Figure 3.

(A) NMF spectral output (36-year-old male, near-periphery). S0 is the usual BrM spectrum; SX is a second BrM spectrum. S1, S2, and S3 are the basic LF/ML spectra. (B) Abundance images for spectra recovered from tissue in (A); localization of S3 to ML; dual BrM spectra. BrM is exposed where a flap (black arrows) was everted in the RPE monolayer. S0 localizes to BrM, with variegation corresponding to the intercapillary pillars and with no “nuclear shine-through” as commonly seen in other BrM signals. However, the abundance of the longer wavelength SX also localizes to BrM, but in a completely homogeneous distribution, and displays prominent nuclear shine-through. Indeed, for the BrM signals, there is a slight decorrelation (Pearson correlation coefficient, r = −0.11). The underside of the flap is brighter than the rest of the RPE because most melanin is apical, increasing absorption of the AF signal. The abundances of LF/ML spectra S1 and S2 are quite similar (r = +0.76; S1 not shown). Note the differences between the S2 and S3 abundances, as demonstrated in the overlay panel and insert: S2 is abundant in areas corresponding with LF granules, while S3 localizes to areas rich in ML granules. Compare overlay inset with inset in RGB panel. S2 and S3 are actually uncorrelated (r = −0.19). The correlation of S1 and S3 is small (r = +0.04). As would be expected, the correlations of the BrM spectra with the LF/ML spectra range from uncorrelated (S3 and SX, r = +0.01) to anticorrelated (S1 and SX, r = −0.55).