title: The influence of patient reliability on visual field outcome.
abstract: The reliability of subjects to perform to perimetry correctly should be carefully evaluated to interpret visual field examinations adequately. Clinicians generally agree that numerous false-positive responses to catch trials cause measured thresholds to be falsely high and numerous false-negative responses cause measured thresholds to be falsely low. We studied the effect of false-positive and false-negative responses on the outcome of visual field measurements. Of 47 eyes, the results of 106 stable glaucomatous visual field tests (Program G1, Octopus 201, Interzeag, Schlieren, Switzerland) with false-positive responses and no more than one false-negative response to catch trials were compared to the results of reliable visual field tests (no false-positive and no more than one false-negative response) performed on the same eye. Similarly, 60 stable visual fields with false-negative responses and no more than one false-positive response were used to study the effect of false-negative responses on visual field sensitivities. Linear regression analysis disclosed a mean sensitivity increase of 1.5 dB for every 10% of false-positive responses (r = .34, P = .000) and a mean sensitivity decrease of 1.2 dB for every 10% of false-negative responses (r = .26, P = .04). These results may be used to help reduce the magnitude of unexplained long-term fluctuation in visual field interpretation.
authors.affiliation: Department of Ophthalmology and Visual Science, Yale University, New Haven, CT.
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.forename: M
authors.initials: M
authors.lastname: Zulauf
authors.forename: J
authors.initials: J
authors.lastname: Caprioli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D058609:Visual Field Tests / Q000592:standards*; D014794:Visual Fields / Q000502:physiology*