title: Evidence for a learning effect in short-wavelength automated perimetry.
abstract: OBJECTIVE
  To document the magnitude of any learning effect for short-wavelength automated perimetry (SWAP) in patients with either ocular hypertension (OHT) or open-angle glaucoma (OAG) who are experienced in standard automated perimetry (SAP).
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Thirty-five patients (22 with OHT and 13 with OAG) who had previously undergone at least 3 threshold SAP visual field examinations with the Humphrey Field Analyzer (HFA; Carl Zeiss Meditech Inc., Dublin, CA), and 9 patients with OHT who had not previously undertaken any form of perimetry.
  
  
  METHODS
  Each patient attended for SWAP on 5 occasions, each separated by 1 week. At each visit, both eyes were examined using Program 24-2 of the HFA; the right eye was always examined before the left eye.
  
  
  METHODS
  (1) Change over the 5 examinations, in each eye, of the visual field indices Mean Deviation (MD), Short-term Fluctuation (SF), Pattern Standard Deviation (PSD), and Corrected Pattern Standard Deviation. (2) Change in each eye between Visits 1 and 5 in proportionate Mean Sensitivity (pMS) for the central annulus of stimulus locations compared with that for the peripheral annulus thereby determining the influence of stimulus eccentricity on any alteration in sensitivity. (3) Change between Visits 1 and 5 in the number and magnitude of the Pattern Deviation (PD) probability levels associated with any alteration in sensitivity.
  
  
  RESULTS
  The MD, SF, and PSD each improved over the 5 examinations (each at P<0.001). The improvement in pMS between Visits 1 and 5 was greater for the peripheral annulus than for the central annulus by approximately twofold for the patients with OAG. Considerable variation was present between patients, within and between groups, in the number of locations exhibiting an improving sensitivity between Visits 1 and 5 by 1 or more PD probability levels.
  
  
  CONCLUSIONS
  Care should be taken to ensure that, during the initial examinations, apparent field loss with SWAP in patients exhibiting a normal field by SAP is not the result of inexperience in SWAP. Apparently deeper or wider field loss in the initial examinations with SWAP compared with that exhibited by SAP in OAG also may arise from inexperience in SWAP.
authors.affiliation: Cardiff School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom. wildjm@cardiff.ac.uk
authors.forename: John M
authors.initials: JM
authors.lastname: Wild
authors.forename: Linda S
authors.initials: LS
authors.lastname: Kim
authors.forename: Ian E
authors.initials: IE
authors.lastname: Pacey
authors.forename: Ian A
authors.initials: IA
authors.lastname: Cunliffe
mesh_terms: D000328:Adult; D000368:Aged; D005189:False Positive Reactions; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D007858:Learning; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields