Comparison between anisometropic and strabismic amblyopia using functional magnetic resonance imaging.
OBJECTIVE
To assess calcarine activation with functional magnetic resonance imaging (fMRI) in patients with anisometropic and strabismic amblyopia.


METHODS
14 amblyopes (eight anisometropic and six strabismic) were studied with fMRI using stimuli of checkerboards of various checker sizes and temporal frequencies. While T2* weighted MRI were obtained every 3 seconds for 6 minutes, patients viewed the stimuli monocularly with either the amblyopic or sound eye.


RESULTS
Amblyopic eyes showed reduced calcarine activation compared with contralateral sound eyes in fMRI in all subjects. The calcarine activation from amblyopic eyes in anisometropic amblyopes was more suppressed at higher spatial frequencies, while that from amblyopic eyes in strabismic amblyopes was more suppressed at lower spatial frequencies.


CONCLUSIONS
These results suggest that fMRI is a useful tool for the study of amblyopia in humans. The calcarine activation via amblyopic eyes because of anisometropia or strabismus has different temporospatial characteristics, which suggests differences in the neurophysiological mechanisms between two types of amblyopia.
Choi
M Y
MY
Department of Ophthalmology, College of Medicine, Chungbuk National University, Korea.
Lee
K M
KM
Hwang
J M
JM
Choi
D G
DG
Lee
D S
DS
Park
K H
KH
Yu
Y S
YS
D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009778:Occipital Lobe / Q000378:metabolism; D013285:Strabismus / Q000150:complications* / Q000378:metabolism