title: The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma II: longer-term outcomes from a single surgeon.
abstract: OBJECTIVE
  To analyze the longer-term surgical outcomes of Ahmed and Baerveldt shunt implants in the treatment of refractory glaucoma.
  
  
  METHODS
  Retrospective, nonrandomized, comparative trial.
  
  
  METHODS
  Consecutive patients who underwent glaucoma shunt implantation (70 Baerveldt, 48 Ahmed) by a single surgeon.
  
  
  METHODS
  Follow-up retrospective analysis of 118 consecutive cases of refractory glaucoma that required placement of either Ahmed or Baerveldt shunt implants for intraocular pressure (IOP) control. The longer term clinical course (survival curve analysis up to 48 months) was reviewed.
  
  
  METHODS
  The primary outcome measure was surgical success (6 mmHg < or = IOP < or = 21 mmHg without additional glaucoma surgery or devastating complication). Secondary outcome measures included mean IOP and number of medications used at the following postoperative visits: day 1, 1 week, 1 month, 3 months, 6 months, and every 6 months thereafter (up to 48 months). In unsuccessful cases, the median time to failure was determined.
  
  
  RESULTS
  No significant differences in success rates were noted at 1, 2, 3, or 4 years after surgery, with 4-year success rates of 62% for the Ahmed group and 64% for the Baerveldt group (P = 0.843). Mean IOPs were comparable from 1 to 48 months (P>0.05). However, patients in the Ahmed group required more glaucoma medications at 18, 24, 30, and 36 months (P<0.05). The median times to failure were 3.2 months in the Baerveldt group, compared with 15.0 months in the Ahmed group (P = 0.009).
  
  
  CONCLUSIONS
  No differences were observed in longer term survival rates and IOP profiles between Ahmed and Baerveldt shunt implants up to 48 months following surgery. Patients in the Baerveldt group were more likely to develop early postoperative hypotony-related complications and failure, whereas patients undergoing Ahmed implants were more likely to be on additional glaucoma medications (starting at 18 months postsurgery) and develop later onset failure.
authors.affiliation: Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA. jct2002@columbia.edu
authors.forename: James C
authors.initials: JC
authors.lastname: Tsai
authors.forename: Cameron C
authors.initials: CC
authors.lastname: Johnson
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kammer
authors.forename: Mary S
authors.initials: MS
authors.lastname: Dietrich
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents