Fig. 1

Classification of the anterior chamber angles with a preset 12-degree angle. With the apex being located in the iris recess, one arm of the angle was adjusted to pass through a point on the trabecular meshwork 750 μm from the scleral spur. The angle was classified into: open (A), narrow (B) and closed (C) according to the location of the other arm of the preset angle. Four quadrants in the same eye were assessed. Eyes with narrow and/or closed angle in three quadrants and above were defined as at high-risk of angle closure (HRAC)