Factors influencing reaction time during automated kinetic perimetry on the Tübingen computer campimeter.

PURPOSE

To determine the effect of age, examination, location, luminance, subject, and vigilance on reaction time (RT) in automated kinetic perimetry.

METHODS

Thirty-six normal volunteers (20-70 years old) underwent kinetic campimetric examinations, during which RTs (time from appearance of a stimulus to response) were recorded. Stimuli with a diameter of 26 minutes of arc (Goldmann III) were presented on horizontal vectors with an angular velocity of 2 deg/s. Thirty-two positions in the 30 degrees radius visual field were tested six times, at luminance levels of 41.62 and 110 cd/m2 (background 10 cd/m2). An analysis of RT variance (ANCOVA) was performed.

RESULTS

Median RT increased with age from 370 ms (20-30-year-old subjects) to 440 ms (60-70-year-old subjects). There was a strong dependency of RT from the individual subjects examined (means range, 313-411 ms), from the course of one examination period, from the examination and stimulus luminance, and from the location in the visual field.

CONCLUSIONS

Reaction time during automated kinetic perimetry varies considerably. This study shows that the factors of age, the subject examined, his or her daily condition, the course within one examination period, and the stimulus location and luminance are of relevance. For a much more reliable prediction of individual RTs and thus a precise assessment of local kinetic thresholds, application of some additional kinetic stimuli (RT time vectors) within the intact visual field areas is necessary.