Complete success rate not as high as expected with gel stent implant for glaucoma

Key Takeaways

• While the Xen 45 gel stent implant showed beneficial long-term outcomes for the treatment of open-angle glaucoma, a substantial proportion of patients needed follow-up procedures, according to a real-world retrospective analysis of data from an observational registry.
• The study also showed worse outcomes with Xen 45 gel stent implantation combined with cataract surgery, suggesting that combination surgery should be avoided.

The 6-mm-long Xen 45 stent, a microtube made of gelatin, treats glaucoma by draining fluid from the inside of the eye, thus relieving pressure. Initial trials for the Xen 45 gel stent implant showed beneficial outcomes, but they were not randomized, so it is important to gather real-world data on the stent, says Mitchell Lawlor, PhD, of Sydney Eye Hospital and the Save Sight Institute in Sydney, co-author of a study in the British Journal of Ophthalmology looking at real-world outcomes of the stent. 

For the study, Lawlor and colleagues identified a baseline cohort of 638 eyes with glaucoma or ocular hypertension among adult patients from the international Fight Glaucoma Blindness registry who underwent surgery to implant a Xen 45 gel stent. They then looked at outcomes two years after implantation of the stent. 

The researchers found that while the Xen 45 gel stent implant showed beneficial long-term outcomes for the treatment of open-angle glaucoma, a substantial proportion of patients needed follow-up operations or bleb needling, a procedure to reopen the stent. At 24 months, the rate of complete success — defined as an intraocular pressure (IOP) reduction ≥20% from preoperative and an IOP ≤18 mm Hg and ≥6 mm Hg with no secondary procedure at 2 years and without IOP-lowering medications — was 26%, while the rate of qualified success — defined similarly, but allowing the use of IOP-lowering medications — was 48%. A secondary procedure was needed in 18% of patients, and bleb needling was performed in 28.4%. “The success rates of surgery were probably not as high as we had expected,” Lawlor told MedPage Today.

Of note, the study showed worse outcomes with Xen 45 gel stent implantation combined with cataract surgery. Complete success and qualified success rates were higher in the Xen 45-alone group (33% and 52%, respectively) compared with the combined cataract surgery group (16% and 42%, respectively). “There may be occasions where it is necessary to combine surgery, but clinicians should be aware that the probability of success is significantly reduced,” Lawlor said.

Edited by Miriam Kaplan, PhD

Source: Randy Dotinga, MedPage Today, May 30, 2024; see source article