Evaluating the Impact of Ellipsoid Zone Integrity on Future Vision Loss in Dry Age-Related Macular Degeneration

Abstract

Purpose : Predicting risk of vision loss in dry age-related macular degeneration (AMD) is an important factor in identifying eyes that could benefit from therapeutic intervention. Ellipsoid zone (EZ) integrity has been demonstrated to be a key marker of disease burden and functional loss in retinal diseases, including dry AMD. The purpose of this analysis was to characterize baseline EZ integrity features in eyes with dry AMD and evaluate any association with two-year future vision loss.

Methods : This was an IRB-approved longitudinal retrospective image analysis study that evaluated the eyes with dry AMD with 2-years of longitudinal follow-up. Baseline SD-OCT macular cubes were exported and a machine learning (ML)-enabled feature extraction tool was used to derive EZ integrity parameters based EZ and retinal pigment epithelium (RPE) segmentation. Certified readers reviewed each B-scan of every macular cube and any segmentation errors were corrected, as needed. EZ integrity parameters analyzed include partial and total EZ attenuation (%), determined by the percentage of macular cube with EZ-RPE thickness ≤ 20 μm and EZ-RPE= 0 μm, respectively, and EZ-RPE thickness in the central subfield (1-mm). Comparative assessment of baseline EZ integrity metrics was conducted between subjects that had significant visual acuity (VA) loss (defined as 2 lines or more) and subjects that had stable VA (defined as less than 2-line VA loss) over a 2-year follow-up period.

Results : The study analyzed 285 eyes of 285 subjects with dry AMD. Eyes that developed significant VA loss demonstrated nearly double the baseline partial and total EZ attenuation (mean= 23.37% and 12.83%, respectively) compared to subjects with stable VA (mean= 12.47% and 6.92%, respectively). In addition, baseline EZ-RPE central subfield mean thickness was significantly higher in eyes that had stable VA (mean= 24.8 µm) compared to those eyes with significant VA loss (mean= 15.3 µm). All associations were statistically significant (p <0.000001).

Conclusions : Increased baseline EZ integrity disruption is associated with future VA loss in patients with dry AMD, which may be useful for predicting future functional outcomes and utilizing these metrics for clinical trial targeted enrollment strategies and potential therapeutic interventions.

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