OCT Angiography to Predict Geographic Atrophy Progression using Choriocapillaris Flow Void as a Biomarker

Area of Science:

• Ophthalmology
• Retinal Imaging
• Age-Related Macular Degeneration Research

Background:

• Geographic atrophy (GA) is a leading cause of vision loss in nonexudative age-related macular degeneration (AMD).
• Predicting the rate and location of GA expansion is crucial for managing patients with advanced AMD.

Purpose of the Study:

• To investigate the relationship between choriocapillaris (CC) flow void (FV) percentage and the growth rate of geographic atrophy (GA).
• To determine if CC FV variations surrounding GA predict regional GA growth.

Main Methods:

• A prospective, longitudinal study involving subjects with GA secondary to nonexudative AMD.
• Optical coherence tomography angiography was used to image the CC, and FV percentage was quantified.
• GA growth rate was calculated based on changes in GA area over time.

Main Results:

• GA expansion rate positively correlated with increased CC FV percentage within the macular region (r=0.69, P=0.038) and a 2° margin around GA (r=0.76, P=0.013).
• Regions with baseline CC FV within 480 µm of the GA margin had a 33% higher likelihood of becoming atrophic compared to regions without CC FV.

Conclusions:

• GA expansion rate is significantly correlated with CC FV density in the macula and around the GA margin.
• The extent of FV surrounding GA is associated with disease progression into those areas.
• CC FV analysis shows potential for predicting GA growth in advanced nonneovascular AMD.