title: Fibrovascular ingrowth as a cause of Ahmed glaucoma valve failure in children.
abstract: OBJECTIVE
  The purpose of this study is to document the presence of fibrovascular ingrowth into the Ahmed glaucoma valve (AGV) as a cause of AGV failure in the pediatric population.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Retrospective study of six children with histologically documented fibrovascular ingrowth of their AGV, with review of relevant demographic, clinical, and surgical factors.
  
  
  RESULTS
  Six patients, two males and four females, with a mean age at AGV placement of 27.5 months (range 1 to 122) were identified with AGV failure, AGV removal, and subsequent histology documenting fibrovascular ingrowth into the valve chamber. Etiology of glaucoma included: trauma, aphakia, angle-closure, aniridia, and infantile. Mean time from AGV implantation to explantation was 23 months (range 6 to 65). Mean intraocular pressure at AGV explantation was 35 mm Hg (range 27 to 48).
  
  
  CONCLUSIONS
  Fibrovascular ingrowth of both the pediatric and adult size AGV occurs in children and should be considered in the presence of AGV failure.
authors.affiliation: Dean A. McGee Eye Institute, Oklahoma City, Oklahoma, and Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Lucas
authors.initials: L
authors.lastname: Trigler
authors.forename: Alan D
authors.initials: AD
authors.lastname: Proia
authors.forename: Sharon F
authors.initials: SF
authors.lastname: Freedman
mesh_terms: D002648:Child; D002675:Child, Preschool; D020878:Device Removal; D005260:Female; D005347:Fibroblasts / Q000473:pathology*; D005355:Fibrosis; D005901:Glaucoma / Q000601:surgery; D020327:Glaucoma Drainage Implants; D006801:Humans; D007223:Infant; D007429:Intraocular Pressure; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D011475:Prosthesis Failure; D019919:Prosthesis Implantation; D012189:Retrospective Studies