Polarization-multiplexed, dual-beam swept source optical coherence tomography angiography

Area of Science:

• Ophthalmology
• Biomedical Optics
• Medical Imaging

Background:

• Optical Coherence Tomography Angiography (OCTA) is crucial for visualizing retinal vasculature.
• Expanding the Field of View (FOV) in OCTA systems is essential for comprehensive retinal imaging.
• Current OCTA systems often have limitations in FOV, requiring mosaicking of multiple scans.

Purpose of the Study:

• To propose and demonstrate a polarization-multiplexed, dual-beam setup to expand the FOV of a swept-source OCTA system.
• To achieve simultaneous imaging of two distinct retinal areas with a single scan.
• To enable efficient and wider FOV retinal angiography.

Main Methods:

• Utilized a Wollaston prism to split light into two orthogonally polarized beams.
• Introduced a glass plate to create a path length difference, frequency-encoding interferograms.
• Acquired simultaneous 5 × 5 mm² angiograms from two beams with a ~2 mm depth separation.

Main Results:

• Achieved a dual-beam configuration with ~14° angular separation at the cornea, translating to ~4.2 mm retinal separation.
• Successfully obtained two 5 × 5 mm² angiograms simultaneously within 4 seconds.
• Montaged the two angiograms to achieve a significantly expanded FOV of approximately 5 × 9.2 mm².

Conclusions:

• The proposed polarization-multiplexed, dual-beam OCTA system effectively expands the imaging FOV.
• This method allows for simultaneous acquisition of two separate angiograms, improving imaging efficiency.
• The technique offers a promising approach for wider FOV retinal angiography, aiding in the diagnosis of various eye conditions.