Mechanism of neurophysiological treatment of amblyopia using functional magnetic resonance imaging.

PURPOSE: To research the mechanism of neurophysiological treatment of amblyopia by observing the visual cortex activation under rotating grating stimulus with functional magnetic resonance imaging (MRI), and identify the components of the activation.

METHODS

Nine healthy volunteers were examined using gradient-recalled echo and echo-planar imaging (GRE-EPI) pulse sequence performed at the 1.5 Tesla MRI scanner. In the block designing, rotating grating, stationary grating and luminance were plotted as task states, stationary grating, luminance and darkness as control states, respectively. The tasks of stimuli included 6 steps. Imaging processing and statistical analysis were carried out off-line using statistical parametric mapping (SPM99) software in single-subject.

RESULTS

Some individual areas of visual cortex were activated by various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe related to the stimuli of luminance, bilateral activation of Brodmann's 19th area related to visual motion perception, and the mild activation in the middle of occipital lobe related to form perception.

CONCLUSION

The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception and form perception. Functional MRI has potential as a tool for studying the physiological mechanism of visual cortex.