Repeatability and Reproducibility of Total Retinal Blood Flow Measurements Using Bi-Directional Doppler OCT

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Accurate measurement of retinal blood flow is crucial for diagnosing and monitoring vascular eye diseases.
• Optical coherence tomography (OCT) is a non-invasive imaging technique that can be adapted for blood flow assessment.

Purpose of the Study:

• To evaluate the repeatability and reproducibility of total retinal blood flow measurements.
• To compare a novel algorithm with a conventional approach for calculating blood velocities using dual-beam Doppler OCT.

Main Methods:

• Utilized a custom-built dual-beam bidirectional Doppler OCT system.
• Assessed repeatability (n=10) and reproducibility (n=34) in healthy subjects.
• Compared two analysis approaches for calculating absolute blood velocities (Q_A,abs, Q_V,abs vs. Q_A,new, Q_V,new).

Main Results:

• The novel algorithm (Q_A,new, Q_V,new) demonstrated superior repeatability (ICCs 0.91-0.93) and reproducibility (ICCs 0.87-0.91) compared to the conventional approach (ICCs 0.78-0.84).
• Excellent agreement was found between retinal artery and vein blood flow measurements.
• Dual-beam Doppler OCT showed high reliability for total retinal blood flow assessment.

Conclusions:

• Dual-beam Doppler OCT provides highly reproducible measurements of total retinal blood flow.
• A novel algorithm significantly improves the accuracy and reliability of these measurements.
• This technique holds promise for longitudinal studies and as a biomarker for vascular eye disease progression.