Cumulative retardance (A), DOPU (B), and thresholded DOPU at 0.5, projected on top of the log intensity image (C). The threshold marks red DOPU values equal or lower than 0.5. B-scan is from Subject 12, one of the older subjects with low retardance below the RPEBM complex. Retardance is similar, yet elevated, to the low-retardance observed in young Subject 10. Consistent with this slight increase in retardance, the subject has several localized areas in or near the RPE with low-DOPU (<0.5)