A post hoc analysis of the Phase 3 GATHER1 and GATHER2 clinical trials has revealed that baseline ellipsoid zone (EZ) integrity features, assessed using spectral-domain optical coherence tomography (SD-OCT), may help predict the rate of geographic atrophy (GA) progression in patients with dry AMD.

The analysis, presented at the 2024 ASRS Annual Meeting in Stockholm, Sweden, included 332 patients from the pooled sham groups of both trials. GA growth rates over the first 12 months were categorized into quartiles: very slow, slow, moderate, and fast. SD-OCT scans were segmented using a machine-learning–enhanced platform to extract measures of EZ integrity, including total and partial EZ attenuation and partial EZ-GA gap.

Results showed that eyes with faster GA growth rates had significantly greater baseline total and partial EZ attenuation. Mean total EZ attenuation ranged from 22.7% in the very slow group to 38.6% in the fast group, while mean partial EZ attenuation ranged from 36.0% to 60.1%. Additionally, eyes with faster GA growth had larger baseline partial EZ-GA gaps, ranging from 22.0% in the very slow group to 36.9% in the fast group.

As GA growth rates can vary considerably among patients with dry AMD, identifying baseline predictors of progression is essential for optimizing treatment strategies and clinical trial design. The association between EZ integrity and GA growth rate highlights the potential role of advanced imaging techniques in personalizing the management of this condition.