About once a month, Deidre St. Peter, MD, assistant professor of ophthalmology at the University of Colorado School of Medicine, performs a XEN Gel Stent surgery, implanting a tiny tube-like structure into the eye to reduce pressure and prevent vision loss associated with open-angle glaucoma.
“It’s becoming quite popular,” says St. Peter, who presented in September on the “pearls and pitfalls” of XENs at the CU Department of Ophthalmology’s 27th Annual Ophthalmology Symposium.
The small implant that became available in 2016 is inserted into the eye to help drain fluid and reduce intraocular pressure (IOP) in glaucoma patients. There isn’t a cure for the nearly 3 million Americans diagnosed with some form of glaucoma, so reducing pressure is crucial in preserving vision.
XENs and reducing pressure
Glaucoma, a leading cause of blindness around the world, is a group of diseases that progressively harms the optic nerve in the eye.
“That damage is irreversible, so once there has been damage to the optic nerve from glaucoma, we can't get that nerve tissue back,” St. Peter explains. “When we're treating glaucoma, we're not trying to reverse any type of disease. We're actually trying to prevent a disease from getting worse, and the only way we know how to do that is by lowering the pressure inside of the eyes.”
Lowering the pressure inside of the eye can help prevent further vision loss. Medication, surgery, or a tool such as the XEN Gel Stent, can help balance the fluid.
“The eyes are like a bathtub. There’s a faucet that’s constantly turned on, so fluid is flowing into the eyeball. There should be a drain that’s open so that the water flowing into the tub is balanced with water that is draining out of the tub,” St. Peter says. “With glaucoma, we try to lower the pressure in the tub, and there are a few ways to do that. We can turn down the faucet, open up the drain, clean out the drain, or poke a hole on the side of the tub to make a new drain.”
Medications can help increase outflow, while minimally invasive glaucoma surgeries, such as the XEN Gel Stent, can also aid drainage in the eye. Sometimes bigger procedures are needed when a patient needs to significantly reduce IOP.
Trabeculectomy vs. XEN Gel Stents
Traditionally, ophthalmologists might perform a trabeculectomy, a procedure in which the physician removes a part of the drainage system to allow fluid in the front part of the eye to drain. A XEN Gel Stent, by contrast, uses a tiny device — about the length of an eyelash — that acts as a tube to help guide the fluid to the outside of the eye and lower pressure. The stents can be left in the eye indefinitely.
“The XEN Gel Stents are very similar to the trabeculectomy, but avoid some of the pitfalls,” St. Peter explains. “With trabeculectomies, you can sometimes see eye pressure drop too low with fluid draining out of the eye. That can cause pain, headaches, and, in some cases, vision loss."
Reducing pressure too much is also possible with the XEN Gel Stent, but the design aims to prevent that from happening.
St. Peter says trabeculectomies are still a sound option for some patients who need to significantly lower IOP because it may lower pressure more than the XEN stent.
“It’s important to consider options with your ophthalmologist so that the treatment targets eye pressure effectively,” St. Peter says. “I’ve seen great results with the XEN Gel Stent and many patients are happy with it. It’s a procedure we should keep wanting to improve because it can help improve a patient’s overall outcome.”
