Same Quadrant Trabeculectomy after Failed Ab Externo Open Conjunctiva XEN Stent Implantation

Purpose: Conjunctival incisional surgery is a known risk factor for trabeculectomy failure. The occurrence of avascular bleb following failed ab interno XEN stent implantation has been documented in patients undergoing trabeculectomy with mitomycin C (MMC). However, reports on same quadrant trabeculectomy with MMC after failed ab externo open conjunctiva XEN stent implantation are scarce. This study sought to document the 1-year clinical outcomes and bleb morphology following this procedure.Case summary: This retrospective study reviewed the medical records of 4 eyes from 4 patients who received trabeculectomy with MMC in the same quadrant following ab externo open conjunctiva XEN stent implantation failure. At 1 year after trabeculectomy, the intraocular pressure was successfully controlled without glaucoma medication, and no visual field progression was observed. Anterior segment tomography indicated that the blebs were elevated and broad, with a suprascleral fluid-filled space evident in all eyes. There were no instances of prolonged hypotony or bleb leakage one year after the trabeculectomy, although an avascular bleb was observed in one eye.Conclusions: Performing trabeculectomy with MMC in the same quadrant appears to be an effective method for reducing IOP after the failure of ab externo open conjunctiva XEN stent implantation.