NCT05759715

Iris Color and Day-Night Changes in the Sympathovagal Ratio

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 621 (actual)
• Sponsor: Ankara Ataturk Sanatorium Training and Research Hospital · Other Government
• Sex: All
• Age: 16 Years – 50 Years
• Healthy volunteers: —

Summary

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.

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 \[(Day - Night) LF/HF)/Day LF/HF\].

Conditions

• Iris Diseases

Interventions

Type	Name	Description
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)

Timeline

• Start date: 2016-05-05
• Primary completion: 2022-05-05
• Completion: 2022-06-01
• First posted: 2023-03-08
• Last updated: 2023-03-09