Endothelial Cell Density After XEN Implant Surgery: Short-term Data From the Italian XEN Glaucoma Treatment Registry (XEN-GTR)

Precis: XEN implant was associated with low endothelial cell density (ECD) reduction. In fact, when combined with phacoemulsification, the reduction in ECD was similar to that expected after phacoemulsification alone. Purpose: The purpose of this study was to assess the impact of XEN implant, either alone or in combination with phacoemulsification, on ECD. Methods: Multicenter, prospective, observational study conducted on consecutive open-angle glaucoma patients, who were enrolled in the Italian XEN Glaucoma Treatment Registry and have complete endothelial cell count data at baseline and at 6 months after implantation. The primary endpoint was the mean percentage change in ECD between baseline and month 6. Results: The study included 108 open-angle glaucoma eyes (68 in the XEN-solo and 40 eyes in the XEN+phaco groups) and 60 control eyes (phaco-solo group). As compared with baseline, mean (95% confidence interval, CI) ECD reduction was -5.6% (-7.0% to -4.9%), -11.3% (-13.8% to -10.9%), and -13.0% (14.8% to -11.8%) in the XEN-solo, XEN+phaco, and phaco-solo groups, respectively (P=0.0004, <0.0001, and <0.0001, respectively). As compared with the XEN-solo group, the ECD reduction was significantly greater in the XEN+phaco group (mean difference=5.7%; 95% CI: 4.1%-7.3%, P<0.0001) and in the phaco-solo group (mean difference=7.4%; 95% CI: 5.7%-9.1%, P<0.0001). ECD reduction was similar in XEN+phaco and phaco-solo groups (P=0.9). In absolute terms, ECD reduction was significantly greater in the XEN+phaco (mean difference=169 +/- 306, P=0.021) and in the phaco-solo (mean difference=192 +/- 302, P=0.0022) groups than in the XEN-solo group. Conclusions: The mean ECD reduction 6 months after XEN implantation was low. The ECD reduction in the XEN+phaco group was larger than in the XEN-solo group but was similar to that observed in the phaco-solo group.