available MIGS device, and 76% of surgeons performing MIGS procedures preferred iStent, according to the American Glaucoma Society.
Shalaby and colleagues reviewed 38 studies published between 2012 and March 2020 reporting on the second-generation iStent, as well as articles appearing in searches for “trabecular microbypass,” “micro incisional glaucoma surgery” and “MIGS” to determine safety, efficacy and cost compared with the first-generation iStent and other MIGS tools. They included retrospective and prospective studies.
Data from these studies showed that iStent with cataract surgery reduced IOP (range, 3.03 mm Hg to 9.74 mm Hg) for all glaucoma severities and across subtypes. Further, iStent inject alone showed IOP reduction (range, 7 m Hg to 13.1 mm Hg) across subtypes and with glaucoma severity including uncontrolled on one or two medications, any progression and failed trabeculectomy or filtration surgery.
Shalaby and colleagues observed that iStent inject was at least as effective as other MIGS procedures in reducing medication and IOP. Aqueous outflow facility increased with the first and second stent placements.
Moreover, there were no serious postoperative adverse events and minimal intraoperative events noted. Adverse events were comparable between iStent and iStent inject. Two studies determined iStent inject was cost-effective in IOP reduction compared with cataract surgery alone.
Shalaby and colleagues suggested future studies could supplement the current review with more information and comparisons with other trabecular MIGS.
Perspective
Back to Top
MIGS are here to stay. They play an important and evolving role in glaucoma management and bridge a distinct gap between topical medications/laser and incisional surgeries. The iStent was the first on the scene, and the more recently approved iStent inject is more efficacious.
Having said that, I’ve found the IOP lowering ability of the iStent family to be underwhelming. Our most effective MIGS, the Cypass (Alcon), was voluntarily recalled due to corneal endothelial damage. Other devices like the Hydrus (Ivantis) seem to be preferred by glaucoma specialists. Some procedures, like KDB (New World Medical) and gonioscopy-assisted transluminal trabeculotomy, don’t use implants but modify tissue. Where does that leave the venerable iStent?
Shalaby and colleagues performed an extensive review of the iStent literature. They suggest that iStent meets the five key criteria for MIGS: high safety, minimal tissue disruption, swift recovery, cost effectiveness, ab interno approach and “at least modest effectiveness.” The iStent meets these criteria but falls a bit short on effectivity.
As earlier stated, this is a dynamic and evolving area of glaucoma treatment. The iStent is safe and easy to use, but more efficacious options are available. While iStent will continue to play an important role glaucoma management, in time I suspect other procedures will further this gap.
Collapse
Read more about
Click Here to Manage Email Alerts