Abstract
Purpose: :
Recently semi-automated or full-automated kinetic visual field measuring machines have been developed.By measuring Reaction time (RT), or the necessary time for the subject to respond after s/he sees the target, correction of the kinetic threshold is possible.However, there are a few reports on RT in kinetic visual field testing and we found no report about the relationship of target speed and RT. The present study describes the relationship of target speed and RT in normal subjects using automated perimeter.
Methods: :
Five eyes of 5 normal subjects (4 males, 1 female; age 30.6 ±2.6) were examined with Goldmann Kinetic Perimetry using the kinetic measuring program for Octopus900. The target luminance and size were III/4e, I/4e, I/3e, I/2e, and I/1e. The targets were lacated on the meridians of 45°, 135°, 225°and 315°. The target speed was changed for 10 stages; 1 to 10°/s. After confirming the responding points, RT-vector was arranged to examine the relationship of each target speed and RT.
Results: :
RT for each target at III/4e was as follows; 751.0 ms (1°/s), 374.3 ms (5°/s) and 338.7 ms (10°/s). In the same way, at I/4e, 606.0 ms (1°/s), 423.0 ms (5°/s) and 391.7 ms (10°/s); at I/3e, 938.0 ms (1°/s), 471.0 ms (5°/s) and 381.0 ms (10°/s); at I/2e, 1279.7 ms (1°/s), 504.3 ms (5°/s) and 464.3 ms (10°/s); at I/1e, 1374.7 ms (1°/s), 391.3 ms (5°/s) and 368.7 ms (10°/s). Under all the conditions, the slower the target speed, the longer the RT became. Hence, target speed is considered one of the factors for RT fluctuation.
Conclusions: :
When RT correction is conducted in the kinetic visual field measurement with automated perimeter, RT should be evaluated at the same speed as the target speed actually used.