Iris Color and Day-Night Changes in the Sympathovagal Ratio

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.

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Key information

Conditions

Iris Diseases Eye Diseases Uveal Diseases

Age range

16 year–50 year

Sex eligibility

All sexes

Study type

Observational

About this study

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].

Who can participate

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

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.

Treatment and study plan

Iris Color Measurement , LF/HF Measurement

Other

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)

Primary outcomes

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.

Sponsors and collaborators

Lead sponsor

Ankara Ataturk Sanatorium Training and Research Hospital

Other Gov

Registry information

Important dates

Study start: 2016
Primary completion: 2022
Study completion: 2022
First posted: Mar 8, 2023
Registry last updated: Mar 9, 2023

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.

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Completed