Glaucoma medical treatment as a predictor of XEN45 subconjunctival gel implant hypotensive efficacy

Purpose The aim of this study was to determine the preoperative characteristics influencing hypotensive efficacy of the XEN45 gel stent in patients with open-angle glaucoma at one-year follow-up. Materials and methods This was a retrospective multicentre study. All patients who underwent XEN45 gel stent implantation between January 2017 and January 2021 were included. The main study outcome was the assessment of one-year postoperative intraocular pressure (IOP) and glaucoma medication differences according to the number and type of preoperative topical treatments or glaucoma surgery, glaucoma stage and time since diagnosis. Follow-up period was 1-year post-surgery in all cases. IOP reduction and surgery success (not requiring reoperation or pressure failures [IOP > 18 mmHg and < 20% reduction in IOP]), safety and cost savings in topical glaucoma therapy after surgery were secondarily assessed. Linear regression analysis to determine the preoperative parameters influence on 1-year postoperative results was performed. Results XEN45 gel stent was implanted in 85 patients. One-year postoperative mean IOP dropped from 20.6 +/- 4.1 to 13.7 +/- 2.8 mmHg (p < 0.0001). Likewise, mean number of topical treatments decreased from 2.05 +/- 0.9 to 0.36 +/- 0.65 (p < 0.001). Both were mainly influenced by the number of preoperative glaucoma treatments, such that for each one-glaucoma medication increase, postoperative intraocular pressure increased by 1.18 mmHg (95% CI 0.56-1.79, p < 0.0001) and number of glaucoma medications increased by 0.3 (95% CI 0.16-0.43, p < 0.001). Overall success rates (with and without supplemental glaucoma medication use) were 97.6% (95% CI 94.5-100%), 87.1% (95% CI 80.2-87.1%) and 61.2% (95% CI 51.6-72.5%) at 3, 6 months and 1 year after surgery. No sight-threatening adverse events were reported. Mean annual cost savings on medical treatment since surgery reached EUR 251.19 +/- 169. 93 euros. Conclusions One year after surgery, XEN45 gel implant significantly reduced IOP and number of topical medications with an adequate safety profile being both mainly influenced by the number of preoperative glaucoma treatments.