New implant provides drug-free glaucoma treatment
BY KIM MULFORD May 20, 2013 12:00PM
MOORESTOWN, N.J. — Dr. Sander Cohen peered through a microscope as he managed the intricate dance between the instruments in his hands and the floor pedals he worked in his stocking feet.
Before him was the unblinking eye of his patient, an older woman whose sight had deteriorated so much that she no longer could drive legally. Cataracts clouded her vision and astigmatism blurred what she could see, problems easily corrected with a common surgical procedure and the insertion of a specially designed lens.
But the ophthalmologist was particularly interested in addressing his patient’s glaucoma, which can cause irreversible vision loss if left untreated. A number of eye diseases can cause the condition, but high eye pressure is the leading factor for the most common form of glaucoma.
Using the same tiny cut he had made to take out the cataract, Cohen inserted a 1-millimeter titanium device called an iStent, the smallest medical device the Food and Drug Administration ever approved. As Cohen nudged the micro-size device into a part of the eye called the Schlemm’s canal — a drainage channel that collects excess fluid inside the cornea on the outside edge of the iris -- his colleague, Dr. James Nachbar, marveled at the procedure.
“It’s so delicate,” said Nachbar, who soon will perform his first iStent procedure. “To me, it’s like docking a space shuttle.”
Designed to help fluid drain out of the eye, the iStent works to lower eye pressure and reduce the risk of damage to the optic nerve. Patients can’t see or feel the device once it is implanted.
“It’s new technology. She’ll be bionic,” said Cohen.
Glaucoma is a permanent condition that can cause dark patches to appear in the field of vision. Often, a patient does not experience symptoms until vision loss already has occurred. Only about half of the estimated 3 million Americans who have the condition are aware of it, according to the American Academy of Ophthalmology.
Treatments include eye drops, laser surgery and more extensive cutting surgery. The iStent is an intermediate treatment option for patients with both cataracts and mild to moderate glaucoma. Up to 75 percent of patients are able to stop taking eye drops after getting the implant, studies showed.
Dr. Iqbal Ahmed of the University of Toronto told Medscape Medical News that the decrease in eye pressure lasts as long as five years.
Medicare and many private insurance plans cover the $1,000 device, manufactured by Glaukos of Laguna Hills, Calif.
Dr. L. Jay Katz, chief of the glaucoma service at Wills Eye Institute in Philadelphia, reviewed the iStent’s initial data before the FDA approved it. The eye hospital was among the first in the nation to use the device in clinical practice.
“Because it’s so tiny, the complications with this are very, very small, and it’s relatively quick,” Katz said.
But it’s just the beginning, he added. Already, modifications to make the device better, smaller and more easily inserted are being studied in clinical trials.
“Things are moving along very quickly,” Katz said. “The technology is astounding, and I think it’s for the betterment of patients.”
Alvin B. Baxter of Lumberton, N.J., was among the first of Cohen’s patients to get the implant nearly two months ago. The retired Army veteran had problems seeing the dashboard of his car and his failing eyesight threw off his golf game.
After Cohen explained the procedure, Baxter recalled: “I told him to go for it — so far, so good.”
The procedure did not hurt, he said, and he went out to eat breakfast with his wife immediately after leaving the surgical center.
“I put the shades on,” the 77-year-old said, “and never looked back.”