DIRECTIONAL CHANGES IN TISSUE REFLECTIVITY MAY INFLUENCE FLOW DETECTION ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Imaging

Background:

• Optical coherence tomography angiography (OCT-A) is crucial for visualizing retinal vasculature.
• The Henle fiber layer (HFL) reflectivity can vary, potentially impacting OCT-A interpretation.
• Understanding factors affecting flow detection is vital for accurate diagnosis.

Purpose of the Study:

• To investigate if directional or anatomical changes in Henle fiber layer (HFL) reflectivity influence flow detection on OCT-A.
• To assess the impact of HFL reflectivity on visualizing superficial and deep capillary plexuses.

Main Methods:

• Cross-sectional analysis of patients undergoing OCT-A.
• Manual manipulation of beam entrance and natural scan tilting in myopic staphylomas were used to alter HFL visualization.
• Comparison of OCT-A flow in areas with and without enhanced HFL reflectivity.

Main Results:

• Enhanced HFL reflectivity did not alter superficial capillary plexus flow.
• Deep capillary plexus flow visualization was affected by altered projection of superficial flow.
• This phenomenon was observed in both manually induced and naturally occurring HFL reflectivity changes.

Conclusions:

• Directional HFL reflectivity changes can alter deep capillary plexus flow detection on OCT-A.
• Altered projection of superficial flow onto deeper layers is the mechanism.
• Clinicians should minimize scan tilting and be aware of this in eyes with posterior staphyloma.