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Doctor develops new glaucoma treatment

Ophthalmologist Arnold Prywes’ tiny revolution — Xen Gel Stent, a miniscule stent that promises to transform glaucoma treatment — finally comes into full view.

When Arnold Prywes, MD, chief of the glaucoma service at Northwell Health, first dreamed up an idea for a device to save the vision of people with glaucoma, he knew it could be a game-changer. But he could never have guessed a quarter century would elapse before he would see the device he imagined approved and in use in our area.

That device, the Xen Gel Stent, is both tiny - it's a tube about 6mm long, and 150 microns wide (the width of a human hair) - and mighty, with the power to make glaucoma treatment far less invasive than the typical surgical intervention. Last year, Dr. Prywes performed the procedure on a glaucoma patient at Syosset Hospital.

Dr. Prywes applied for a patent on his invention in 1991, then waited eight years for the U.S. Patent Office to grant it. Patent in hand, he began a search for a company willing and able to manufacture the device. "I went to just about every company involved in glaucoma treatment, and no one was interested," he says. Finally, in 2006, he got a call from a company in Georgia called the Innovation Factory. "They were in the market for intellectual property, for ideas that presented solutions to significant problems." He sold them the patent and they formed a separate company named AqueSys, Inc., to manufacture the stent. After burning through millions of dollars and many prototypes, the Xen Gel Stent was born.

But that wasn't the final hurdle. Next came clinical testing and Food and Drug Administration (FDA) approval, which wasn't granted until late 2016. (The stent was approved for use in Canada in 2015 and Europe in 2014.) Approval is one thing - cost is quite another. The device itself and the surgeon and hospital fees put the Xen Gel out of reach for many patients without coverage by insurance companies.

The best news? That final roadblock has just been cleared: As of March of this year, Medicare will pay for the procedure in New York.

A better way becomes clear

Though there are topical medications and laser procedures to treat glaucoma, surgery is the ultimate option once meds stop working, says Dr. Prywes. The standard procedure is a trabeculectomy - a delicate, invasive surgery that commonly requires a skilled glaucoma specialist to perform. Once the procedure is done, the wound must be sutured closed and drugs administered to keep scar tissue from forming.

Other procedures involve placing a shunt, but that, too, is a tricky operation and can lead to other problems, like double vision. Surgical solutions to glaucoma, says Dr. Prywes, "involve a lot of skill, a lot of time and intensive post-operative care. Usually they are successful In 50 to 70 percent of patients."

By contrast, the procedure to place the Xen Gel Stent takes 10 minutes, requires no suturing or general anesthesia and is straightforward enough to be mastered by comprehensive ophthalmologists. Patients also avoid post-operative problems like a reaction to anesthesia.

Dr. Prywes is now, at long last, realizing his vision to perform the procedure to save vision. On a 2014 trip to the Dominican Republic to perform the procedure and train other physicians in its use, he was moved nearly to tears to witness his original idea treating glaucoma in the way he imagined: simply, cleanly and successfully. "We operated on people and, when we came back the next day, it was like they'd never had surgery," he says.

In the meantime, AqueSys, Inc., the company that manufactured the stent, was bought by pharma giant Allergan, Inc. They allowed his original patent, which had been active for 17 years, to expire. "That means I don't get any royalties," he laughs. "But luckily I haven't given up my day job. And I never did this to make money. I did it because I perceived we could do something better, and we have."

Picture a balloon: Understanding glaucoma

To grasp how revolutionary the Xen Gel Stent is, you first have to understand glaucoma. And to do that, it's helpful to think of the eye as a balloon. Imagine, explains Dr. Prywes, a balloon being blown up. Pressure from the air inside the balloon prevents it from collapsing in on itself. Keep adding too much air without any escape valve, and…well, you get it. "Inside your eye, fluid is made and is also allowed to drain to the outside, a balance that keeps the eye physiologically intact."

In glaucoma, which affects about three million people in the United States, that fluid balance is out of whack. As a result, intraocular (inner eye) pressure builds. Over time, this damages the optic nerve, which brings visual information to the brain for processing. Untreated, glaucoma can lead to blindness. But now patients can look into a new treatment, thanks to Dr. Prywes.

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