Retinal Neuro-vascular Coupling in Patients With Neurodegenerative Disease

April 6, 2022 updated by: Gerhard Garhofer, Medical University of Vienna
Alzheimer´s disease (AD) in one of the most important causes of dementia and poses a considerable challenge in health care. Today, criteria for the diagnosis and the follow up of patients with AD mainly rely either on subjective tests or invasive methods. This limits the general applicability of the latter test for population screening and underlines the need for the identification of easily accessible tools for the identification of high-risk subjects. Because of its unique optical properties, the eye offers the possibility of the non-invasive assessment of both structural and functional alterations in neuronal tissue. As the neuro-retina is part of the brain, it does not come as a surprise that neuro-degenerative changes in the brain are accompanied by structural and possibly also functional changes in the neuro-retina and the ocular vasculature. The current study seeks to test the hypothesis that beside the known anatomical changes, also functional changes can be detected in the retina of patients with AD. For this purpose, flicker light induced hyperemia will be measured in the retina as a functional test to assess the coupling between neural activity and blood flow. Further, structural parameters such as retinal nerve fiber layer thickness and function parameters such as ocular blood flow and retinal oxygenation will be assessed and compared to age and sex matched controls.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Austria
      • Vienna, Austria, 1090
        • Recruiting
        • Department of Clinical Pharmacology, Medical University of Vienna
        • Principal Investigator:
          • Gerhard Garhöfer, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

50 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

Inclusion criteria for healthy subjects

  • Men and women aged over 50 years
  • Non-smokers
  • Normal findings in the medical history unless the investigator considers an abnormality to be clinically irrelevant
  • Normal ophthalmic findings, ametropia < 6 Dpt

Inclusion criteria for patients with AD:

  • Men and women aged over 50 years
  • Normal ophthalmic findings, ametropia < 6 Dpt.

  • Confirmed diagnosis of probable AD of mild to moderate degree defined as:

    1. Diagnosis of probable Alzheimer's disease based on the NINCDS/ADRDA criteria
    2. Assessing the severity of Alzheimer's disease of mild to moderate degree by the Mini Mental State Examination (MMSE). AD of mild to moderate degree has been confirmed if the MMSE score is in the range of 20 to 26 inclusive
  • Hachinski Ischemia Scale is used to try and distinguish AD from multi-infarct dementia. A score of ≤ 4 suggests AD Informed consent capability
  • Adequate visual and auditory acuity to allow neuropsychological testing and participation in the ocular blood flow measurements
  • A potential participant has to be on stable doses of all medications he/she is taking because of consisting illnesses according to medical history (except AD therapy itself which will be recorded separately) for at least 30 days prior inclusion, if considered relevant by the investigator.

Inclusion criteria for patients with mild cognitive impairment:

  • Men and women aged over 50 years
  • Normal ophthalmic findings, ametropia < 6 Dpt.

  • Diagnosis of probable mild cognitive impairment (MCI) defined as:

    1. memory complaint, corroborated by an informant
    2. abnormal memory function, documented by delayed recall of one paragraph from the Logical Memory II subtest of the Wechsler Memory Scale-Revised (cutoff scores: ≤8 for ≥16 years of education; ≤4 for 8 to 15 years of education; and ≤2 for 0 to 7 years of education [the maximum number of paragraph items possible to correctly recall is 25])
    3. normal general cognitive function, as determined by a clinician's judgment based on a structured interview with the patient and an informant (Clinical Dementia Rating [CDR]) and a Mini-Mental State Examination (MMSE) score greater than 26
    4. no or minimal impairment in activities of daily living (ADLs), as determined by a clinical interview with the patient and informant
    5. not sufficiently impaired, cognitively and functionally, to meet the NINCDS/ADRDA criteria, as judged by an experienced AD research clinician
  • Hachinski Ischemia Scale is used to try and distinguish MCI from multi-infarct dementia. A score of ≤ 4 suggests MCI Informed consent capability
  • Adequate visual and auditory acuity to allow neuropsychological testing and participation in the ocular blood flow measurements
  • A potential participant has to be on stable doses of all medications he/she is taking because of consisting illnesses according to medical for at least 30 days prior inclusion, if considered relevant by the investigator.

Exclusion Criteria for patients:

  • Presence or history of a severe medical condition other than cognitive impairment as judged by the clinical investigator
  • Untreated Arterial hypertension
  • History or family history of epilepsy
  • Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator
  • Best corrected visual acuity < 0.5 Snellen
  • Ametropia greater than 6 Dpt
  • pregnancy or planned pregnancy
  • Major psychiatric disorder (e.g. schizophrenia), if considered relevant by the investigator
  • Significant neurological disease other than AD or MCI, if considered relevant by the investigator
  • Alcoholism or substance abuse

Exclusion criteria for healthy volunteers:

  • Presence or history of a severe medical condition as judged by the clinical investigator
  • Untreated Arterial hypertension
  • History or family history of epilepsy
  • Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator
  • Family history of AD
  • Best corrected visual acuity < 0.5 Snellen
  • Ametropia 6 Dpt
  • Pregnancy or planned pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Healthy
Healthy volunteers
Device: Optical Coherence Tomography
Device: DVA
Other Names:
  • Dynamic Vessel Analyzer
Device: FDOCT
Other Names:
  • Fourier Domain Color Doppler Optical Coherence Tomography
Device: Pattern ERG
Experimental: Mild cognitive impairment
Patients with mild cognitive impairment
Device: Optical Coherence Tomography
Device: DVA
Other Names:
  • Dynamic Vessel Analyzer
Device: FDOCT
Other Names:
  • Fourier Domain Color Doppler Optical Coherence Tomography
Device: Pattern ERG
Experimental: Alzheimer Disease
Patients with Alzheimer Disease
Device: Optical Coherence Tomography
Device: DVA
Other Names:
  • Dynamic Vessel Analyzer
Device: FDOCT
Other Names:
  • Fourier Domain Color Doppler Optical Coherence Tomography
Device: Pattern ERG

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Flicker induced increase in retinal blood flow
Time Frame: 1 day
1 day

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Medical University of Vienna

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 27, 2016

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2023

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 21, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 21, 2016

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 26, 2016

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 7, 2022

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 6, 2022

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2022

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • OPHT-180515

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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