title: A method to measure and predict rates of regional visual field decay in glaucoma.
abstract: OBJECTIVE
  This study was conducted to measure the rate of visual field (VF) decay in glaucoma, to separate faster and slower components of decay, and to predict the rate of VF decay.
  
  
  METHODS
  Patients who had primary glaucoma and 6 or more years of follow-up were included. Thresholds at each VF location were regressed with linear, quadratic, and exponential models. The best model was used to parse the VF into slower and faster rate components. Two independent cohorts (glaucoma [n = 87] and cataract [n = 38]) were used to determine the technique's ability to distinguish areas of glaucomatous VF changes from those caused by cataract. VF forecasts, derived from the first half of follow-up, were compared with actual VF thresholds at the end of follow-up.
  
  
  RESULTS
  The mean (±SD) years of follow-up and number of VFs for the main cohort (389 eyes of 309 patients) were 8.2 (±1.1) years and 15.7 (±3.0), respectively. The proportions of best fits were linear 2%, quadratic 1%, and exponential 97%. Proportions of eyes with exponential rates of decay ≥10% for the entire visual field (VF), faster components, and slower components were 20%, 56%, and 4%, respectively. The difference in decay rates between the faster and slower components was greater in the independent glaucoma cohort (19% ± 10%) than in the cataract cohort (5% ± 5%; P < 0.001). Test location forecasts significantly correlated with measured values (r(2) = 0.67; P < 0.001).
  
  
  CONCLUSIONS
  This method isolates faster and slower components of VF decay in glaucoma, can identify patients who are fast progressors, and can predict patterns of future VF loss with appropriate confidence intervals. (ClinicalTrials.gov number, NCT00000148.).
authors.affiliation: Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles, California 90025, USA. caprioli@ucla.edu
authors.forename: Joseph
authors.initials: J
authors.lastname: Caprioli
authors.forename: Dennis
authors.initials: D
authors.lastname: Mock
authors.forename: Elena
authors.initials: E
authors.lastname: Bitrian
authors.forename: Abdelmonem A
authors.initials: AA
authors.lastname: Afifi
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Kouros
authors.initials: K
authors.lastname: Nouri-Mahdavi
authors.forename: Anne L
authors.initials: AL
authors.lastname: Coleman
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012607:Scotoma / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013997:Time Factors; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*