Structure-function correlations of glaucoma in Filipinos

Introduction@#To determine the structure-function correlations of glaucoma in Filipinos using the average peripapillary retinal nerve fiber layer (RNFL) thickness and rim area (RA) of the spectral-domain optical coherence tomography (SD-OCT) and mean defect (MD), pattern standard deviation (PSD), and visual field (VF) clusters of standard automated perimetry (SAP)@*Methods@#Consecutive tests consisting of SD-OCT, SAP, and disc photos were reviewed and selected based on abnormalities in VFs or OCTs or both. Each set of tests was classified as to VF defect type and severity. Mean threshold of VF clusters, MD, and PSD were correlated with average and sectoral RNFL thicknesses and RA. @*Results@#One hundred eighty-six (168) eyes of 121 patients with mean age of 60.2 ± 14.7 years had an average MD, PSD, RNFL thickness, RA of -9.5 ± 8.5 dB, 5.4 ± 3.3 dB, 75.9 ± 15.9 μm, and 0.9 ± 0.4 mm2, respectively. Among VF tests, 23.1% were normal, 16.5% had early, 9.1% moderate, 12.4% advanced, and 8.3% severe glaucoma damage. Most common VF defect types were central islands, combined, and paracentral (16.5%, 14.4%, and 12.2%, respectively). The most commonly affected RNFL segments were inferior, followed by superior, and combined superior and inferior (51.2%, 47.1, and 34%, respectively). Among the OCT parameters, RNFL thickness and RA were strongly correlated (p<0.0001). Between the VF and OCT parameters, the strongest correlation was between the clusters of superior VF defects and the 6-8 o’clock RNFL thinning, followed by the inferior VF defects and the 12-1 o’clock RNFL thinning. Inferior RNFL thinning was strongly correlated with MD and PSD. @*Conclusion@#Among Filipino glaucomatous eyes monitored with SD-OCT and SAP, correlation was strongest between the superior VF defects and the infero-temporal RNFL thinning.

Interregional correlations of glucose metabolism between the basal ganglia and different cortical areas: an ultra-high resolution PET/MRI fusion study using 18F-FDG

Basal ganglia have complex functional connections with the cerebral cortex and are involved in motor control, executive functions of the forebrain, such as the planning of movement, and cognitive behaviors based on their connections. The aim of this study was to provide detailed functional correlation patterns between the basal ganglia and cerebral cortex by conducting an interregional correlation analysis of the 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) data based on precise structural information. Fifteen participants were scanned with 7-Tesla magnetic resonance imaging (MRI) and high resolution research tomography (HRRT)-PET fusion system using 18F-FDG. For detailed interregional correlation analysis, 24 subregions of the basal ganglia including pre-commissural dorsal caudate, post-commissural caudate, pre-commissural dorsal putamen, post-commissural putamen, internal globus pallidus, and external globus pallidus and 80 cerebral regions were selected as regions of interest on the MRI image and their glucose metabolism were calculated from the PET images. Pearson's product-moment correlation analysis was conducted for the interregional correlation analysis of the basal ganglia. Functional correlation patterns between the basal ganglia and cerebral cortex were not only consistent with the findings of previous studies, but also showed new functional correlation between the dorsal striatum (i.e., caudate nucleus and putamen) and insula. In this study, we established the detailed basal ganglia subregional functional correlation patterns using 18F-FDG PET/MRI fusion imaging. Our methods and results could potentially be an important resource for investigating basal ganglia dysfunction as well as for conducting functional studies in the context of movement and psychiatric disorders.