We herein describe possible intraluminal obstruction because of a hyperreflective material found in anterior segment optical coherence tomography (AS-OCT) in 16 of 46 cases with XEN45 gel stent. This is a retrospective case series of 46 eyes of 39 patients with noncomplicated XEN45 gel stent surgery, analyzed with AS-OCT and slit-lamp photography after at least 6 postoperative months. Possible luminal obstruction in the subconjunctival segment of the implant was observed in 16 eyes of 15 patients, characterized by hyperreflective material on AS-OCT, which was not visible in slit-lamp photography. This was found in 15 eyes following combined procedures and in 1 eye following XEN45 alone. None showed signs of filtering bleb on AS-OCT or slit-lamp photography. In 1 case, the discontinuity between the hyperreflective material and subconjunctival opening of the implant tube was evidenced, and in another case, a focal deposit in the intracameral end of the implant was seen. We have successfully described the lumen implant deposit of material as a possible cause of late failure of the implant. AS-OCT allows the identification of such cases and may be useful to plan further postoperative interventions for better patient outcomes.