Association of Ellipsoid Zone Integrity Features with Visual Acuity in Dry Age-Related Macular Degeneration.

Abstract

Purpose : Ellipsoid zone (EZ) integrity has been associated with visual function in multiple retinal conditions. This study aims to evaluate the association between EZ integrity features as measured on SD-OCT with visual acuity (VA) in dry age-related macular degeneration (AMD).

Methods : This IRB-approved retrospective image analysis study evaluated eyes with dry AMD to provide quantitative assessment of EZ integrity features and VA analysis. SD-OCT was performed (Spectralis, Heideiberg; or Cirrus, Zeiss) and exported for analysis. For EZ integrity assessment, a machine learning (ML)-enhanced segmentation platform was utilized to provide panmacular segmentation of the EZ and retinal pigment epithelium (RPE) bands. Following initial automated segmentation, a certified reader reviewed every B-scan for segmentation accuracy and corrected any segmentation errors. Measures of EZ integrity included partial and total EZ attenuation burden, indicated by the percentage of the macular cube with EZ-RPE thickness ≤ 20 μm and EZ-RPE= 0 μm, respectively, and EZ-RPE central subfield thickness (CST), i.e. central 1 mm. These measurements were compared in eyes with excellent VA (≥ 20/25 Snellen) and eyes with limited VA (≤20/40 Snellen). In addition, an analysis was performed based on evaluating the mean VA in eyes with total loss of EZ in the CST (i.e, =0 μm), partial loss (i.e., >0 and ≤20 μm) and EZ preservation (i.e,>20 μm).

Results : This analysis included 395 eyes of 395 patients. In the first assessment, subjects with excellent VA showed lower baseline partial and total EZ attenuation (n= 368, mean= 4.51% and 1.37%, respectively) than subjects that had limited VA (n=635, mean= 28.26% and 17.98%, respectively). In addition, baseline EZ-RPE CST was greater in eyes that had excellent VA (mean= 32.1µm) than eyes that had limited VA (mean= 12.0µm). When evaluated based on EZ parameters, the mean VA with total EZ loss in the CST was 20/200, with partial EZ attenuation in the CST was 20/70, and with EZ preserivation of the CST the mean VA was 20/30. The results in both assessments were highly statistically significant (All p-values<10^-60).

Conclusions : This report reinforces the critical link between EZ integrity and VA in dry AMD, reflecting its functional role in dry AMD patients and supporting the use of EZ integrity as a key endpoint for therapeutic development.

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