Spaeth Grading System

1.   Iris Insertion:

A = Anterior to Schwalbe's line (SL)

B = Between SL and scleral spur

C = Scleral spur visible (common in blacks and Asians)

D = Deep: ciliary body visible (common in whites)

E = Extremely deep: greater than 1 mm of ciliary body is visible

2.   Angle of Anterior Chamber

The angular width that is measured as the angle between a line parallel to the corneal endothelium at Schwalbe's line and a line parallel to the anterior surface of the iris.

3.   Curvature of Iris

b = bowing anteriorly

p = plateau configuration

f = flat

c = concave posterior bowing

4.   Pigmentation of Posterior Trabecular Meshwork (PTM)

Viewing at 12 o'clock in the angle with mirror at 6 o'clock position, pigmentation graded on a scale of 0 (no PTM pigment seen) to 4+ (intense PTM pigment).