Evaluation of numerical displays of visual field data by human observers--the definition of scotomas and clusters by human interpreters.
Numerical printouts of 23 visual field examinations performed with glaucoma program G1 were analyzed by 3 perimetrists. The task consisted of defining the existence of clusters or scotomas. Considerable discrepancy with regard to the existence or the size of clusters and/or scotomas was found among the three perimetrists. The median difference in number of clusters as compared for each pair of interpreters was found to differ from zero at a significance level of 5% (Wilcoxon's signed-rank nonparametric test). These findings suggest that the interpretation of a visual field status by human observers will always remain subjective and to a large extent contradictory. This situation calls for the implementation of interpretative computer software to supplement the currently available algorithms.
Fankhauser
F
F
Lindenhof Hospital, Berne, Switzerland.
Larsen
S E
SE
Cruz-Orive
L M
LM
Fankhauser
F
F
Giger
H
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005069:Evaluation Studies as Topic; D005901:Glaucoma / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D009798:Ocular Hypertension / Q000503:physiopathology; D012607:Scotoma / Q000503:physiopathology*; D014786:Vision Disorders / Q000503:physiopathology*; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields