Towards 'automated gonioscopy': a deep learning algorithm for 360° angle assessment by swept-source optical coherence tomography. Issue 10 (12th April 2021)

• Record Type: Journal Article
• Authors: Porporato, Natalia; Tun, Tin A; Baskaran, Mani; Wong, Damon W K; Husain, Rahat; Fu, Huazhu; Sultana, Rehena; Perera, Shamira; Schmetterer, Leopold; Aung, Tin
• Is Part Of: British journal of ophthalmology. Volume 106:Issue 10(2022)
• Page Start: 1387
• Page End: 1392
• Publication Date: 2021-04-12
• Subjects: angle -- glaucoma -- imaging; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjophthalmol-2020-318275
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Aims: To validate a deep learning (DL) algorithm (DLA) for 360° angle assessment on swept-source optical coherence tomography (SS-OCT) (CASIA SS-1000, Tomey Corporation, Nagoya, Japan). Methods: This was a reliability analysis from a cross-sectional study. An independent test set of 39 936 SS-OCT scans from 312 phakic subjects (128 SS-OCT meridional scans per eye) was analysed. Participants above 50 years with no previous history of intraocular surgery were consecutively recruited from glaucoma clinics. Indentation gonioscopy and dark room SS-OCT were performed. Gonioscopic angle closure was defined as non-visibility of the posterior trabecular meshwork in ≥180° of the angle. For each subject, all images were analysed by a DL-based network based on the VGG-16 architecture, for gonioscopic angle-closure detection. Area under receiver operating characteristic curves (AUCs) and other diagnostic performance indicators were calculated for the DLA (index test) against gonioscopy (reference standard). Results: Approximately 80% of the participants were Chinese, and more than half were women (57.4%). The prevalence of gonioscopic angle closure in this hospital-based sample was 20.2%. After analysing a total of 39 936 SS-OCT scans, the AUC of the DLA was 0.85 (95% CI:0.80 to 0.90, with sensitivity of 83% and a specificity of 87%) to classify gonioscopic angle closure with the optimal cut-off value of >35% of circumferential angle closure. Conclusions: The DLA exhibited good diagnostic performance for detection of gonioscopic angle closure on 360° SS-OCT scans in a glaucoma clinic setting. Such an algorithm, independent of the identification of the scleral spur, may be the foundation for a non-contact, fast and reproducible 'automated gonioscopy' in future.