Using anterior segment OCT to risk-stratify primary angle closure suspects

Gonioscopy is the clinical standard for detecting patients at risk for primary angle closure glaucoma (PACG). However, anterior chamber angle imaging can be useful to identify iris configuration and narrow angle.1 The landmark Zhongshan Angle-Closure Progression (ZAP) Trial showed that narrower angle width measured by anterior segment OCT (AS-OCT) was predictive of angle closure progression in both untreated and laser-treated eyes.2,3 A separate cross-sectional study found that iridotrabecular contact (ITC) on AS-OCT was associated with greater severity of angle closure disease.4 Therefore, presence of narrow angles or ITC on AS-OCT may indicate high-risk PACS that warrants closer monitoring or earlier treatment.

References

1. European Glaucoma Society Terminology and Guidelines for Glaucoma, 5th Edition. Br J Ophthalmol 2021 Jun;105(Suppl 1):1-169. doi: 10.1136/bjophthalmol-2021-egsguidelines.
2. Xu BY, Friedman DS, Foster PJ, et al. Ocular Biometric Risk Factors for Progression of Primary Angle Closure Disease: The Zhongshan Angle Closure Prevention Trial. Ophthalmology. 2021;0(0). doi:10.1016/J.OPHTHA.2021.10.003
3. Bao YK, Xu BY, Friedman DS, et al. Biometric Risk Factors for Angle Closure Progression After Laser Peripheral Iridotomy. JAMA Ophthalmol. Published online April 27, 2023:e230937. doi:10.1001/jamaophthalmol.2023.0937
4. Zhang X, Guo PY, Lin C, et al. Assessment of Iris Trabecular Contact in Eyes with Gonioscopic Angle-Closure. Ophthalmology. 2023;130(1):111-119. doi:10.1016/j.ophtha.2022.08.017

Contributor: Benjamin Xu, MD, PhD, Los Angeles, California, United States

Tip of the Month Manager: Karin Öyo-Szerenyi
Tip of the Month Editors in Chief: Manuele Michelessi, Francesco Oddone