[Characteristics of hyperacuity sensitivity in normal and cyclovertical deviated subjects].
OBJECTIVE
To compare the sensitivity of hyperacuity of cyclovertical deviated patients with that of normal subjects.


METHODS
The sensitivity of hyperacuity was measured in 42 normal and 12 cyclovertical deviated patients, using a newly developed computerized device which randomly presents two targets opposed vertically or horizontally on a cathode ray tube(CRT) display.


RESULTS
In normal subjects, lower thresholds were obtained when the targets were aligned either vertically or horizontally. These highly sensitive ranges were defined as "the neutral zone of hyperacuity". An anisotropy of the sensitivity of hyperacuity was observed. i.e., better thresholds were obtained when the offset was set away from the neutral zone, whereas worse thresholds were obtained when the offset as close to the neutral zones. In cyclovertical deviated patients, the thresholds of hyperacuity were high around the neutral zones, which may indicate dysfunction of the central nervous system.


CONCLUSIONS
This analytical method may be useful to investigate the pathophysiology of the patients with cyclovertical deviations.
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Yasuma Eye Clinic, 4-10-50 Ohsu Naka-ku, Nagoya 460-0011, Japan.
Yasuma
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D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D006801:Humans; D008875:Middle Aged; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity