Repeatability and Reproducibility of Peripapillary Choroidal Thickness Using a Medical Image-Processing Software

Abstract Although choroid has been shown to have a vital role in the pathophysiology of many ocular diseases, its role in the pathogenesis of several other conditions remains uncertain. The authors propose a novel methodology to establish a more accurate Peripapillary Choroidal Thickness (PPCT), using an image-processing software. This study sought to evaluate the reproducibility and repeatability of PPCT evaluation with ImageJ software in healthy volunteers. Forty-eight eyes of ۲۴ volunteers were subjected to PPCT area determination, after imaging acquisition and recording with Spectral-domain Optical Coherence Tomography (SD-OCT) Heidelberg Spectralis®, during two different sessions, by two blinded assessors. The age of the subjects was ۲۹.۲ ± ۴.۵ years (mean ± SD). The Coefï cient of Repeatability (CR) average measurements of PPCT area was ۱۷.۰۶ mm۲ and ۹.۴۸ mm۲ correspondingly, for the ï rst and second examiners. Intra-class Correlation Coefï cient (ICC) was ۰.۹۹۴ (۹۵% CI ۰.۹۸۹ to ۰.۹۹۷) and ۰.۹۹۸ (۹۵% CI ۰.۹۹۷ to ۰.۹۹۹). Inter-observer Concordance Correlation Coefï cient (CCC) was ۰.۹۹۸ (۹۵% CI ۰.۹۹۶ to ۰.۹۹۹) for both examiners. Intra-observer CCC ranged from ۰.۹۹۷ (۹۵% CI ۰.۹۹۶ to ۰.۹۹۹) to ۰.۹۹۸ (۹۵% CI ۰.۹۹۷ to ۰.۹۹۹), correspondingly, for the first and second examiners. The PPCT quantification by means of the proposed methodology showed good inter- and intra-observer agreement for both operators, indicating feasibility and good reproducibility of the proposed methodology. This approach might be used in different clinical settings and potentially contributes to elucidation of the choroid role in ocular pathology.