Characteristics of glucose metabolism in the visual cortex of amblyopes using positron-emission tomography and statistical parametric mapping.
BACKGROUND
The effects of amblyopia on the glucose metabolism in the visual cortex in the resting state are evaluated, the asymmetry of glucose metabolism in the ipsilateral and the contralateral occipital lobes was examined by comparing the number of hypometabolic pixels in both occipital lobes, and the correlation between this asymmetry and the results of the ophthalmologic tests was evaluated.


METHODS
Eleven amblyopes (7 anisometropic and 4 strabismic) and 12 normal subjects were studied with their eyes open, but without any further visual stimulus using F-18-fluorodeoxyglucose positron-emission tomography (PET) and statistical parametric mapping. Ophthalmologic tests including stereoacuity, contrast sensitivity function, monocular optokinetic nystagmus, and visual evoked potential (VEP) were measured.


RESULTS
Compared to normal subjects, glucose metabolism decreased in Brodmann area (BA) 17, BAs 18/19, both inferior temporal lobes (BAs 37 and 20), and the superior parietal lobe (BA 7) in amblyopic patients, regardless of strabismic or anisometropic amblyopia. The laterality index of the hypometabolic pixels in the occipital lobe closely correlated with the asymmetry in the latency time of VEP (r = 0.82, P <0.05).


CONCLUSIONS
These results suggest that PET imaging of glucose metabolism can provide a functional mapping of the visual cortex in human amblyopia.
Choi
Mi Young
MY
Department of Ophthalmology, College of Medicine, Chungbuk National University, Seoul, Korea.
Lee
Dong Soo
DS
Hwang
Jeong-Min
JM
Choi
Dong Gyu
DG
Lee
Kyoung-Min
KM
Park
Ki Ho
KH
Yu
Young Suk
YS
D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015350:Contrast Sensitivity; D005074:Evoked Potentials, Visual; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D017120:Nystagmus, Optokinetic; D014055:Tomography, Emission-Computed; D014792:Visual Acuity; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology
D019788:Fluorodeoxyglucose F18; D005947:Glucose