Clinical Availability of Ophthalmic Tests and PET Neuroimaging in Children with Cortical Visual Impairment

ABSTRACT

PURPOSE: We performed this study to determine if ophthalmic tests and positron-emission tomography (PET) would have any useful role in the investigation of cortical visual impairment (CVI) in children. METHODS: Ophthalmic tests were performed in children with CVI. After children with CVI and normal volunteers were examined using PET, PET images were transformed spatially on template images using Statistical Parametric Mapping 99 for analysis. The PET images of the CVI patients were compared with those of the normal group to display pixels with significantly decreased metabolism. Glucose metabolism in each patient was compared to that of the normal group and the number of pixels with decreased metabolism in each lobe was counted for analysis. RESULTS: Nine children with CVI showed variable degree of visual acuity. There were two patients with strabismus and one patient with latent nystagmus. In CVI group (n=5), there was a decrease of glucose metabolism in comparison with that of normal group (n=22) in occipital lobe as well as other areas, and the degree of decrease varied widely. The extent of the areas with decreased glucose metabolism in the occipital lobe of each patient ranged widely from 4% to 59%. CONCLUSIONS: The cerebral glucose metabolism was decreased with a variable degree in children with CVI. This result suggests that PET may be helpful in the diagnosis of children with CVI.