Physiologic statokinetic dissociation is eliminated by equating static and kinetic perimetry testing procedures.
In the present study, we measured the extent of statokinetic dissociation (SKD) in normal observers and then equated the psychophysical tasks into a two-interval forced choice (2IFC) procedure. In Experiment 1, we used the Humphrey visual field analyzer in static perimetry and automated kinetic perimetry modes to measure contrast sensitivity thresholds and the Goldmann manual kinetic perimeter to measure isopters. This was carried out using a Goldmann size II target. Goldmann kinetic perimetry was performed manually with both inward (peripheral to center) and outward (center to periphery) directions of movement to deduce an "average" isopter. This revealed the presence of SKD when superimposed upon the map of static contrast threshold results. There was no evidence of any contribution of examiner technique or instrument-specific differences to SKD. In Experiment 2, we determined the psychometric curves plotting proportion seen as a function of stimulus eccentricity with static and kinetic stimuli with a 2IFC procedure and method of constant stimuli. In an additional experiment, we also showed that subjects were able to reliably discriminate whether a stimulus was static, moving inward, or moving outward, and hence, comparisons could be made between static and kinetic perimetry tasks. Overall, by making the task objective and reducing criterion bias, eccentricity thresholds were equated across static and kinetic perimetry methods; hence, no evidence of SKD was seen. We suggest SKD is inherent to the differences in methodology of threshold measurement in conventional static and kinetic perimetry and individual criterion bias.
Centre for Eye Health, University of New South Wales, Kensington, NSW, AustraliaSchool of Optometry and Vision Science, University of New South Wales, Kensington NSWjphu@cfeh.com.au.
Jack
J
Phu
School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, AustraliaDepartment of Optometry and Vision Science, King Saud University, Kingdom of Saudi Arabianoha.alsaleem@student.unsw.edu.au.
Noha
N
Al-Saleem
Centre for Eye Health, University of New South Wales, Kensington, NSW, AustraliaSchool of Optometry and Vision Science, University of New South Wales, Kensington NSWm.kalloniatis@unsw.edu.au.
Michael
M
Kalloniatis
School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australias.khuu@unsw.edu.au.
Sieu K
SK
Khuu
D000328:Adult; D002755:Choice Behavior; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011601:Psychophysics; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult