title: Long-term experience of patch graft failure after Ahmed Glaucoma Valve® surgery using donor dura and sclera allografts.
abstract: OBJECTIVE
  To report the long-term incidence, timing, and experience of patch graft failure (PGF) after Ahmed Glaucoma Valve (AGV) (New World Medical, Inc., Rancho Cucamonga, CA) surgery in a large consecutive case series using donor dura mater and sclera sequentially as the allograft materials.
  
  
  METHODS
  The medical records of all AGV surgeries performed from June 1994 through December 2010 were retrospectively reviewed for cases of PGF.
  
  
  RESULTS
  Patch graft failure occurred in 44 (6.3%) of the initial 695 procedures using dura and in 65 (5.8%) of the subsequent 1,121 procedures using sclera (P = .64). The time interval after AGV surgery until the occurrence of PGF was significantly longer for dura (5.8 ± 3.8 years) than for sclera (2.7 ± 1.9 years) (P < .001).
  
  
  CONCLUSIONS
  After an average of 4 years, PGF occurred in 109 (6%) of 1,816 consecutive AGV surgeries using donor dura and sclera allografts. PGF may be the most frequent long-term complication after AGV surgery.
authors.affiliation: Department of Ophthalmology, University of Cincinnati College of Medicine and Cincinnati Eye Institute, Cincinnati, Ohio, USA. zaltaah@uc.edu
authors.forename: Alan H
authors.initials: AH
authors.lastname: Zalta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004388:Dura Mater / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006084:Graft Rejection / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012189:Retrospective Studies; D012307:Risk Factors; D012590:Sclera / Q000637:transplantation*; D013997:Time Factors; D014019:Tissue Donors; D014184:Transplantation, Homologous; D055815:Young Adult