High-penetration swept source Doppler optical coherence angiography by fully numerical phase stabilization.

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Deep choroidal vasculature imaging is crucial for diagnosing various eye diseases.
• Current imaging techniques may lack penetration depth or require complex hardware.
• Optical Coherence Tomography (OCT) offers high-resolution cross-sectional imaging.

Purpose of the Study:

• To develop and validate a high-penetration swept-source OCT (HP-SS-OCT) system for deep choroidal imaging.
• To implement a novel, hardware-independent numerical phase stabilization algorithm for Doppler OCT.
• To demonstrate the capability of imaging bidirectional blood flow in the deep choroid.

Main Methods:

• Development of an HP-SS-OCT system utilizing a 1-μm short cavity laser.
• Application of Doppler OCT processing with a custom numerical phase stabilization algorithm.
• Utilizing two distinct Doppler modes with varying time intervals for bidirectional flow analysis.
• Comparison of en face projection images with Indocyanine Green Angiography (ICGA).

Main Results:

• Successful imaging of bidirectional blood flow and vasculature in the deep choroid.
• The numerical phase stabilization method proved simple and effective, requiring no additional calibration hardware.
• The HP-SS-OCT system demonstrated utility comparable to ICGA for visualizing choroidal vasculature.
• The developed system is adaptable for various SS-OCT applications.

Conclusions:

• The novel HP-SS-OCT system with numerical phase stabilization provides effective deep choroidal vasculature imaging.
• The hardware-independent stabilization method simplifies Doppler OCT implementation across different systems.
• This technology holds promise for enhanced diagnosis and monitoring of ocular pathologies affecting the choroid.