Quantitative Contrast Sensitivity Longitudinal Changes Correlate Better than Visual Acuity with Geographic Atrophy Size Progression in Advanced Dry AMD: a New Clinical Endpoint

Abstract

Purpose : VA is not well-correlated with geographic atrophy (GA) size and progression. More sensitive functional endpoints that would better show the benefit of new treatments in GA trials are needed. Here, we explore quantitative contrast sensitivity (qCSF) as a functional endpoint for GA. We explored the correlation between GA size and qCSF both cross-sectionally and longitudinally.

Methods : Same-day qCSF contrast sensitivity (CS), optical coherence tomography (OCT), and fundus autofluorescence (FAF) were performed. Regression models were used for associations between semiautomatic Heidelberg Region Finder-measured total GA size on FAF, qCSF metrics, and Snellen visual acuity (VA).

Results : 83 foveal-involving GA eyes (defined as cRORA on OCT), 30 with more than one visit. Average follow up was 17.2 months (4-37). Cross-sectionally (n = 83), total GA was associated with area under the logCSF curve (AULCSF), contrast acuity (CA) and CS thresholds at 1, 1.5, 3, 6 (β = -0.01 to -0.02 all p<0.05), but not with VA (β = 0.01, p = 0.47). Pearson correlations for GA size and qCSF outcomes (r = -0.31 to -0.35, all p<0.05) vs VA (r = 0.14, p = 0.23). Longitudinally (n = 30), the change in total GA size (ΔGA) size was associated with changes in AULCSF, CA and CS thresholds at 1, 1.5 and 3cpd (β=-0.04 to -0.06, all p<0.05,) but not with the change in VA. (β= -0.01, p= 0.88). Similarly, Pearson correlations revealed that longitudinal change in total GA size was correlated with longitudinal changes in CS (r= -0.42 to -0.64, all p<0.05) but not with longitudinal change in VA (r=0.03, p=0.88)

Conclusions : Total GA size and longitudinal change in total GA size are associated with qCSF CS and longitudinal changes in CS, but not with VA or longitudinal change VA. CS may be a better functional endpoint to measure treatment effect in clinical trials for geographic atrophy in AMD.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.