Figure 1.

Illustration of the anterior laminar cribrosa surface depth (ALCSD) computation approach. From the circle scan of each eye (upper B-scan image) the internal limiting membrane (ILM), retinal nerve fiber layer (RNFL), Bruch's membrane (BM), and anterior scleral surface are computed by SALSA autosegmentation. Choroidal thickness was computed from the circle scan as the average distance between the BM and the anterior scleral surface. The sclera reference was computed as a plane parallel to the BM reference plane and distant in magnitude equal to the average choroidal thickness (computed from the circle scan). ALCSD was then defined as the average vertical distance between the sclera reference plane and points all the lamina falling within a 3 pixel-radius from the BMO centroid projection on the anterior lamina surface.