title: The Association Between Retinal Neuronal Layer and Brain Structure is Disrupted in Patients with Cognitive Impairment and Alzheimer's Disease.
abstract: Both healthy and pathological aging due to Alzheimer's disease (AD) are associated with decreased brain grey matter volume (GMV) and disrupted white matter (WM) microstructure. Thinner macular ganglion cell-inner plexiform layer (GC-IPL) measured by spectral-domain optical coherence tomography has been reported in patients with AD and mild cognitive impairment. Emerging evidence suggested a link between thinner GC-IPL and lower GMV in subjects with no dementia using region-of-interest-based approach. However, it remains unknown whether GC-IPL thickness is associated with brain WM microstructure and how such association differed between normal and cognitively impaired subjects. Here, for subjects with no cognitive impairment (NCI), thinner GC-IPL was associated with lower WM microstructure integrity in the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, corticospinal tracts, anterior thalamic radiation, and cingulum regions, while it was weakly associated with lower GMV in visual cortex and cerebellum. Nevertheless, these retina-brain associations were disrupted in the presence of cognitive impairment. Correlations between GMV and GC-IPL were lost in patients with cognitive impairment but no dementia (CIND) and AD patients. GC-IPL was related to WM microstructural disruption in similar regions with decreased significance. In contrast, lower WM microstructure integrity in the fornix showed a trend of correlation with thinner GC-IPL in both CIND and AD but not NCI. Collectively, our findings suggest the possible physiological retina-brain relationship in healthy aging, which might be disrupted by disease-induced changes in patients with cognitive impairment. Longitudinal study with larger patient sample should follow to confirm the disease mechanism behind these retina-brain relationship changes.
authors: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore.
authors: Siwei
authors: S
authors: Liu
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
authors: Yi-Ting
authors: YT
authors: Ong
authors: Department of Pharmacology, National University of Singapore, Singapore.|Memory Aging & Cognition Centre, National University Health System, Singapore.
authors: Saima
authors: S
authors: Hilal
authors: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore.
authors: Yng Miin
authors: YM
authors: Loke
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
authors: Tien Y
authors: TY
authors: Wong
authors: Department of Pharmacology, National University of Singapore, Singapore.|Memory Aging & Cognition Centre, National University Health System, Singapore.
authors: Christopher Li-Hsian
authors: CL
authors: Chen
authors: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.|Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors: Carol Y
authors: CY
authors: Cheung
authors: Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Medical School, Singapore.|Clinical Imaging Research Centre, The Agency for Science, Technology and Research and National University of Singapore, Singapore.
authors: Juan
authors: J
authors: Zhou
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000523:psychology; D001921:Brain / Q000000981:diagnostic imaging*; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012165:Retinal Ganglion Cells / Q000473:pathology; D055351:Retinal Neurons / Q000473:pathology*
keywords: Alzheimer disease; diffusion tensor imaging; mild cognitive impairment; optical coherence tomography; retinal ganglion cells; white matter