Detailed Vascular Anatomy of the Human Retina by Projection-Resolved Optical Coherence Tomography Angiography

Area of Science:

• Ophthalmology
• Medical Imaging
• Vascular Biology

Background:

• Optical coherence tomography angiography (OCTA) is a noninvasive 3D imaging technique for retinal and choroidal circulations.
• A key limitation of OCTA is the artifactual projection of superficial vascular signals onto deeper retinal layers, hindering depth discrimination.
• Existing methods struggle to accurately differentiate vascular layers in 3D retinal imaging.

Purpose of the Study:

• To introduce and validate the projection-resolved (PR) OCTA algorithm for improved depth resolution in retinal imaging.
• To investigate the detailed 3D architecture of normal human retinal vasculature in vivo.
• To propose an updated nomenclature and segmentation framework for retinal vascular anatomy based on novel findings.

Main Methods:

• Development and application of the projection-resolved (PR) OCTA algorithm to remove projection artifacts.
• In vivo imaging of the retinal vasculature in normal human volunteers.
• Analysis of vascular patterns and plexuses in relation to anatomical landmarks like the optic disc and fovea.

Main Results:

• PR-OCTA successfully improved depth resolution, enabling clearer visualization of deeper retinal vessels.
• The study identified 2 to 4 distinct vascular plexuses within the retina, varying by location.
• Observed vascular patterns and interconnections align with established histological findings, validating the imaging approach.

Conclusions:

• PR-OCTA is a powerful tool for high-resolution, in vivo 3D imaging of retinal vasculature.
• The findings support a revised understanding of retinal vascular architecture, with implications for nomenclature and segmentation.
• This technology provides a foundation for future research into retinal vascular diseases and abnormalities.