Alcon has announced an immediate, voluntary market withdrawal of its device used to treat some types of glaucoma, called the CyPass Micro-Stent. Alcon said its action is not related to a manufacturing or quality issue. The company's decision is based on analysis of a long-term safety study of the device.
Glaucoma is a disease that damages the eye's optic nerve. It usually happens when fluid builds up in the front part of the eye. That extra fluid increases the pressure in the eye, damaging the optic nerve. The stent creates a new path for liquid to flow out of the eye, reducing pressure in the eye.
The U.S. Food and Drug Administration approved the CyPass Micro-Stent in July 2016 for use in conjunction with cataract surgery in adult patients with mild-to-moderate primary open-angle glaucoma. Primary open-angle glaucoma is the most common type of glaucoma.
The two-year study that served as a basis for FDA approval of the stent included an evaluation of endothelial cell loss. Endothelial cells are critical to maintain visual function. That study found little difference in these cells between patients who received the stent and those who only had cataract surgery. But the company continued the study for an additional three years.
It found that after five years, patients who had received a CyPass implant experienced statistically significant endothelial cell loss.
Based on this new information, Alcon is advising surgeons to immediately stop implanting the stents. The company will tell ophthalmic surgeons how to evaluate and manage patients who already have received a stent.
"Although we are removing the product from the market now out of an abundance of caution, we intend to partner with the FDA and other regulators to explore labeling changes that would support the reintroduction of the CyPass Micro-Stent in the future," the company said in a statement.
"If you already have one of these stents in your eye, don't panic, but do talk to your ophthalmologist," said Andrew G. Iwach, MD, an ophthalmologist in San Francisco who specializes in glaucoma. "Your ophthalmologist can give you an exam right in the office to assess the risk of this potential complication. In this setting endothelial cell loss would not be expected to happen suddenly. But you may need to be monitored."
In other words, this is not an urgent situation. Not everyone who has the stent will have problems. And any potential problems may be years away for some patients.
Dr. Iwach applauded Alcon for continuing to monitor the patients in the original study even after the device was approved by the FDA. "With any innovation, there are unexpected things that can show up. The good news is they continued to monitor these first patients, detected this issue and acted immediately," he said.
Alcon is gathering a panel of medical experts to examine the current evidence. It will issue clinical recommendations for ophthalmologists who are treating patients who have CyPass stents.