Related Experiment Video
Updated: Aug 20, 2026
Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition
Published on: July 21, 2020
Differential activation of cerebral blood flow by stimulating amblyopic and fellow eye
Shoichi Mizoguchi1, Yukihisa Suzuki, Motohiro Kiyosawa
1Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Purpose:
Positron emission tomography (PET), the blood flow response in the primary visual cortex (V1) to two visual stimuli, low temporal frequency (6 Hz) to activate the parvocellular system, and high temporal frequency (25 Hz) to activate the magnocellular system were used to investigate pathophysiologic mechanism of amblyopia.
Methods:
Five women and one man who were aged between 26 and 60 years, who were ophthalmologically normal except for amblyopia, and who had corrected visual acuity in the amblyopic eye of 0.6 or worse were examined. An intravenous injection of the H(2)(15)O was given, and the regional cerebral blood flow was measured by PET during full-field stimulation with either 6 Hz or 25 Hz flicker to the amblyopic or the sound eye.
Result:
The activation of blood flow in the contra-lateral area V1 by the 6-Hz stimulation of the sound eye was greater than that during the stimulation of the amblyopic eye (P<0.05, small volume correction, n=6). With 25-Hz stimulation of the sound and amblyopic eyes, the blood flow in the contra-lateral and ipsi-lateral areas V1 was not significantly different.
Conclusion:
The decreased activation of blood flow in the contra-lateral V1 by low temporal frequency stimuli supports the hypothesis that the parvocellular pathway in amblyopic eyes is depressed.
