Retinal Vessel Coronal Displacement in Intermediate Age-Related Macular Degeneration.

Area of Science:

• Ophthalmology
• Medical Imaging
• Biomedical Engineering

Background:

• Intermediate age-related macular degeneration (iAMD) is a leading cause of vision loss.
• Understanding microvascular changes in iAMD is crucial for developing effective treatments.
• Current methods for quantifying microvascular changes in iAMD are limited.

Purpose of the Study:

• To assess the feasibility of a novel vectorial image analysis method for quantifying coronal microvascular displacement.
• To measure microvascular displacement in different retinal plexuses (SCP, DCP, CC) over 6 months in iAMD patients.
• To investigate the association between specific iAMD features (RPD, drusenoid PED) and microvascular displacement.

Main Methods:

• Retrospective analysis of OCTA scans from 18 iAMD patients with 6-month follow-up.
• Application of the Farneback motion tracking algorithm to assess en-face vascular displacement.
• Quantification of displacement in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC).

Main Results:

• Significant average coronal vascular displacement observed across all evaluated plexuses (SCP: 13.7 µm, DCP: 15.11 µm, CC: 19.02 µm).
• Reticular pseudodrusen (RPD) correlated with greater displacement in the DCP (p=0.047).
• RPD eyes showed highest DCP displacement (66.7%), while drusenoid PED showed greatest CC reorganization (100%).

Conclusions:

• Vectorial image analysis is a feasible method for quantifying microvascular displacement in iAMD.
• Retinal microvasculature undergoes significant tangential displacement and reorganization in iAMD.
• These microvascular changes may represent a compensatory response to ischemia in iAMD.