The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review

IntroductionThe retina is the “window” of the central nervous system. Previous studies discovered that retinal thickness degenerates through the pathological process of the Alzheimer’s disease (AD) continuum. Hippocampal atrophy is one of the typical clinical features and diagnostic criteria of AD....

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Main Authors: Shuntai Chen, Dian Zhang, Honggang Zheng, Tianyu Cao, Kun Xia, Mingwan Su, Qinggang Meng
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-08-01
Series:Frontiers in Aging Neuroscience
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fnagi.2023.1232941/full
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author Shuntai Chen
Dian Zhang
Honggang Zheng
Tianyu Cao
Kun Xia
Mingwan Su
Qinggang Meng
author_facet Shuntai Chen
Dian Zhang
Honggang Zheng
Tianyu Cao
Kun Xia
Mingwan Su
Qinggang Meng
author_sort Shuntai Chen
collection DOAJ
description IntroductionThe retina is the “window” of the central nervous system. Previous studies discovered that retinal thickness degenerates through the pathological process of the Alzheimer’s disease (AD) continuum. Hippocampal atrophy is one of the typical clinical features and diagnostic criteria of AD. Former studies have described retinal thinning in normal aging subjects and AD patients, yet the association between retinal thickness and hippocampal atrophy in AD is unclear. The optical coherence tomography (OCT) technique has access the non-invasive to retinal images and magnetic resonance imaging can outline the volume of the hippocampus. Thus, we aim to quantify the correlation between these two parameters to identify whether the retina can be a new biomarker for early AD detection.MethodsWe systematically searched the PubMed, Embase, and Web of Science databases from inception to May 2023 for studies investigating the correlation between retinal thickness and hippocampal volume. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used to assess the study quality. Pooled correlation coefficient r values were combined after Fisher’s Z transformation. Moderator effects were detected through subgroup analysis and the meta-regression method.ResultsOf the 1,596 citations initially identified, we excluded 1,062 studies after screening the titles and abstract (animal models, n = 99; irrelevant literature, n = 963). Twelve studies met the inclusion criteria, among which three studies were excluded due to unextractable data. Nine studies were eligible for this meta-analysis. A positive moderate correlation between the retinal thickness was discovered in all participants of with AD, mild cognitive impairment (MCI), and normal controls (NC) (r = 0.3469, 95% CI: 0.2490–0.4377, I2 = 5.0%), which was significantly higher than that of the AD group (r = 0.1209, 95% CI:0.0905–0.1510, I2 = 0.0%) (p < 0.05). Among different layers, the peripapillary retinal nerve fiber layer (pRNFL) indicated a moderate positive correlation with hippocampal volume (r = 0.1209, 95% CI:0.0905–0.1510, I2 = 0.0%). The retinal pigmented epithelium (RPE) was also positively correlated [r = 0.1421, 95% CI:(−0.0447–0.3192), I2 = 84.1%]. The retinal layers and participants were the main overall heterogeneity sources. Correlation in the bilateral hemisphere did not show a significant difference.ConclusionThe correlation between RNFL thickness and hippocampal volume is more predominant in both NC and AD groups than other layers. Whole retinal thickness is positively correlated to hippocampal volume not only in AD continuum, especially in MCI, but also in NC.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, CRD42022328088.
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spelling doaj.art-21af420d9fab4da38537aac96581168d2023-08-23T15:55:46ZengFrontiers Media S.A.Frontiers in Aging Neuroscience1663-43652023-08-011510.3389/fnagi.2023.12329411232941The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic reviewShuntai Chen0Dian Zhang1Honggang Zheng2Tianyu Cao3Kun Xia4Mingwan Su5Qinggang Meng6School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, ChinaDepartment of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, ChinaDepartment of Oncology, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, ChinaDepartment of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, ChinaDepartment of Respiratory, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, ChinaDepartment of Respiratory, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, ChinaSchool of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, ChinaIntroductionThe retina is the “window” of the central nervous system. Previous studies discovered that retinal thickness degenerates through the pathological process of the Alzheimer’s disease (AD) continuum. Hippocampal atrophy is one of the typical clinical features and diagnostic criteria of AD. Former studies have described retinal thinning in normal aging subjects and AD patients, yet the association between retinal thickness and hippocampal atrophy in AD is unclear. The optical coherence tomography (OCT) technique has access the non-invasive to retinal images and magnetic resonance imaging can outline the volume of the hippocampus. Thus, we aim to quantify the correlation between these two parameters to identify whether the retina can be a new biomarker for early AD detection.MethodsWe systematically searched the PubMed, Embase, and Web of Science databases from inception to May 2023 for studies investigating the correlation between retinal thickness and hippocampal volume. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used to assess the study quality. Pooled correlation coefficient r values were combined after Fisher’s Z transformation. Moderator effects were detected through subgroup analysis and the meta-regression method.ResultsOf the 1,596 citations initially identified, we excluded 1,062 studies after screening the titles and abstract (animal models, n = 99; irrelevant literature, n = 963). Twelve studies met the inclusion criteria, among which three studies were excluded due to unextractable data. Nine studies were eligible for this meta-analysis. A positive moderate correlation between the retinal thickness was discovered in all participants of with AD, mild cognitive impairment (MCI), and normal controls (NC) (r = 0.3469, 95% CI: 0.2490–0.4377, I2 = 5.0%), which was significantly higher than that of the AD group (r = 0.1209, 95% CI:0.0905–0.1510, I2 = 0.0%) (p < 0.05). Among different layers, the peripapillary retinal nerve fiber layer (pRNFL) indicated a moderate positive correlation with hippocampal volume (r = 0.1209, 95% CI:0.0905–0.1510, I2 = 0.0%). The retinal pigmented epithelium (RPE) was also positively correlated [r = 0.1421, 95% CI:(−0.0447–0.3192), I2 = 84.1%]. The retinal layers and participants were the main overall heterogeneity sources. Correlation in the bilateral hemisphere did not show a significant difference.ConclusionThe correlation between RNFL thickness and hippocampal volume is more predominant in both NC and AD groups than other layers. Whole retinal thickness is positively correlated to hippocampal volume not only in AD continuum, especially in MCI, but also in NC.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, CRD42022328088.https://www.frontiersin.org/articles/10.3389/fnagi.2023.1232941/fullAlzheimer’s diseaseOCThippocampusretinaMRI
spellingShingle Shuntai Chen
Dian Zhang
Honggang Zheng
Tianyu Cao
Kun Xia
Mingwan Su
Qinggang Meng
The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
Frontiers in Aging Neuroscience
Alzheimer’s disease
OCT
hippocampus
retina
MRI
title The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
title_full The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
title_fullStr The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
title_full_unstemmed The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
title_short The association between retina thinning and hippocampal atrophy in Alzheimer’s disease and mild cognitive impairment: a meta-analysis and systematic review
title_sort association between retina thinning and hippocampal atrophy in alzheimer s disease and mild cognitive impairment a meta analysis and systematic review
topic Alzheimer’s disease
OCT
hippocampus
retina
MRI
url https://www.frontiersin.org/articles/10.3389/fnagi.2023.1232941/full
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