In this presentation from AAO 2016, Clement C.Y. Tham, MD, discusses apositional angle closure with ocular hypertension, evidence from imaging for plateau iris syndrome, darkroom gonioscopy, and ultrasound biomicroscopy (UBM). He argues that the evidence from imaging for lens mechanism includes

• Slit-lamp biomicrosocpy examination
• Indentation gonioscopy: the Mount Fujiyama
• Quantitative AS anatomical parameters from UBM/AS-OCT, which includes

- The lens vault-anterior chamber depth, which is the most useful for lens being a mechanism for angle closure

- The anterior vault, which is associated with IOP reduction with lens extraction

- The relative lens vault,which is related to primary angle closure