Figure 2:

Measuring changes in the region of progression (ROP): (A and B) The derived circular b-scans for two visits (left) and the enface image with the location of the derived circle scans (right panels of A and B). (C) A plot of the cRNFL thickness in the study region for the first (solid black curve) and Nth visit (dashed blue curve). The difference between them is shown as the light blue line at the bottom of the plot. (D) Enlarged image of study region in panel C. Red arrow indicates the location and amount of loss at the point of maximal loss. Starting from this point and moving along the difference curve to the left (blue dashed arrow) and to the right (orange dashed arrow), the leading (close to fixation, blue arrow) and trailing edges (orange arrow) were determined as the first location on the difference curve which fell below −5 μm. The ROP width was taken as the distance (in degrees) between the leading and trailing edges. Hatched region indicates the area of total loss in the ROP (μm²). The eye shown corresponds to eye 11 in Fig. 3.