Implant Associated with Low Reduction in Endothelial Cell Density

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When combined with phacoemulsification, the reduction in ECD seen with the device was similar to phacoemulsification alone.

The XEN® implant (Allergan) is associated with a low reduction of endothelial cell density (ECD), according to a study published in Glaucoma. They found the reduction was similar to that of phacoemulsification alone.

This multicenter, prospective, observational study examined patients enrolled in the Italian XEN Glaucoma Treatment Registry. Patients’ complete endothelial cell count data were collected at baseline and 6 months after implantation. Included in the study were 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 =.0004, P <.0001, and P <.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 <.0001) and in the phaco-solo group (mean difference=7.4%; 95% CI: 5.7%-9.1%, P <.0001). ECD reduction was similar in XEN+phaco and phacosolo groups (P =.9). ECD reduction was significantly greater in the XEN+phaco (mean difference=169±306, P =.021) and in the phaco-solo (mean difference=192±302, P =.0022) groups than in the XEN-solo group.

Investigators note some limitations to the study, including that it might be subject to bias and confounding, the variability in measuring ECD via specular microscopy, data from the group of patients who underwent the phaco-solo surgery was retrospective and not part of the XEN-GTR, and that data was limited to 6 months.

“Although we observed a significant corneal endothelial cell loss in the XEN-solo group, such a loss was significantly lower than that observed in both XEN+phaco and phaco-solo groups,” the researchers explain.

Disclosure: This research was supported by Allergan plc. Some of the study’s authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Oddone F, Roberti G, Posarelli C, et al. Endothelial cell density after xen implant surgery: short-term data from the Italian XEN Glaucoma Treatment Registry (XEN-GTR). J Glaucoma. 2021;30(7):559-565. doi:10.1097/IJG.0000000000001840.