title: Ahmed valve surgery for refractory pediatric glaucoma: a report of 52 eyes.
abstract: OBJECTIVE
  To describe the results of Ahmed valve surgery for refractory pediatric glaucoma.
  
  
  METHODS
  We performed a retrospective review of patients younger than 18 years of age who had Ahmed valve surgery from November 1994 to January 2003. Success was defined as a reduction of the intraocular pressure (IOP) to 22 mm Hg or lower with or without medications at the last two follow-up visits, no additional glaucoma surgery, and no visually significant complications.
  
  
  RESULTS
  There were 52 eyes of 41 patients. The two most common diagnoses were congenital glaucoma (38.5%) and aphakic glaucoma (36.5%). The mean number of glaucoma surgeries before Ahmed valve implantation was 1.7 +/- 1.7. The mean age at the time of implantation was 4.9 +/- 6.5 years. The mean IOP decreased from 38.1 +/- 6.4 mm Hg to 20.7 +/- 8.2 mm Hg at last follow-up. The final visual acuity was improved or within one Snellen line in 81.5% of the eyes. Cumulative probabilities of success were 85.1%, 63.2%, 51.7%, and 41.8% at 1, 2, 3, and 4 years, respectively. The mean postoperative follow-up period or time to failure for all patients was 2.2 +/- 1.8 years (range, 3 months to 7.5 years).
  
  
  CONCLUSIONS
  The Ahmed valve was found to be useful in the management of refractory pediatric glaucoma. Although our success rates were similar to those observed in adults, the rates of certain post-operative complications were different.
authors.affiliation: Harvard Medical School, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Glaucoma Service, 243 Charles Street, Boston, MA 02114, USA.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Chen
authors.forename: Lini S
authors.initials: LS
authors.lastname: Bhatia
authors.forename: David S
authors.initials: DS
authors.lastname: Walton
mesh_terms: D000293:Adolescent; D001036:Aphakia, Postcataract / Q000150:complications; D002648:Child; D002675:Child, Preschool; D005260:Female; D005901:Glaucoma / Q000151:congenital / Q000209:etiology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007223:Infant; D007429:Intraocular Pressure; D008297:Male; D019919:Prosthesis Implantation / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity