XEN gel stent for the treatment of open-angle glaucoma: real-world effectiveness and safety

The term glaucoma refers to a broad group of diseases causing characteristic optic nerve damage. Elevated intraocular pressure (IOP) does not define glaucoma but has been strongly associated with the development and progression of glaucomatous damage and is currently the only modifiable risk factor. Among new surgical procedure to reduce IOP, the XEN gel stent implantation offers sub-conjunctival filtration by the implantation of a flexible 6mm tube. In the present work we have prospectively collected data on XEN implantations performed at our site with the aim to assess the efficacy and safety of the procedure. In this research we found that a post-operative IOP below or equal to 9 mmHg, which is the theoretical pressure drop of the implant, is also predictive of long-term efficacy of the procedure. We reported and analysed two relevant complications regarding the XEN implantation. Choroidal detachment has been associated with higher patient's age and with an increased number of IOP-lowering drugs. We also reported cases where the implant appeared damaged during the follow-up and we described the clinical course. Then, comparing XEN with trabeculectomy, we found that the two procedures are comparable when the IOP success criterion is in the mid-teens but is favourable to trabeculectomy when a very low IOP target is needed.