Fig. 4. Anterior chamber angle width. The angle has closed and the iris now lies against the trabecular meshwork, obstructing outflow. If closure has occurred around a significant portion of the circumference of the angle, intraocular pressure will rise. (Kolker AE, Hetherington J Jr: Becker and Shaffer's Diagnosis and Therapy of the Glaucomas, p 43. St. Louis, CV Mosby, 1970)