title: The statistical interpretation of blue-on-yellow visual field loss.
abstract: OBJECTIVE
  To evaluate short-wavelength-sensitive perimetry in the detection of glaucomatous field loss.
  
  
  METHODS
  The sample consisted of 27 normal subjects, 24 patients with primary open angle glaucoma (POAG), and 27 patients with ocular hypertension (OHT). Blue-on-yellow (B-Y) and standard (W-W) perimetry was undertaken with a modified Humphrey Field Analyzer 640 on one eye of each subject and patient. The B-Y data were corrected for individual ocular media absorption. Results were compared to an age-matched normal database of 50 subjects (age range, 60 to 82 years; mean age, 70.0 years; SD, 6.4 years). Visual field indices and total and pattern deviation probability maps were calculated for both W-W and B-Y fields.
  
  
  RESULTS
  The B-Y normal database exhibited increased between-subject variability compared to the W-W normal database (P < 0.001). The greater variability increased with the increase in eccentricity (P < 0.001) and with the increase in age (P = 0.032). All patients with POAG exhibited B-Y field loss; 11 demonstrated greater B-Y loss than the corresponding W-W field. In advanced POAG, the B-Y and the W-W fields were similar. Twenty-five of the 27 normal subjects exhibited normal B-Y fields. Five of the 27 patients with OHT manifested B-Y focal abnormality and a normal W-W field: in two, W-W focal loss subsequently developed.
  
  
  CONCLUSIONS
  Short-wavelength-sensitive perimetry can identify visual field loss before that detected by W-W perimetry. However, the increased between-subject variability necessitates stringent statistical analysis in the definition of abnormality.
authors.affiliation: Department of Vision Sciences, Aston University, United Kingdom.
authors.forename: J M
authors.initials: JM
authors.lastname: Wild
authors.forename: I D
authors.initials: ID
authors.lastname: Moss
authors.forename: D
authors.initials: D
authors.lastname: Whitaker
authors.forename: E C
authors.initials: EC
authors.lastname: O'Neill
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception; D003627:Data Interpretation, Statistical; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis*; D011336:Probability; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods / Q000706:statistics & numerical data; D014794:Visual Fields