title: Clinical outcomes of Ahmed glaucoma valve implantation using tube ligation and removable external stents.
abstract: OBJECTIVE
  To investigate the immediate and long-term outcomes of Ahmed glaucoma valve (AGV) implantation with silicone tube ligation and removable external stents.
  
  
  METHODS
  This retrospective non-comparative study investigated the outcomes of AGV implantation with silicone tube ligation and removable external stents in 95 eyes (90 patients) with at least 12 months of postoperative follow-up. Qualified success was defined as an intraocular pressure (IOP) of <or=21 mmHg and >or=6 mmHg regardless of anti-glaucoma medication. Those who required additional glaucoma surgery, implant removal or who had phthisis bulbi were considered failures. Hypotony was defined as an IOP of <6 mmHg.
  
  
  RESULTS
  Mean IOP reduced from 37.1+/-9.7 mmHg preoperatively to 15.2+/-5.6 mmHg at 12 months postoperatively (p<0.001). Qualified success was achieved in 84.2% at 1 year. Hypotony with an IOP of <6 mmHg was seen in 8.4% and an IOP of <5 mmHg in 3.2% on the first postoperative day. No case of hypotony required surgical intervention. Suprachoroidal hemorrhage did not occur in this study. When stents were removed on the first postoperative day because of an insufficient IOP decrease, the mean IOP decreased significantly from 42.0 mmHg to 14.1 mmHg (p<0.001) after 1 hour. The most common complication was hyphema, which occurred in 17.9%.
  
  
  CONCLUSIONS
  Hypotony-related early complications requiring surgical intervention were reduced by ligation and external stents in the tube. In addition, early postoperative high IOPs were managed by removing external stents. The described method can prevent postoperative hypotony after AGV implantation and showed long-term success rates comparable to those reported previously.
authors: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors: Jong Joo
authors: JJ
authors: Lee
authors: Ki Ho
authors: KH
authors: Park
authors: Dong Myung
authors: DM
authors: Kim
authors: Tae Woo
authors: TW
authors: Kim
mesh_terms: D004867:Equipment Design; D005260:Female; D018463:Filtering Surgery / Q000295:instrumentation*; D005500:Follow-Up Studies; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure; D008026:Ligation / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012826:Silicone Elastomers; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D012826:Silicone Elastomers