Evaluation of the Impact of the XEN® Implant on Endothelial Cell Density, 3 Years After Surgery

Glaucoma is a blinding optic neuropathy affecting 80 million people worldwide, with primary open-angle glaucoma being the most common etiology. Today, the therapeutic arsenal includes drug-based hypotonizing treatments, lasers and surgery. In France, the most common surgical techniques are trabeculectomy and deep non-perforating sclerectomy (SPNP). The principle behind these filtering techniques is to lower intraocular pressure (IOP) by creating an escape route for aqueous humor from the anterior chamber (AC) of the eye into the subconjunctival space, creating a filtration bubble (FB). A new minimally invasive treatment option has been developed to limit intra- and post-operative complications. This new technique is based on an ab interno approach, with implantation through the anterior chamber of a 6mm-long, 45µm-lumen collagen tube called XEN®. As a result, there is no dissection of the conjunctivotenone planes, as is the case in traditional surgery. Since June 2017, surgeons have been able to use the XEN® technique in the ophthalmology department at GHPSJ. Today, no study has yet assessed endothelial cell loss more than 2 years after this surgery. Indeed, the presence of an anterior chamber device of any type can be associated with endothelial cell loss, which increases over time well after the surgical procedure, and may require removal of the device several years after surgery. Recent studies have investigated peripheral endothelial cell loss with other drainage systems. They show a significant decrease in peripheral endothelial cell density in relation to the implant placed in the anterior chamber. The aim of this study is to evaluate central and peripheral endothelial cell density in the long term after XEN® placement. At the visit more than 3 years after XEN® implant placement, IOP and pachymetry measurements were taken, along with a measurement of peripheral and central endothelial cell density. Corneal peripheral endothelial cell density is measured on