title: Canadian Glaucoma Study: 3. Impact of risk factors and intraocular pressure reduction on the rates of visual field change.
abstract: OBJECTIVE
  To determine rates of visual field change associated with risk factors for progression in the Canadian Glaucoma Study (abnormal anticardiolipin antibody level, age, female sex, and mean follow-up intraocular pressure [IOP]), and to evaluate the effect of IOP reduction on subsequent rates of visual field change in progressing patients.
  
  
  METHODS
  Two hundred sixteen patients (median age, 65.2 years) were followed up at 4-month intervals with perimetry and were monitored for progression. Patients reaching an end point based on total deviation analysis underwent 20% or greater reduction in IOP. Rates of mean deviation (MD) change were calculated.
  
  
  RESULTS
  Patients with 0, 1, and 2 end points had a median of 18, 23, and 25 examinations, respectively. The median MD rate in progressing patients prior to the first end point was significantly worse compared with those with no progression (-0.35 and 0.05 dB/y, respectively). An abnormal anticardiolipin antibody level was associated with a significantly worse MD rate compared with a normal anticardiolipin antibody level (-0.57 and -0.03 dB/y, respectively). Increasing age was associated with a worse MD rate, but female sex and mean follow-up IOP were not. After the first end point, the median IOP decreased from 18.0 to 14.8 mm Hg (20% in individual patients), resulting in a significant MD rate change from -0.36 to -0.11 dB/y.
  
  
  CONCLUSIONS
  Patients with abnormal anticardiolipin antibody levels and increasing age had faster visual field change. Modest IOP reduction in progressing patients significantly ameliorated the rate of visual field decline.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00262626.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Dalhousie University, Victoria, Halifax, Nova Scotia B3H 2Y9, Canada. bal@dal.ca
authors.forename: Balwantray C
authors.initials: BC
authors.lastname: Chauhan
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Mikelberg
authors.forename: Paul H
authors.initials: PH
authors.lastname: Artes
authors.forename: A Gordon
authors.initials: AG
authors.lastname: Balazsi
authors.forename: Raymond P
authors.initials: RP
authors.lastname: LeBlanc
authors.forename: Mark R
authors.initials: MR
authors.lastname: Lesk
authors.forename: Marcelo T
authors.initials: MT
authors.lastname: Nicolela
authors.forename: Graham E
authors.initials: GE
authors.lastname: Trope
mesh_terms: D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000276:immunology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*
chemical_list: D017153:Antibodies, Anticardiolipin