An iStent Infinite Implant Fights Glaucoma in a New Way

When most of us hear the word “stent,” we think of a device implanted during heart surgery to keep an artery open and blood flowing smoothly. Yet eye surgeons have been using tiny stents for years, relieving pressure on the optic nerves of glaucoma patients.

iStent Infinite for glaucoma

The drawback has been that, until now, the FDA and insurance companies only approved this procedure during cataract surgery. Glaukos, a company that has produced stents for a long time, has come up with the first FDA-approved, micro-invasive, stand-alone implant that doesn’t have to be linked to cataract removal. It’s called iStent Infinite. (Insurance companies are still figuring out how to handle it.)

Who Benefits from iStent Infinite?

It’s designed for adults with mild to moderate primary open-angle glaucoma, people who have not gotten relief from medication and/or surgical procedures that drain off the fluid known as aqueous humor.

Glaucoma is a group of diseases, usually caused when fluid buildup puts pressure on the optic nerve. The most common kind, primary open-angle glaucoma (“primary” means it’s not the secondary result of another medical condition), affects about three million Americans. It moves slowly, often imperceptibly, which is why annual eye exams matter so much. Closed-angle glaucoma affects a patient much faster and shows up in fewer than 10 percent of cases.

Damage to the optic nerve can cause loss of vision and even blindness if left untreated. Doctors usually address excess pressure first with drops. If necessary, they move on to laser treatment to open the channels where fluid flows out.

They may also resort to the gold standard for glaucoma surgery, a trabeculectomy, which creates a drainage pathway. In this surgery, the doctor creates a flap in the sclera (white part of the eye) underneath the upper eyelid. This comes with its own complications and is reserved for severe cases, whereas stents treat mild to moderate glaucoma.

Stents and Cataracts

Glaucoma patients and cataract patients both tend to be older. Traditionally, as lenses thicken with age and become cataracts, a surgeon must remove and replace them with artificial lenses. To minimize the risk of infection, surgeons install stents in glaucoma patients at the same time.

The procedure takes only a couple of extra minutes. Using a microscope to ensure accuracy, the doctor aims the insertion tube at Schlemm’s canal, a channel that carries fluid away from the eye but gets blocked during glaucoma. A trigger inserts stents into that canal, re-opening it. The stents have flanged tips that keep them in place if properly inserted, and they remain permanently in the eye. They’re made of a metal alloy but are too small to cause problems in an MRI or airport metal detector.

Doctors don’t use stents for closed-angle glaucoma. With this type, scar tissue, an overlarge cataract, or new blood vessels block the view of the drain. If you can’t see the drain, you don’t want to guess where a stent ought to go.

How Is iStent Infinite Different?

First, it comes loaded with three stents, rather than the usual two. As the name implies, the surgeon has unlimited opportunities to position the stents correctly. Other stents allow only five tries before you have to get a whole new device. Most crucially, the FDA approved it as a stand-alone procedure for people who develop glaucoma after cataract surgery.

Such patients used to undergo a trabeculectomy or a rarer surgery that prevents the body from producing so much aqueous humor. Those may eventually be necessary if the condition worsens. But most people now have an option in iStent Infinite that’s not as invasive, easier to install and leads to a shorter and less problematic recovery.

To schedule a consultation at Horizon Eye Care, call 704-365-0555 Monday-Thursday, 8 a.m. to 5 p.m., or Friday, 8 a.m. to 3 p.m. The optical department closes on Fridays at 2:30 p.m.

Randall N. Stein, MD

Medical & Surgical Management of Glaucoma, Minimally Invasive Glaucoma Surgery, Cataract Surgery, General Ophthalmology

Dr. Stein is an accomplished ophthalmologist. He specializes in medical and surgical management of glaucoma, including minimally invasive glaucoma surgery, cataract surgery and laser-assisted cataract surgery. He also practices general ophthalmology.

Locations: HuntersvilleMallard Creek, Mooresville