Choriocapillaris Imaging Using Multiple En Face Optical Coherence Tomography Angiography Image Averaging

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Vasculature

Background:

• In vivo imaging of the choriocapillaris presents significant technological challenges.
• Optical coherence tomography angiography (OCTA) offers potential for improved choriocapillaris imaging.

Purpose of the Study:

• To evaluate the impact of multiple en face image averaging on OCTA imaging of the choriocapillaris.
• To assess if averaging improves the visualization of retinal vasculature.

Main Methods:

• 17 healthy participants underwent OCTA imaging of a 3x3 mm macular area.
• Nine OCTA cube scan sets were acquired per eye and registered.
• Choriocapillaris images were averaged, and quantitative parameters were compared to unaveraged images.

Main Results:

• Averaged OCTA images revealed a clear meshwork appearance compared to granular unaveraged images.
• Averaging increased flow voids (P<.001) and vessel density (P<.001).
• Averaged images showed smaller average flow void size (P<.001) and more homogeneous void distribution.

Conclusions:

• Multiple en face averaging significantly improves the visualization of the choriocapillaris on OCTA.
• This technique transforms granular images into a resolved vascular network in healthy volunteers.
• Averaging enhances the ability to discern intervascular spaces in OCTA imaging.