Two new parameters to assess anterior chamber angle for SS-OCT images

Abstract

In this paper, we propose an automatic quantitative assessment method of the anterior chamber angle of the eye using swept source optical coherence tomography (SS-OCT) images. The angle structure was assessed by two new parameters: 1) mean of continuous measurement of angle opening distance (mAOD) centered on Schwalbe's line; and 2) area of the anterior chamber (AAC). In this research, two hundred and fifty-two SS-OCT images were analyzed. The measurements of open and closed angle in SS-OCT images were compared with that of Schwalbe's line based single angle assessment (AOD_sl, ARA_sl). Our continuous based AOD measurement shows over 93% correlation with the single based AOD angle assessment but provides a more reliable and accurate measurement for open and closed angle SS-OCT images. These newly proposed parameters give a better representation of the angle width for capturing the nature of the angle dynamics involved in different forms of angle closure or open angle glaucoma.