title: Ahmed valve implantation in glaucoma secondary to chronic uveitis.
abstract: OBJECTIVE
  To evaluate the efficacy of Ahmed valve (AV) implantation in patients with uveitic glaucoma.
  
  
  METHODS
  In total, 18 patients (19 eyes) with glaucoma secondary to chronic uveitis, who underwent AV implantation were retrospectively reviewed. Visual acuity, intraocular pressure (IOP), and glaucoma medications at the most recent examination prior to surgery, were compared with those of last postoperative examination. The surgical success was defined as IOP less than 21 mmHg and greater than 4 mmHg without loss of light perception and visually devastating complications at the last postoperative examination. Decrease in the number of glaucoma medications was also a criterion for surgical success.
  
  
  RESULTS
  The mean follow-up period was 26+/-9.7 months. The mean preoperative and postoperative IOPs were 33.3+/-9.7 (range, 20-57) mmHg and 17.3+/-10.8 (range, 6-40) mmHg respectively (P<0.0001). The mean number of antiglaucoma medications was 3.5+/-0.8 (range, 2-5) preoperatively and 1.4+/-1.3 (range, 0-4) postoperatively (P<0.0001). Valve occlusion (five eyes, 26.3%) was the most commonly observed complication. Surgical success was achieved in 13 eyes (68.4%). The cumulative probability of success was 94.4% at 1 year and 60% at 2 years. Five eyes (26.3%) with IOP greater than 21 mmHg and one (5.3%) with corneal decompensation requiring penetrating keratoplasty were considered as failures.
  
  
  CONCLUSIONS
  The implantation of AV is an effective surgical procedure for the management of uveitic glaucoma. The inflammatory background might contribute to the occurrence of valve occlusion, which is the most common complication. Prevention of this complication is an essential factor for improving the surgical outcome.
authors.affiliation: Department of Ophthalmology, Uveitis Service, McGill University, Montréal, Canada. pinarozdal@hotmail.com
authors.forename: P C
authors.initials: PC
authors.lastname: Ozdal
authors.forename: R N G
authors.initials: RN
authors.lastname: Vianna
authors.forename: J
authors.initials: J
authors.lastname: Deschênes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage; D002648:Child; D002908:Chronic Disease; D004334:Drug Administration Schedule; D005260:Female; D005901:Glaucoma / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000009:adverse effects; D012189:Retrospective Studies; D014605:Uveitis / Q000150:complications*; D014792:Visual Acuity
chemical_list: D000959:Antihypertensive Agents