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 reduction. In fact, when combined with phacoemulsification, the reduction of the endothelial cell density was similar to that expected after phacoemulsification alone.PURPOSE: To assess the impact of XEN implant, either alone or in combination with phacoemulsification, on the endothelial cell density (ECD).METHODS: Multicenter, prospective, observational study conducted on consecutive open-angle glaucoma (OAG) 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 end-point was the mean percentage change in ECD between baseline and the month-6.RESULTS: The study included 108 OAG eyes (68 in the XEN-solo and 40 eyes in the XEN+Phaco groups) and 60 control eyes (Phaco-solo group). As compared to 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% to 7.3%, P<0.0001) and in the Phaco-solo group (mean difference 7.4%; 95% CI: 5.7% to 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.