AS-OCT Considered Comparable to Gonioscopy for Triage Purposes

For virtual glaucoma care, this imaging modality can save time and increase efficiency—but direct examination remains the gold standard. Photo: Sharon Keh, OD. Click image to enlarge. The use of remote, asynchronous glaucoma clinics is growing as a means of meeting the care needs of a rapidly growing aging population. Gonioscopy is the current standard of care for assessing whether the angle is closed or open but requires a trained technician or a specialist to perform it. On the other hand, anterior segment OCT (AS-OCT) has shown comparable diagnostic accuracy to gonioscopy, and images can be graded asynchronously and remotely. To determine whether AS-OCT could replace gonioscopy as a triage tool for angle assessments in glaucoma clinics, researchers screened new referrals at a single center using both methods. Their findings, published recently in Eye, showed that AS-OCT is a safe and effective triage tool.In the study, all new referrals at a single center in a five-month period (n=384 eyes) underwent gonioscopy performed by trained technicians (ophthalmic science practitioners) and AS-OCT assessment of the angle. The technicians labeled angles as open or closed, and two glaucoma subspecialists graded the AS-OCT images as open or closed.A total of 358 eyes were included in the analysis, since 26 eyes were unable to undergo gonioscopy. The researchers found that AS-OCT had a 97% sensitivity and 36% specificity for identifying an open angle. The test’s positive predictive value was 95.7% and the negative predictive value was 46%.“Ultimately, we propose that AS-OCT is safe to use as a triage tool in virtual assessments of patients referred into a glaucoma service,” the researchers concluded in the Eye paper. “Assessments are well tolerated and can also obtain pachymetry readings. Use of AS-OCT will save time compared to the traditional processes of separate corneal pachymetry measurements and gonioscopic angle grading. It can allow us to be as efficient as possible in our work, while maintaining high standards of care.”Click here for the journal source. Dhalla A, Evans T, Pilling J, Auger G. Comparison of anterior segment optical coherence tomography versus technician led gonioscopy as a triage tool for anterior chamber angle status. Eye (Lond). July 7, 2025. [Epub ahead of print].