Quantitative Evaluation of Geographic Atrophy Progression Using Geographic Atrophy Lesion Front Displacement

Area of Science:

• Ophthalmology
• Medical Imaging
• Biostatistics

Background:

• Geographic atrophy (GA) is a leading cause of vision loss in age-related macular degeneration (AMD).
• Accurate quantification of GA progression is crucial for clinical trials and patient management.
• Current metrics for GA progression may have limitations in temporal behavior and variability.

Purpose of the Study:

• To evaluate the temporal behavior and relative variability of lesion front displacement for quantifying GA progression.
• To compare the performance of lesion front displacement with conventional GA progression metrics.

Main Methods:

• Retrospective analysis of 103 untreated eyes with GA from the MAHALO clinical trial.
• Fundus autofluorescence images analyzed at baseline and 6, 12, and 18 months.
• Calculated five progression metrics: area change, square root area change, perimeter change, perimeter-adjusted growth rate (λ'PA), and lesion front displacement.

Main Results:

• Lesion front displacement showed better linearity (R2 = 0.504) compared to area and square root area metrics.
• Area, square root area, perimeter, and λ'PA exhibited lower goodness of fit to a linear model.
• Lesion front displacement demonstrated significantly lower dispersion and variability across follow-up intervals compared to perimeter change and λ'PA.

Conclusions:

• Lesion front displacement provides a more consistent linear approximation and lower variability for GA progression assessment.
• This margin-based metric may serve as a valuable complementary tool for longitudinal GA assessment in AMD.