Glaucoma is a group of eye conditions that damage the optic nerve, the pathway connecting the eye to the brain. This damage often occurs due to elevated pressure inside the eye, known as intraocular pressure (IOP). If left untreated, glaucoma can lead to permanent vision loss. The Xen Gel Stent is a surgical treatment option to manage elevated IOP.
The Xen Gel Stent Explained
The Xen Gel Stent is a small, flexible tube made from a biocompatible material. Its purpose is to reduce high intraocular pressure in patients with open-angle glaucoma when medications are insufficient. The stent creates a new, permanent drainage pathway for aqueous humor, the fluid inside the eye. This fluid flows from the anterior chamber into the subconjunctival space, located under the conjunctiva. The drained fluid forms a small blister, or bleb, under the conjunctiva, which is absorbed by surrounding blood vessels.
Measuring Treatment Success
Treatment success is defined by specific criteria related to intraocular pressure (IOP) control. A primary measure is a significant reduction in IOP to a predetermined target level, aiming to slow disease progression and prevent further vision loss. Common thresholds include achieving an unmedicated IOP of 12 mmHg or less, 15 mmHg or less, or 18 mmHg or less, along with a 20% reduction from baseline IOP.
Another way treatment success is measured is by a reduction in the patient’s reliance on glaucoma medications. Patients are considered to have achieved “complete success” if their IOP is controlled without the need for any medications. “Qualified success” means the IOP is controlled, but the patient still requires some medication. The avoidance of further surgical interventions due to uncontrolled IOP also contributes to the definition of long-term success.
Reported Success and Influencing Factors
Published clinical studies indicate varying success rates for the Xen Gel Stent, depending on the definition of success and follow-up duration. A meta-analysis reported an overall complete success rate ranging from 21.0% to 70.8% after two years. Another study observed a complete success rate of 26% and a qualified success rate of 48% at 24 months, with success defined as an IOP reduction of at least 20% from baseline and an IOP between 6 mmHg and 18 mmHg.
Several factors influence the success rate of the Xen Gel Stent:
- Patient-specific characteristics play a role; for example, male and older patients have shown better surgical results in some studies.
- The type and severity of glaucoma, as well as any prior eye surgeries, can also impact outcomes.
- The surgeon’s experience and technique are also considerable factors, as proper stent placement is important for long-lasting IOP control.
- Patient adherence to post-operative care, including the use of anti-scarring medications like mitomycin C, is important as excessive scarring around the stent can hinder its function.
- Combining the Xen Gel Stent implantation with cataract surgery may lead to lower success rates compared to standalone procedures.
Life After the Procedure
Following Xen Gel Stent implantation, patients can anticipate a recovery period that involves some initial blurriness, discomfort, and light sensitivity, which gradually improve over several weeks. Most patients can resume normal activities within a few days to a few weeks. Immediate post-operative care usually includes the use of prescribed steroid and antibiotic eye drops to manage inflammation and prevent infection.
Regular follow-up appointments with the ophthalmologist are important to monitor IOP and assess the stent’s function. During these visits, additional treatments like bleb needling, which involves releasing fibrotic tissue around the stent, may be performed if the IOP starts to rise. Glaucoma remains a chronic condition requiring ongoing monitoring, even after successful surgery, and some patients may still require additional interventions or medications in the long term to maintain target IOP.