Figure 3: Two examples of how interpolation between B-scans results in inaccurate macular thickness maps. (a) Undersampled thickness maps from a single normal subject and one with dominant drusen retain relatively similar qualitative appearance to that of their respective 128 B-scan maps. (b) The thickness differences between the standard of 128 scans and each sequential level of B-scan density show the areas of the macula most effected by undersampling in a normal subject and a subject with dominant drusen. Even with 32 B-scans significant error is generated through the central fovea (where the contour is changing most rapidly) in a normal subject. This effect is greatly enhanced in the subject with drusen wherein error is generated not only in the central fovea but also broadly across the entire scanning area.