Evaluation of the Xen Implant in Glaucoma Surgery

Glaucoma is a blinding optic neuropathy that affects 60 million people around the world. Primary open-angle glaucoma is the most common etiology. The therapeutic arsenal now includes medicated hypotonic treatments, lasers and surgery. The most common glaucoma surgery in France is trabeculectomy and non-perforating deep sclerectomy. These are two filtering surgeries whose principle is to lower the intraocular pressure by creating a way of evacuation of the aqueous humor from the anterior chamber of the eye to the space sub conjunctival creating a bubble of filtration. The short-term complications with these techniques are early hypotonia and its attendant complications (choroidal detachment, maculopathy of hypotonia, haemorrhage...). In the medium term, blood pressure with deep anterior chamber, testify to a scleral flap too tight which may require suture lysis. Finally, the problems of excessive conjunctivo-tenon healing affect 25 to 30% of operated and are responsible for the majority of late blood pressure. In the longer term, the most common complication is cataracts. It can be complicated by a very serious endophthalmitis. A new minimally invasive therapeutic option has been developed that limits per and postoperative complications. In contrast to traditional techniques that have an ab externo approach, the ab interno approach of the proposed new technique involves the implantation of a collagen tube 6 mm in length and 45 μm of light called Xen® through the anterior chamber. This surgery can be performed alone or at the same time as a cataract surgery. The geometry of the Xen® implant has been studied to prevent major hypotonia. This new technique would also avoid the complications associated with conjunctival dissection, while being faster. A Xen® implant is nowadays indicated for simple surgery or combined with cataract surgery for open-angle, early-to-moderate, cataract and non-cataract glaucoma, progressive and unbalanced under local hypotonism therapy. Since June 2017, the Xen® technique is part of the routine at GhPSJ.