title: Contrast sensitivity perimetry and clinical measures of glaucomatous damage.
abstract: OBJECTIVE
  To compare conventional structural and functional measures of glaucomatous damage with a new functional measure-contrast sensitivity perimetry (CSP-2).
  
  
  METHODS
  One eye each was tested for 51 patients with glaucoma and 62 age-similar control subjects using CSP-2, size III 24-2 conventional automated perimetry (CAP), 24-2 frequency-doubling perimetry (FDP), and retinal nerve fiber layer (RNFL) thickness. For superior temporal (ST) and inferior temporal (IT) optic disc sectors, defect depth was computed as amount below mean normal, in log units. Bland-Altman analysis was used to assess agreement on defect depth, using limits of agreement and three indices: intercept, slope, and mean difference. A criterion of p < 0.0014 for significance used Bonferroni correction.
  
  
  RESULTS
  Contrast sensitivity perimetry-2 and FDP were in agreement for both sectors. Normal variability was lower for CSP-2 than for CAP and FDP (F > 1.69, p < 0.02), and Bland-Altman limits of agreement for patient data were consistent with variability of control subjects (mean difference, -0.01 log units; SD, 0.11 log units). Intercepts for IT indicated that CSP-2 and FDP were below mean normal when CAP was at mean normal (t > 4, p < 0.0005). Slopes indicated that, as sector damage became more severe, CAP defects for IT and ST deepened more rapidly than CSP-2 defects (t > 4.3, p < 0.0005) and RNFL defects for ST deepened more slowly than for CSP, FDP, and CAP. Mean differences indicated that FDP defects for ST and IT were on average deeper than RNFL defects, as were CSP-2 defects for ST (t > 4.9, p < 0.0001).
  
  
  CONCLUSIONS
  Contrast sensitivity perimetry-2 and FDP defects were deeper than CAP defects in optic disc sectors with mild damage and revealed greater residual function in sectors with severe damage. The discordance between different measures of glaucomatous damage can be accounted for by variability in people free of disease.
authors.affiliation: *PhD, FAAO †OD, FAAO ‡OD, MS, FAAO §MD, PhD Indiana University School of Optometry, Bloomington, Indiana (WHS, VEM, JKT, BMS, DGH); State University of New York (SUNY) College of Optometry, New York, New York (MWD); and NIHR Biomedical Research Centre for Ophthalmology at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom (RM).
authors.forename: William H
authors.initials: WH
authors.lastname: Swanson
authors.forename: Victor E
authors.initials: VE
authors.lastname: Malinovsky
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Dul
authors.forename: Rizwan
authors.initials: R
authors.lastname: Malik
authors.forename: Julie K
authors.initials: JK
authors.lastname: Torbit
authors.forename: Bradley M
authors.initials: BM
authors.lastname: Sutton
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Horner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000473:pathology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*