Clinical trial NCT05655793: The TearAD Study: Tear Biomarkers for Alzheimer's Disease (AD) Screening and Diagnosis
Official title: The TearAD Study: Tear Biomarkers for Alzheimer's Disease (AD) Screening and Diagnosis
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Alzheimer Disease
Keywords: Tear Fluid
Retinal imaging
Biomarkers
Lead sponsor: Maastricht University Medical Center
Sponsor class: OTHER
First posted: 2022-12-19
Enrollment: 200
Sex: ALL
Minimum age (years): 50
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: The patients will be selected from the population that visit the memory clinic and are willing to participate in scientific research.

Brief summary: The goal of this observational longitudinal study is to investigates whether tear fluid is a non-invasive source of biomarkers for Alzheimer's disease. The main aim of the study is to evaluate diagnostic accuracy measures (sensitivity and specificity) of tear and retinal biomarkers to discriminate individuals with and without neurodegeneration.

Tear fluid from participants will be collected non-invasively with Schirmer's strips, which is a small paper strip placed in the lower eye lid for a maximum of 5 minutes. Additionally, standard, ultra-wide field and cross-sectional retinal images will be obtained.


Eligibility criteria: Inclusion Criteria (healthy controls):

* Available CSF, PET, CT or MRI data to evaluate the presence/absence of neurodegeneration (preferably within 1 year of inclusion in this study)
* Absence of cognitive complaints or treatment and did not seek help for cognitive complaints in the past
* MMSE score 26-30 at baseline
* Age \> 50 years
* Available for follow-up (up to 24 months)
* Written informed consent obtained and documented

Inclusion criteria (patients):

* Available CSF, PET, CT or MRI data to evaluate the presence/absence of neurodegeneration (preferably within 1 year of inclusion in this study)
* Available for follow-up (up to 24 months)
* Written informed consent obtained and documented
* Capable of giving informed consent themselves (MMSE score \> 17/30)

Exclusion Criteria (all subjects):

* Ocular conditions that could influence tear biochemical parameters (including eye infection, eye inflammation, eye surgery within the last 28 days or other acute eye conditions)
* Neurological or systemic chronic conditions known to interfere with retinal thickness (e.g., glaucoma, diabetes mellitus)
* Ocular conditions interfering with optical coherence tomography (OCT) quality/retinal thickness: e.g. severe cataract, age-related macular degeneration, and glaucoma

Primary outcomes:
measure: Capability of tear biomarkers to discriminate individuals with neurodegeneration from those without neurodegeneration and assess the change in biomarker levels over time.
timeFrame: Sampling done at t= 0, 1 and 2 years.
Secondary outcomes:
measure: The difference in tear biomarker level between patients and controls, and between patient groups and how these differences change over time.
timeFrame: Sampling done at t= 0, 1 and 2 years.
measure: Correlation of biomarker levels in tears, blood and cerebral spinal fluid (CSF).
timeFrame: Baseline measurements (t=0) will be used to determine correlation.
measure: Correlation between tear biomarkers and other ocular imaging biomarkers, as well as assessing the change of this correlation over time.
timeFrame: Imaging done at t= 0, 1 and 2 years.
Other outcomes:
Locations:
city: Maastricht
country: Netherlands
facility: Academic Hospital Maastricht
state: Limburg
city: Amsterdam
country: Netherlands
facility: Amsterdam University Medical Center
state: Noord-Holland
Study officials:
affiliation: Maastricht University Medical Center
name: Marlies Gijs, PhD
role: PRINCIPAL_INVESTIGATOR
References: