Fig. 13c Continued. H. View of same angle through a Zeiss lens. The angle recess is still hidden from view by the iris. I. View of same angle with indentation gonioscopy. There is a dramatic deepening of the chamber angle by a temporary posterior displacement of aqueous. The iris moves posteriorly opening the angle. In this case, the scleral spur is seen, green arrow. This angle is optically closed in this region. The knowledge the angle is optically closed instead of covered by PAS is important in predicting the outcome of laser iridotomy. The Spaeth grading of this angle is (A)C20b3+. A review of the Spaeth system implies the actual insertion of the iris is just below the scleral spur, the apparent insertion is Schwalbe's line, and the iris bows significantly. J. Appearance of angle post laser iridotomy. Pigment is dispersed postiridotomy and seen covering part of the inferior angle. The grading of this angle is now a C40f1+ptm. Thus the angle changes from a (A)C20b3+ to a C40f. This type of chart documentation reveals a great deal about the change in angle anatomy post iridotomy.