The XEN® gel stent reduces intraocular pressure (IOP) in glaucoma. XEN®-45 is widely used while the newer XEN®-63 has a larger lumen that may lower IOP more. We retrospectively compared the first 15 XEN®-63 cases to 15 matched XEN®-45 controls. With a preoperative IOP of 18.1 ± 3.9 mmHg (mean ± SD) and a final IOP of 9.2 ± 4.2 mmHg, XEN®-63 implantation resulted in an IOP reduction of 48.0 ± 23.3%. Similarly, with a preoperative IOP of 18.3 ± 4.5 mmHg and a final IOP of 10.5 ± 2.3 mmHg, XEN®-45 implantation resulted in an IOP reduction of 39.5 ± 17.81%. The median follow-up period was 57 days for the XEN®-63 group and 183 days for the XEN®-45 group. 5/15 eyes of each group underwent open conjunctival bleb revision within the period of observation. Two eyes of the XEN®-63 group also had secondary glaucoma surgery. In both groups only one eye required restart of antiglaucomatous medication. XEN®-63 and XEN®-45 effectively lower IOP and medication. XEN-63 achieved lower IOP over a short follow-up. Com-plication and revision rates were similar.