Purpose: To assess patient reliability and compliance, most perimeters check for false-positive and -negative answers. In this study the results of catch trials were obtained with video campimetry with respect to age-related changes and differences for tests using increment and decrement stimuli.
Methods: Sixty-one ophthalmologically normal persons (aged 20-80 years) were tested with automated campimetry on a computer screen. Examination strategy included bright and dark 1 degree-stimuli at 69 test locations within the central 30 degrees of the visual field (presented on a computer screen). Four percent of all stimulus presentations were used for testing false-positive answers, 4% for false-negative answers.
Results: The rate of false-positive answers was not significantly age-related and there was no difference for tests with dark and bright stimuli. Concerning false-negative answers, no difference between dark and bright stimuli was found. There was also no strong correlation with age.
Conclusion: In this study rates of false-positive and -negative answers were low at a comparable level for either stimulus type (bright/dark) or age of the tested persons.