Iris Color and Day-Night Changes in the Sympathovagal Ratio

March 7, 2023 updated by: Şahbender Koç, Ankara Ataturk Sanatorium Training and Research Hospital
Iris melanocytes are innervated by parasympathetic and sympathetic nerve endings. Light affects autonomic nervous system activity via the retino-hypothalamic pathway. The hypothesis that the day-to-night variations in the sympatovagal ratio (LF/HF) may differ among individuals with different brown iris patterns was tested.

Study Overview

Status

Status

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

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.

Detailed Description

A total of 621 healthy adults, aged between 16 and 50, with brown eyes and not diagnosed with a disease that might affect the autonomous nerve system were included in the study. A digital camera was used to acquire iris photos. Subjects were grouped into iris color groups (2-0 bg, 1-0 bg, 1-1 db, 1-1 lb, 2-0 b, and 1-0 b). Iris photos were analyzed with Picture Color Analyzer RBG software. The Central/Peripheral (R/RGB) ratio was used for objective distinction between the groups. Using 24-h Holter ECG monitoring, the change in the sympathovagal ratio from day (between 07:00 and 23:00 hrs) to night (between 23:00 and 07:00 hrs) was determined with the formula [(Day - Night) LF/HF)/Day LF/HF].

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.
Observational

Enrollment (Actual)

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.
621

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

16 years to 50 years (Child, Adult)

Accepts Healthy Volunteers

N/A

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

A total of 650 healthy individuals between the ages of 16 and 50 who applied for cardiac examination and had normal findings were recruited for the study.

Description

Inclusion Criteria:

A total of 650 healthy individuals between the ages of 16 and 50 .

Exclusion Criteria:

Diseases that could affect the autonomic nervous system; Obesity Obstructive sleep apnea syndrome Hypertension Diabetes mellitus Atrial fibrillation Coronary disease Heart failure Goiter, etc.

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
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.
2-0 darkbown-green (2-0 bg)
Those with distinctively dark brown in the central area, slightly green in the peripheral area,
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
1-0 lightbrown-green (1-0 bg).
Those with slightly dark brown in the central area and green in the peripheral area,
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
dark brown (1-1 db)
Eyes with the same color structure in the central iris and the peripheral iris.
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
light brown (1-1 lb)
Eyes with the same color structure in the central iris and the peripheral iris.
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
dark brown (2-0 b)
Those with distinctively dark brown in the central iris area compared to the periphery .
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)
slightly dark brown (1-0 b)
Those with slightly dark brown (1-0 b) in the central iris area compared to the periphery .
Other: Iris Color Measurement , LF/HF Measurement
Iris Color Measurement (Photos were taken of the iris with a digital camera ) LF/ HF Measurement (Using the three-channel standard ambulatory Holter recording system)

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
Measure Description
Time Frame
LF/HF ratio
Time Frame: one week
low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, 0.16-0.4 Hz) measurements were taken from day and night changes in the heart rate by using the frequency-domain analysis method.
one week

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.
Ankara Ataturk Sanatorium Training and Research Hospital

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.
May 5, 2016

Primary Completion (Actual)

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.
May 5, 2022

Study Completion (Actual)

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.
June 1, 2022

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).
February 27, 2023

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.
February 27, 2023

First Posted (Actual)

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.
March 8, 2023

Study Record Updates

Last Update Posted (Estimate)

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.
March 9, 2023

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.
March 7, 2023

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.
March 1, 2023

More Information

Terms related to this study

Keywords

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.
  • 1099/9.3.2016

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