■ A review of 38 studies evaluating the second-generation Glaukos iStent inject reveal it to be a safe and effective procedure for treating open-angle glaucoma (OAG) as a standalone procedure or combined with cataract surgery. According to Wesam Shamseldin Shalaby, MD, and colleagues writing in the Journal of Cataract and Refractive Surgery, the device appears to be superior to the first-generation iStent.
The investigators evaluated prospective and retrospective studies that reported on the safety, efficacy, and cost of iStent inject vs the first-generation iStent and other minimally invasive glaucoma surgery (MIGS) tools. Data revealed that iStent with cataract surgery reduced IOP from 3.03 mmHg to 9.74 mmHg for all glaucoma severities and across subtypes. Implanting the iStent inject alone was associated with an IOP reduction ranging from 7 mmHg to 13.1 mmHg across subtypes and with glaucoma severity including uncontrolled on 1 or 2 medications, any progression, and failed trabeculectomy or filtration surgery.
Shalaby et al noted 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.
“The iStent inject embodies the 5 key criteria of MIGS procedures,” the researchers wrote, “including high safety, minimal tissue disruption, swift recovery, at least modest effectiveness, and ab interno approach.” As evidence of this, a recent survey of the American Glaucoma Society found that more than three-quarters of surgeons who perform MIGS procedures preferred to use the iStent.
The iStent inject is the smallest of the currently available MIGS devices, minimizing tissue disruption within the angle. Preservation of ocular tissue may potentially allow for future more invasive, angle-based procedures if needed, the authors wrote.
The safety of iStent inject implantation is about the same as cataract surgery alone with adverse events being generally uncommon, mild, and readily corrected. “This positive benefit-to-risk assessment customarily is considered applicable to patients with more mild or moderate glaucoma that does not yet warrant the risks of filtering surgery,” the investigators wrote. The iStent inject’s indications have been expanded to severe and recurrent forms of glaucoma. Shalaby et al wrote that future studies should add more information and comparisons to other trabecular MIGS.