A novel electrocardiogram-synchronized laser Doppler holography system for cardiac cycle-resolved retinal...

Area of Science:

• Ophthalmology
• Cardiovascular Physiology
• Biomedical Engineering

Background:

• The retinal microvasculature offers a direct, non-invasive view of microcirculation, crucial for assessing ocular and systemic health.
• Current methods lack high-speed, cardiac-resolved assessment of retinal hemodynamics.

Purpose of the Study:

• To develop and validate a novel imaging platform integrating electrocardiography (ECG) with laser Doppler holography (LDH).
• To enable real-time, cardiac cycle-resolved assessment of retinal hemodynamics.
• To establish a quantitative framework for studying the eye-heart relationship.

Main Methods:

• Integration of a custom one-lead ECG with high-speed laser Doppler holography (LDH).
• Imaging of 25 healthy adults, capturing 563 cardiac cycles with <5 ms system latency.
• Measurement of ECG-retina latencies (R-PSV, R-MaxSlope, R-PSV½).

Main Results:

• LDH-derived beat-to-beat intervals closely tracked ECG R-R intervals with minimal differences (~3 ms).
• The R-PSV½ latency demonstrated highest repeatability (ICC=0.78, median CV=4.8%).
• Exploratory analyses showed moderate associations between ECG-retina latencies, age, and heart rate.

Conclusions:

• The integrated ECG-LDH platform provides repeatable, synchronized, high-speed, cardiac-resolved retinal hemodynamic measurements.
• This system establishes a quantitative framework for investigating the eye-heart relationship.
• The technology holds potential for early detection and monitoring of cardiovascular-related ocular conditions.