Related Experiment Video
Updated: Nov 2, 2025
04:25
Author Spotlight: Bridging Gaps in Anatomy and Establishing a Foundation for Algorithmic Studies
Published on: December 15, 2023
3.2K
Validating Ellipsoid Zone Area Measurement With Multimodal Imaging in Choroideremia
Yi Zhai1, Sarah Oke1, Ian M MacDonald1
1Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada.
Translational Vision Science & Technology
|June 10, 2021
Summary
En face ellipsoid zone (EZ) mapping reliably quantifies retinal structure in choroideremia patients. Measuring EZ band length offers a faster alternative for clinical trials assessing photoreceptor integrity.
Area of Science:
- Ophthalmology
- Medical Imaging
- Genetics
Background:
- Choroideremia is a genetic disorder causing progressive vision loss.
- Accurate outcome measures are needed for clinical trials in choroideremia.
Purpose of the Study:
- To evaluate en face ellipsoid zone (EZ) maps as outcome measures for choroideremia research.
- To assess the reliability and correlation of EZ measurements.
Main Methods:
- Retrospective analysis of spectral domain-optical coherence tomography scans from 12 choroideremia patients.
- Manual segmentation of EZ slabs to create en face EZ maps.
- Intergrader reliability assessment and correlation analysis between EZ area and length.
Main Results:
- EZ area measurements demonstrated excellent intergrader agreement (ICC=0.992).
- Average EZ band length in meridians strongly correlated with EZ area (r=0.929).
- Fundus autofluorescence area was larger than EZ area, suggesting early photoreceptor inner segment loss.
Conclusions:
- En face EZ mapping is a reliable tool for quantifying photoreceptor structure in choroideremia.
- Average EZ band length provides a time-efficient alternative for EZ area estimation.
- Photoreceptor inner segment loss may precede retinal pigment epithelium loss in choroideremia.
