Glaucoma Drainage Device and Endothelial Cell Loss Compare Trial

This study is comparing two placements of a tube used in glaucoma drainage devices — a tiny implant that helps drain fluid from the eye to lower pressure and prevent vision loss in patients with uncontrolled glaucoma. The trial compares placing the tube in the anterior chamber (front part of the eye) versus the ciliary sulcus (behind the iris), and measures how each affects the corneal endothelial cells (a delicate layer of cells on the surface of the cornea). **You may be eligible if:** - You are 18 or older - You have medically uncontrolled glaucoma requiring a glaucoma drainage device (tube implant), with or without simultaneous cataract surgery - You are a candidate for ciliary sulcus tube placement **You may NOT be eligible if:** - You have a pre-existing corneal disease or previous corneal transplant - You have had a previous glaucoma drainage device, Xen Gel Stent, or Preserflo MicroShunt removed less than 6 months ago - You currently have any of those implants in place - You have had trabeculectomy or minimally invasive glaucoma surgery within the past 6 months - Your glaucoma requires surgery combined with another eye procedure (like a corneal transplant or retinal surgery) - You have very poor vision in the study eye or the other eye - You have nanophthalmos, uncontrolled uveitis, silicone oil, or other special conditions Talk to your doctor to see if this trial is right for you.