title: Rates of visual field loss before and after trabeculectomy.
abstract: OBJECTIVE
  To compare the rates of change in the visual field (VF) in patients with glaucoma before and after trabeculectomy.
  
  
  METHODS
  Of 52 eyes of 52 patients with different types of chronic glaucoma who underwent first trabeculectomy were evaluated retrospectively. Pre- and postoperative-automated visual fields measured by the same technique were compared to detect differences in rates of change. Rates of VF loss before and after trabeculectomy were calculated using mean deviation (MD). Linear mixed models were used to compare the rates of change in the VF before and after trabeculectomy.
  
  
  RESULTS
  The mean follow-up period pre- and post-trabeculectomy was 3.9 years (min 0.9, max 10.7) and 3.8 years (min 2.0, max 8.0), respectively. The intraocular pressure (IOP) decreased from 18.1 mmHg (SD = 4.7) before trabeculectomy to 11.1 mmHg (SD = 2.9) at the last follow-up after trabeculectomy. The rate of MD loss was reduced with 56% on average, from -0.36 dB/year before surgery to -0.16 dB/year after surgery (p = 0.15).
  
  
  CONCLUSIONS
  Trabeculectomy considerably decreased the rates of change in the glaucomatous visual field.
authors.affiliation: Department of Ophthalmology, University Hospitals Leuven, Leuven, BelgiumInteruniversity Center for Biostatistics and Statistical Bioinformatics, Catholic University of Leuven and University of Hasselt, Leuven, Belgium.
authors.forename: Valérie
authors.initials: V
authors.lastname: Bertrand
authors.forename: Steffen
authors.initials: S
authors.lastname: Fieuws
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Stalmans
authors.forename: Thierry
authors.initials: T
authors.lastname: Zeyen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D014129:Trabecular Meshwork / Q000601:surgery*; D014130:Trabeculectomy; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*
keywords: glaucoma; intraocular pressure; mean deviation; rates of change; trabeculectomy; visual field