I. Paul Singh, MD
The proliferation of technology in glaucoma continues with the recent FDA clearance of iStent infinite for use as a stand-alone procedure to reduce elevated IOP in patients with primary open-angle glaucoma uncontrolled by prior medical and surgical therapy. The iStent infinite includes three heparin-coated titanium stents preloaded into an auto-injection system that allows the surgeon to inject stents into the canal across a span of up to approximately 6 clock hours. The iStent infinite has a similar mechanism of action to the two-stent iStent inject W trabecular micro-bypass system, which is currently approved for patients with mild to moderate primary open-angle glaucoma undergoing concomitant cataract surgery.
In the U.S., up until now, we have not had an approved stand-alone trabecular micro-bypass stent option, let alone for a more refractory population of patients. As an investigator in the FDA trial, I have had experience with the iStent infinite device and found the procedure to be consistent with our experience using the FDA-approved iStent inject W, being effective, intuitive and safe. The loading system is slightly redesigned and allows for unlimited “clicks” for deploying the three stents. My clinical experience and data from the iStent infinite trial demonstrate the benefits of “re-engaging” the conventional pathway in this more advanced population of patients. This reaffirms the power of multiple 80-µm stents; in fact, 76% of subjects achieved a 20% reduction in modified diurnal IOP (53% of subjects achieved 30% or greater reduction in mean diurnal IOP) at month 12 on the same or fewer medication classes and without significant safety findings, with no explants, infections, device-related interventions or hypotony reported through 12 months.
This is a pivotal moment in the continuum of glaucoma care. With this stand-alone, bleb-free, ab interno technology addressing the conventional pathway, I do believe even more surgeons (and non-glaucoma specialists as well) will feel comfortable offering a surgical option to a refractory/advanced population of patients. At the end of the day, the goal remains the same: protect our patients from losing vision in the safest way possible.
I. Paul Singh, MD
Healio/OSN Board Member
Disclosures: Singh reports being a speaker for and consultant to Glaukos.