title: Asymmetries and visual field summaries as predictors of glaucoma in the ocular hypertension treatment study.
abstract: OBJECTIVE
  To evaluate whether baseline visual field data and asymmetries between eyes predict the onset of primary open-angle glaucoma (POAG) in Ocular Hypertension Treatment Study (OHTS) participants.
  
  
  METHODS
  A new index, mean prognosis (MP), was designed for optimal combination of visual field thresholds, to discriminate between eyes that developed POAG from eyes that did not. Baseline intraocular pressure (IOP) in fellow eyes was used to construct measures of IOP asymmetry. Age-adjusted baseline thresholds were used to develop indicators of visual field asymmetry and summary measures of visual field defects. Marginal multivariate failure time models were constructed that relate the new index MP, IOP asymmetry, and visual field asymmetry to POAG onset for OHTS participants.
  
  
  RESULTS
  The marginal multivariate failure time analysis showed that the MP index is significantly related to POAG onset (P < 0.0001) and appears to be a more highly significant predictor of POAG onset than either mean deviation (MD; P = 0.17) or pattern standard deviation (PSD; P = 0.046). A 1-mm Hg increase in IOP asymmetry between fellow eyes is associated with a 17% increase in risk for development of POAG. When threshold asymmetry between eyes existed, the eye with lower thresholds was at a 37% greater risk of development of POAG, and this feature was more predictive of POAG onset than the visual field index MD, though not as strong a predictor as PSD.
  
  
  CONCLUSIONS
  The MP index, IOP asymmetry, and binocular test point asymmetry can assist in clinical evaluation of eyes at risk of development of POAG.
authors.affiliation: Department of Mathematics and Statistics, San Diego State University, San Diego, California 92182, USA. ralevine@sciences.sdsu.edu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Levine
authors.forename: Shaban
authors.initials: S
authors.lastname: Demirel
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Fan
authors.forename: John L
authors.initials: JL
authors.lastname: Keltner
authors.forename: Chris A
authors.initials: CA
authors.lastname: Johnson
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kass
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000517:prevention & control; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy; D011379:Prognosis; D012307:Risk Factors; D013997:Time Factors; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields
chemical_list: D000959:Antihypertensive Agents