Rapid Corneal Endothelial Cell Loss After PreserFlo MicroShunt Surgery: A Case Report

We describe a rare case of rapid endothelial cell loss after PreserFlo MicroShunt (PMS) surgery, necessitating tube removal and conversion to trabeculectomy. An 85-year-old female patient with advanced bilateral primary open-angle glaucoma underwent PMS surgery in the left eye. The surgery was uneventful, and the initial postoperative course was stable, with intraocular pressure (IOP) maintained between 6 mmHg and 14 mmHg without glaucoma medication. However, despite stable IOP control, corneal endothelial cell density (CECD) declined rapidly postoperatively, decreasing from 2075 cells/mm² preoperatively to 1069 cells/mm² within 11 months. Given the progressive endothelial cell loss, PMS removal and conversion to trabeculectomy were performed in the same quadrant. Following trabeculectomy, the patient initially experienced excessive filtration, which led to hypotensive maculopathy and severe choroidal detachment. This was successfully managed with transconjunctival sutures. After stabilization, IOP remained at 8 mmHg six months postoperatively. Importantly, the rapid decline in CECD ceased following PMS removal, with CECD measuring 1038 cells/mm² six months after trabeculectomy. This case highlights the potential risk of rapid endothelial cell loss after PMS surgery and emphasizes the importance of close monitoring of endothelial cells. PMS removal may be necessary in cases of progressive CECD loss to prevent further corneal decompensation.