Abstract
Purpose:
There have been several reports in which the relationships between target speed and simple visual reaction time (RT) in kinetic perimetry were investigated. In those previous studies, the RT was measured at the locations of sufficient suprathreshold. Such RT may not necessarily equal the RT at the location of kinetic threshold (KT). In this study, we measured the RT at the location of KT to investigate the relationship between the target speed and RT.
Methods:
Five normal eyes of 5 subjects (2 males, 3 females; range of age: 31-38 years) were tested using the Goldmann kinetic perimetry program in Octopus 900 with the target luminance and size of III/4e, I/4e, I/3e, I/2e and I/1e, and with ten kinds of target speed from 1°/s to 10°/s. First, the response point for each kinetic target was measured along the meridians of 135° and 225°. After that, the target was moved perpendicularly from the point 1° outside of the response point on the meridians at each target speed. When there was a response, the same target was presented from 1° farther outside, and the outermost response point was determined as KT for each target speed. Next, RT of each target at the location of KT was measured using the “RT-vector” procedure. If the target was not seen, the target was moved inward 1° by 1° until there was a response.
Results:
The RTs measured at the locations of KT were 708.5 ms (1°/s), 604.8 ms (2°/s), 462.0 ms (3°/s), 402.3 ms (4°/s), 414.8 ms (5°/s), 418.5 ms (6°/s), 385.8 ms (7°/s), 366.3 ms (8°/s), 366.3 ms (9°/s) and 349.0 ms (10°/s) with target of I/4e. It was also observed with target of III/4e, I/3e, I/2e and I/1e that the RT increased as the target speed decreased between 1° and 10°/s.
Conclusions:
If we correct KT with RT in automated kinetic perimetry, RT should be evaluated at the same speed as the target speed used actually.
Keywords: 758 visual fields •
642 perimetry