Relative retinal flow velocity detection using optical coherence tomography angiography imaging.

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Optical coherence tomography angiography (OCTA) provides detailed retinal vasculature visualization.
• Conventional OCTA protocols have limitations in dynamic range and velocity-intensity correlation due to long scan intervals.
• Distinguishing between fast and slow retinal blood flow is crucial for diagnosing early-stage retinal diseases like vein occlusion.

Purpose of the Study:

• To develop and validate a method for detecting relative blood flow velocity in the human retina using spectral-domain OCTA.
• To overcome the limitations of conventional OCTA in assessing flow dynamics.
• To enhance the diagnostic capabilities of OCTA for retinal vascular conditions.

Main Methods:

• Utilized a 67.5 kHz spectral-domain OCTA device.
• Adapted A-scan time-intervals within a single OCTA acquisition to expand the detectable velocity range.
• Combined resulting OCTA images and validated the method with microchannel flow experiments.

Main Results:

• Successfully demonstrated a method to detect relative flow velocity in the human retina.
• Expanded the detectable velocity range of OCTA by modifying scan acquisition parameters.
• Validated the quantitative accuracy of the method through controlled flow experiments.

Conclusions:

• The developed OCTA method enables the detection of relative retinal blood flow velocity.
• This approach improves the dynamic range and velocity correlation of OCTA imaging.
• The technique shows promise for the early assessment of retinal diseases by analyzing blood flow dynamics.