title: Longitudinal and cross-sectional analyses of visual field progression in participants of the Ocular Hypertension Treatment Study.
abstract: OBJECTIVE
  To assess agreement between longitudinal and cross-sectional analyses for determining visual field progression in data from the Ocular Hypertension Treatment Study.
  
  
  METHODS
  Visual field data from 3088 eyes of 1570 participants (median follow-up, 7 years) were analyzed. Longitudinal analyses were performed using change probability with total and pattern deviation, and cross-sectional analyses were performed using the glaucoma hemifield test, corrected pattern standard deviation, and mean deviation. The rates of mean deviation and general height change were compared to estimate the degree of diffuse loss in emerging glaucoma.
  
  
  RESULTS
  Agreement on progression in longitudinal and cross-sectional analyses ranged from 50% to 61% and remained nearly constant across a wide range of criteria. In contrast, agreement on absence of progression ranged from 97.0% to 99.7%, being highest for the stricter criteria. Analyses of pattern deviation were more conservative than analyses of total deviation, with a 3 to 5 times lesser incidence of progression. Most participants developing field loss had both diffuse and focal changes.
  
  
  CONCLUSIONS
  Despite considerable overall agreement, 40% to 50% of eyes identified as having progressed with either longitudinal or cross-sectional analyses were identified with only one of the analyses. Because diffuse change is part of early glaucomatous damage, pattern deviation analyses may underestimate progression in patients with ocular hypertension.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada. paul@dal.ca
authors.forename: Paul H
authors.initials: PH
authors.lastname: Artes
authors.forename: Balwantray C
authors.initials: BC
authors.lastname: Chauhan
authors.forename: John L
authors.initials: JL
authors.lastname: Keltner
authors.forename: Kim E
authors.initials: KE
authors.lastname: Cello
authors.forename: Chris A
authors.initials: CA
authors.lastname: Johnson
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Anderson
authors.forename: Mae O
authors.initials: MO
authors.lastname: Gordon
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kass
mesh_terms: D003430:Cross-Sectional Studies; D018450:Disease Progression; D005901:Glaucoma / Q000517:prevention & control; D006801:Humans; D008137:Longitudinal Studies; D009798:Ocular Hypertension / Q000503:physiopathology*; D015203:Reproducibility of Results; D014786:Vision Disorders / Q000503:physiopathology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*