Binocularity and spatial frequency dependence of calcarine activation in two types of amblyopia

• Published in: Neuroscience research 2001-06, Vol.40 (2), p.147-153
• Main Authors: Lee, Kyoung-Min, Lee, Soo-Hwa, Kim, Na-Young, Kim, Chai-Youn, Sohn, Jung-Woo, Choi, Mi Young, Gyu Choi, Dong, Hwang, Jung-Min, Ho Park, Ki, Lee, Dong Soo, Suk Yu, Young, Hyun Chang, Kee
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Amblyopia; Amblyopia - etiology; Amblyopia - pathology; Amblyopia - physiopathology; Anisometropia; Anisometropia - complications; Anisometropia - pathology; Anisometropia - physiopathology; Brain activation; Cerebrovascular Circulation - physiology; Child; Child, Preschool; Evoked Potentials, Visual - physiology; Female; fMRI; Humans; Magnetic Resonance Imaging; Male; Pattern Recognition, Visual - physiology; Photic Stimulation; Space Perception - physiology; Strabismus; Strabismus - complications; Strabismus - pathology; Strabismus - physiopathology; Vision, Binocular - physiology; Visual cortex; Visual Cortex - pathology; Visual Cortex - physiopathology
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/S0168-0102(01)00220-6

Objective and Background: Strabismus and anisometropia early in life frequently causes monocular amblyopia. Activation of the visual cortex is compared between the two types of amblyopia to elucidate differences in the pathogenetic mechanism of the disease. Methods: Using an EPI gradient echo sequence in 1.5T MRI, calcarine activation by monocular viewing of checkerboard patterns with reversal was examined in terms of binocularity of the activation and dependence on the spatial frequency of the stimuli. Results: First, the proportion of voxels activated by both normal and amblyopic eye monocular stimulations is lower in the strabismic group than in the anisometropic group. Second, the activation by higher-spatial-frequency stimuli is reduced in the anisometropic group, but not in the strabismic group. Conclusions: These findings from the human visual cortex are consistent with the view proposed based on animal research that the loss of binocular interaction and the undersampling of high-spatial-frequency components of visual stimuli are each one of the underlying changes in strabismic and anisometropic amblyopia, respectively.