{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T13:31:23Z","timestamp":1792071083705,"version":"4.4.0"},"reference-count":30,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,30]],"date-time":"2023-01-30T00:00:00Z","timestamp":1675036800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sapienza University of Rome","award":["RG11916B795679B7\/2019"],"award-info":[{"award-number":["RG11916B795679B7\/2019"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>We aimed to evaluate the diagnostic role of Alzheimer\u2019s disease (AD) biomarkers in tears as well as their association with retinal and choroidal microstructures. In a cross-sectional study, 35 subjects (age 71.7 \u00b1 6.9 years) were included: 11 with prodromal AD (MCI), 10 with mild-to-moderate AD, and 14 healthy controls. The diagnosis of AD and MCI was confirmed according to a complete neuropsychological evaluation and PET or MRI imaging. After tear sample collection, \u03b2-amyloid peptide A\u03b21-42 concentration was analyzed using ELISA, whereas C-terminal fragments of the amyloid precursor protein (APP-CTF) and phosphorylated tau (p-tau) were assessed by Western blot. Retinal layers and choroidal thickness (CT) were acquired by spectral-domain optical coherence tomography (SD-OCT). A\u03b21-42 levels in tears were able to detect both MCI and AD patients with a specificity of 93% and a sensitivity of 81% (AUC = 0.91). Tear levels of A\u03b21-42 were lower, both in the MCI (p &lt; 0.01) and in the AD group (p &lt; 0.001) when compared to healthy controls. Further, A\u03b21-42 was correlated with psychometric scores (p &lt; 0.001) and CT (p &lt; 0.01). CT was thinner in the affected patients (p = 0.035). No differences were observed for APP-CTF and p-tau relative abundance in tears. Testing A\u03b21-42 levels in tears seems to be a minimally invasive, cost-saving method for early detection and diagnosis of AD.<\/jats:p>","DOI":"10.3390\/ijms24032590","type":"journal-article","created":{"date-parts":[[2023,1,30]],"date-time":"2023-01-30T04:58:25Z","timestamp":1675054705000},"page":"2590","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Beta-Amyloid Peptide in Tears: An Early Diagnostic Marker of Alzheimer\u2019s Disease Correlated with Choroidal Thickness"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4991-9689","authenticated-orcid":false,"given":"Magda","family":"Gharbiya","sequence":"first","affiliation":[{"name":"Department of Sense Organs, Sapienza University of Rome, 155, Viale del Policlinico, 00161 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6152-433X","authenticated-orcid":false,"given":"Giacomo","family":"Visioli","sequence":"additional","affiliation":[{"name":"Department of Sense Organs, Sapienza University of Rome, 155, Viale del Policlinico, 00161 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alessandro","family":"Trebbastoni","sequence":"additional","affiliation":[{"name":"Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7562-9274","authenticated-orcid":false,"given":"Giuseppe Maria","family":"Albanese","sequence":"additional","affiliation":[{"name":"Department of Sense Organs, Sapienza University of Rome, 155, Viale del Policlinico, 00161 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3353-8918","authenticated-orcid":false,"given":"Mayra","family":"Colardo","sequence":"additional","affiliation":[{"name":"Department of Biosciences and Territory, University of Molise, 86100 Campobasso, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabrizia","family":"D\u2019Antonio","sequence":"additional","affiliation":[{"name":"Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0465-9470","authenticated-orcid":false,"given":"Marco","family":"Segatto","sequence":"additional","affiliation":[{"name":"Department of Biosciences and Territory, University of Molise, 86100 Campobasso, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8974-991X","authenticated-orcid":false,"given":"Alessandro","family":"Lambiase","sequence":"additional","affiliation":[{"name":"Department of Sense Organs, Sapienza University of Rome, 155, Viale del Policlinico, 00161 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"518","DOI":"10.2174\/1567205016666190517121140","article-title":"Biomarkers for Alzheimer\u2019s Disease","volume":"16","author":"Maccioni","year":"2019","journal-title":"Curr. 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Opt."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/24\/3\/2590\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:19:30Z","timestamp":1760120370000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/24\/3\/2590"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,30]]},"references-count":30,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["ijms24032590"],"URL":"https:\/\/doi.org\/10.3390\/ijms24032590","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,30]]}}}