Abstract
Purpose :
To evaluate the safety and efficacy of Xen 45 Gel stent (Xen, Allergan, Dublin, Ireland) in eyes that have failed prior surgical intervention, compared to traditional glaucoma drainage device (GDD) or cyclophotocoagulation (CPC). Since this population has low expected success rates with any additional surgery, it is vital to compare to standard of care surgical options.
Methods :
This is a retrospective, single-site, case-control study of ab externo transconjunctival Xen in eyes that have previously undergone trabeculectomy and/or GDD surgery. Postoperative data was collected for 18 months. Failure was defined as: 1) no light perception, 2) additional glaucoma surgery required, or 3) intraocular pressure (IOP) of < 6 mmHg after 6 weeks postoperatively.
Results :
Eighteen (18) Xen eyes and 36 control eyes matched on both glaucoma type and previous glaucoma surgeries were included. 72% had primary open angle glaucoma, 11% uveitic glaucoma, 6% primary angle closure, 6% pseudoexfoliation and 6% pigmentary glaucoma. 56% of eyes in each group had prior trabeculectomy, 28% of Xen and 31% of control eyes had prior GDD, and 17% of Xen and 14% of control eyes had both. Baseline medicated IOP was lower in the Xen group (21.8 ± 7.2) compared to controls (27.5 ± 9.4, P=0.027). The cumulative failure rate at 1 year was 17% and 20% for Xen and control respectively (P=0.32). All eyes failed by requiring additional surgery, except a control eye which failed due to loss of light perception. The mean survival time was 13.7 (±1.6) months and 11.4 (±0.6) months for Xen and control, respectively. Most Xen failures occurred within the first 6 months. There was no difference in complication rates between groups (P=0.21). When censored for additional glaucoma procedures, there were no differences at post-op month 6 and year 1 in IOP, change of IOP from baseline, number of IOP lowering medications, or number of medications reduced from baseline.
Conclusions :
Xen provides a reasonable alternative to traditional surgery in patients that have previously undergone filtering surgery or GDD. But care must be taken to monitor patients closely in the perioperative period as failures occur early. Those devices that were successful beyond 6 months had noninferior IOP reduction compared to GDD and CPC.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.