title: Improved estimates of visual field progression using bayesian linear regression to integrate structural information in patients with ocular hypertension.
abstract: OBJECTIVE
  To assess whether neuroretinal rim area (RA) measurements of the optic disc could be used to improve the estimate of the rate of change in visual field (VF) mean sensitivity in patients with ocular hypertension (OHT) using a Bayesian linear regression (BLR), compared to a standard ordinary least squares linear regression (OLSLR) of mean sensitivity (MS) measurements alone.
  
  
  METHODS
  MS and RA measurements were analyzed from a longitudinal series of 179 patients with OHT visiting Moorfields Eye Hospital between 1992 and 2000. For each patient, linear regression of RA was computed after an appropriate transformation to "scale" RA with MS measurements, and the slope coefficient from this regression was used as a prior for BLR of MS. The BLR then was compared with the OLSLR approach by evaluating how accurately each regression technique predicted future MS measurements.
  
  
  RESULTS
  On average, BLR was significantly more accurate than OLSLR for series up to 8 measurements long (root-mean-square prediction error [RMSPE] was 0.14 decibels [dB] smaller with BLR than OLSLR; P < 0.001, Wilcoxon signed-rank test), with OLSLR of VF data alone being more accurate for longer series (RMSPE was 0.06 dB smaller with OLSLR than BLR).
  
  
  CONCLUSIONS
  BLR provides a significantly more accurate estimate of the rate of change in MS than the standard OLSLR approach, especially in short time series, suggesting that structural measurements can be used successfully in statistical models to assist clinicians monitoring VF progression in patients with OHT. Further studies are necessary to validate the method in glaucoma patients.
authors.affiliation: NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Russell
authors.forename: Rizwan
authors.initials: R
authors.lastname: Malik
authors.forename: Balwantray C
authors.initials: BC
authors.lastname: Chauhan
authors.forename: David P
authors.initials: DP
authors.lastname: Crabb
authors.forename: David F
authors.initials: DF
authors.lastname: Garway-Heath
mesh_terms: D000368:Aged; D001499:Bayes Theorem; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D009898:Optic Disk / Q000473:pathology; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*