Figure 2.

Contour plots describing the average distribution of the AF obtained from the 97 subjects with data for both eyes. The data is presented as a left eye. The axes indicate the retinal eccentricity in degrees relative to the center of the fovea. The numbers for each contour are relative qAF (qAF_i/qAF₈) where qAF₈ is the mean of the eight segments of the middle ring delineated by the two concentric interrupted black lines. The sampling areas were the 24 segments (+ sign; areas: 6600–12,400 pixels²) and additional locations (X sign; areas: 2000–10,000 pixels²) near the center and at the edges and corners of the image. Single dots are locations where linear or quadratic interpolations were used. The coefficients of variation for these relative data were 4% to 6% for the middle ring, 4% to 9% for the inner and outer rings (except near the optic disc: 9%–14%), and 15% to 25% inside the inner ring reflecting the variability in amount and extent of RPE melanin and of macular pigment. The gray rectangle marks the position of the internal fluorescent reference.