Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06661564

Identification of Diagnosis Biomarkers in the Tears of Alzheimer's Disease Patients: The COG-EYE Pilot Study

The diagnosis of Alzheimer's disease (AD) relies on the detection of protein biomarkers, particularly in cerebrospinal fluid (e.g., Aβ and phosphorylated Tau) or through brain imaging. The invasive nature of lumbar puncture and the numerous contraindications have driven the search for early and reliable diagnostic biomarkers for AD.

Human tears are an accessible biological fluid that has proven relevant in the biomarker search strategy for both ophthalmological and systemic diseases, especially neurodegenerative conditions. Advances in methods for low-volume analysis have facilitated the identification of tear biomarkers. Total tau has been reported as elevated in the tears of patients with AD compared to controls (n=65). Additionally, metabo-lipidomic analyses offer several advantages (accessibility, non-invasiveness, reproducibility) and also appear promising as a diagnostic tool for systemic and neurodegenerative diseases, such as amyotrophic lateral sclerosis. This supports the relevance of comparing both AD proteins biomarkers and metabo-lipidomic signatures in the tears of patients with AD (Mild Cognitive Impairement (MCI) and dementia) with healthy controls.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Alzheimer Disease Brain Diseases Central Nervous System Diseases Dementia Lacerations Mental Disorders Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases Tauopathies Wounds and Injuries

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥18 years
  • Participant affiliated in French Social Security scheme
  • Informed and written consent from the participant

Exclusion criteria

  • Pregnant or breastfeeding woman
  • Participant under judicial protection measures
  • Participant under guardianship or curatorship
  • Contraindications to participation in the research:

Other neurodegenerative disease Any eye drops or treatment that may interfere with tear production Occasional or permanent contact lens use within the last 3 months Eye surgery ≤3 months Any ocular pathology other than refractive errors, oculomotor disorders, amblyopia Any general pathology other than AD with ocular implications

-Inability to perform tear collection

Treatment and study plan

Basal tear collection for the analysis of metabo-lipidomic profiles and concentrations of protein biomarkers (Tau, phosphorylated Tau, Aβ 1-40, and Aβ 1-42)

Other

Collection of a tear volume of (i) 2 x 5µL using glass microcapillary tubes and (ii) 12µL using Schirmer strips after the instillation of anesthetic eye drops for metabo-lipidomic analysis and multiplexing of protein markers

Collection of a blood sample (5 mL) for blood biomarkers analysis

Other

Collection of a blood sample (5 mL) for blood biomarkers analysis.

Primary outcomes

  1. Concentration of total Tau proteins in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  2. Concentration of phosphorylated Tau proteins in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  3. Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  4. Concentration of Amyloid β 1-42 in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  5. Lipids in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Lipids in tears of patients with AD vs healthy volunteers

  6. Metabolites in basal tears of patients with AD vs healthy volunteers

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Metabolites in tears of patients with AD vs healthy volunteers

Secondary outcomes

  1. Concentration of total Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  2. Concentration of phosphylated Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: A inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  3. Concentration of Amyloid β 1-40 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: A inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  4. Concentration of Amyloid β 1-42 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: A inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  5. Lipids in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.

  6. Metabolites in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.

  7. Concentration of total Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  8. Concentration of phosphorylated Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  9. Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  10. Concentration of Amyloid β 1-42 proteins in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

  11. Lipids in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.

  12. Metabolites in basal tears of patients with AD-dementia vs patients with AD-MCI

    Time frame: At inclusion

    Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.

Study contacts

Contact information is provided by the study sponsor or research team.

Raoul Kanav KHANNA, MD, PhD

CONTACT

[email protected]

Victoire LEROY, MD

CONTACT

[email protected]

0247477693

Sponsors and collaborators

Lead sponsor

University Hospital, Tours

Other

Registry information

Official study title

Identification de Biomarqueurs Diagnostiques Dans Les Larmes de Patients Atteints de Maladie d'Alzheimer : l'étude Pilote COG-EYE

Acronym: COG-EYE

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Oct 28, 2024
Registry last updated
Oct 7, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.