[Study of functional magnetic resonance imaging in strabismic and anisometropic amblyopic patients].
OBJECTIVE
To elucidate the difference in the pathogenesis between strabismic amblyopia and anisometropic amblyopia.


METHODS
Using an EPI gradient echo sequence in 1.5 T MRI and visual electrophysiological system, the pattern visual evoked potentials and calcarine activation by monocular viewing of check-board pattern with reversal were examined in 18 strabismic amblyopes and 15 anisometropic amblyopes. The calcarine activation in terms of binocular voxels index and dependence on the spatial frequency of the stimuli were compared. The correlation between PVEP P(100) latency and activation intensity was also analyzed.


RESULTS
The binocular voxels index was lower in the strabismic amblyope than that in the anisometropic amblyope. The calcarine activation from amblyopic eyes in strabismic amblyopes was more suppressed at higher spatial frequencies (1, 2 c/d); while that from amblyopic eyes in anisometropic amblyopes was more suppressed at all spatial frequencies (0.25, 0.5, 1 and 2 c/d). Inverse correlations existed between PVEP P(100) latency and activation intensity in two types amblyopia (P < 0.05).


CONCLUSIONS
The binocular interaction is not equal in these two different types of amblyopia. Meanwhile, the amblyopia-related deficits in the low and high-spatial-frequency pathway of visual system are not similar between these two different types of amblyopia.
Liu
Hu
H
Tianjin Eye Hospital, Tianjin 300040, China.
Zhao
Kan-xing
KX
Chen
Min
M
Zhou
Tian-gang
TG
D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000175:diagnosis / Q000503:physiopathology*; D002648:Child; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012030:Refractive Errors / Q000503:physiopathology*; D013285:Strabismus / Q000175:diagnosis / Q000503:physiopathology*; D014793:Visual Cortex / Q000502:physiology