A Case of Corneal Endothelial Cell Loss After PreserFlo MicroShunt Implantation Requiring Device Removal and Ahmed Glaucoma Valve Implantation With Tube Insertion Into the Vitreous Cavity

We report a case of progressive endothelial cell loss (ECL) following PreserFlo MicroShunt (PMS) (Santen Pharmaceutical, Osaka, Japan) implantation, which was successfully managed by PMS removal and the pars plana placement of Ahmed glaucoma valve (AGV) implantation. An 82-year-old man with primary open-angle glaucoma underwent PMS implantation combined with cataract surgery. Preoperative endothelial cell density (ECD) was 2,148 cells/mm², and intraocular pressure (IOP) was 21 mmHg despite five topical IOP-lowering medications. One week postoperatively, the IOP normalized to 11 mmHg without medication, but the ECD decreased to 1,400 cells/mm². Over the following 12 months, the ECD progressively declined to 880 cells/mm². PMS removal and AGV implantation, with tube insertion into the vitreous cavity, were performed to prevent further ECL and maintain IOP control. After the second surgery, IOP stabilized between 10 and 14 mmHg with topical treatment, including ripasudil, and ECD remained stable at approximately 1,200 cells/mm². This case demonstrates the potential for significant and progressive ECL following PMS implantation and highlights that timely intervention with PMS removal and AGV implantation with tube insertion into the vitreous cavity can effectively stabilize ECD and achieve adequate IOP control, emphasizing the importance of close postoperative monitoring and the prompt management of complications.