Posted by: Clemson Eye in News
BY APRIL A. MORRIS
Greenville Business Journal, September 25, 2014
Tiniest implant ever approved by FDA is saving the sight of Upstate glaucoma patients
Glaucoma – the second leading cause of blindness in the world – has been called “the silent thief of sight” because the symptoms are few until the damage is done. Detected with an eye exam, the condition has no cure but can be treated with eye drops, laser treatments or surgery.
Now a new implant is giving glaucoma patients new hope.
The iStent – the smallest implant ever approved by the U.S. Food and Drug Administration – is less invasive and reduces the taxing daily treatment régime patients normally face, said Dr. Joseph Parisi, an Upstate ophthalmologist with Clemson Eye.
Measuring one millimeter long and one-third of a millimeter high, the tiny stent opens up a channel that drains fluid from the eye and reduces pressure, Parisi said.
Glaucoma is caused when a network of tissue that drains fluid out of the space between the iris and cornea becomes blocked or drains too slowly, he said. The resulting pressure can damage the optic nerve and cause vision loss or blindness.
Parisi began implanting the stent, which gained FDA approval in 2012, several months ago and calls it a viable treatment for patients with mild to moderate glaucoma. A bonus of the implant is a marked reduction in a vexing, daily treatment régime: daily and sometimes irritating eyedrops that patients have difficulty continuing, he said.
Up to half of patients stop using the eyedrops and up to 90 percent don’t use them as directed, Parisi said. “The problem with compliance in glaucoma treatment is horrific. Laser treatments can have some effectiveness, but maybe not as much as you need.”
The stent, which resembles a snorkel with fins, is implanted during cataract surgery. Roughly 20 percent of cataract patients have glaucoma, Parisi said. The size of the stent requires complex microscopes and mirrors to make sure the device is placed correctly, he said, estimating the insertion adds roughly 15 minutes to a cataract surgery.
Patients who received the stents during clinical trials maintained the resulting drop in eye pressure for more than two years and saw the number of drops required cut by half, he said.
In addition to reducing eyedrop use, the stent procedure is less invasive than previous “gold standard” glaucoma treatments that came with a high potential complication rate, he said. A second-generation iStent is now in the works.
