What is the most appropriate next step for a patient experiencing prolonged hypotony following Ahmed glaucoma valve implantation and unsuccessful medical management?  

To reduce aqueous flow through the tube, a less invasive approach involves occluding the tube lumen using a 2-0 or 3-0 Prolene suture via an ab interno technique. For complete occlusion, a Supramid suture may be used instead of Prolene. The ab interno approach minimizes conjunctival disruption. Alte...