Three-dimensional segmentation and depth-encoded visualization of choroidal vasculature using swept-source optical...

Area of Science:

• Ophthalmology and Vision Science
• Medical Imaging Technology
• Vascular Biology

Background:

• The choroid is vital for retinal health, and its dysfunction causes major vision loss.
• Pachychoroid diseases, including central serous chorioretinopathy, significantly impact vision.
• Current imaging methods have limitations in visualizing the full choroidal structure.

Purpose of the Study:

• To introduce and evaluate a depth-resolved swept-source optical coherence tomography (SS-OCT) technique.
• To achieve full-thickness, three-dimensional (3D) visualization of choroidal anatomy and vasculature.
• To assess the technique's utility in characterizing topographical features of choroidal vessels in pachychoroid disease.

Main Methods:

• Utilized 15 mm × 9 mm volume scans centered on the fovea using SS-OCT.
• Developed an automated method to segment choroidal vessels based on their hyporeflective lumens.
• Rendered binarized vessels in a 3D viewer, color depth-encoded them, and compared with indocyanine green angiography (ICGA).

Main Results:

• The SS-OCT technique provided detailed 3D visualization of the choroidal vascular network.
• En face SS-OCT projections of major vessels closely resembled ICGA findings.
• SS-OCT revealed additional depth-encoded 3D information and clinically relevant structural details (thickness, vessel depth) not visible with ICGA in 16 eyes with pachychoroid disease.

Conclusions:

• The developed SS-OCT technique advances in vivo visualization of the full-thickness choroid.
• It effectively reveals topographical features of choroidal vasculature, offering potential for quantitative analysis.
• This improved visualization provides new insights into choroid-related disease mechanisms and treatment responses.