Effects of Random Presentation on Kinetic Threshold

The authors carried out perimetric tests to evaluate the influence of kinetic stimuli randomization on the threshold. The same target was presented first in a sequential manner (the examined subject knowing in advance the target direction) and afterwards in a randomized manner (the subject ignoring the stimulus direction). Both normal subjects (10 individuals) and patients suffering from visual field defects due to various pathological conditions (10 individuals) were tested. All tests were repeated five times in order to evaluate long term fluctuations of the kinetic threshold. The automated Goldmann Perimeter Perikon was employed to obtain good fixation control and consistency of the examination conditions. Stimuli randomization caused a significant isopteric contraction. On the other hand, sequential stimulus exposure seemed to assume more consistent results in repeated examinations, provided that the subjects showed a good attention level.