Figure 1: A custom MatLab program was designed to generate ETDRS thickness plots from the raw thickness data exported using the Cirrus Research Browser. (a) Central subfield thickness values taken directly from the Cirrus correlate highly with those obtained from our Matlab-based algorithm. (b) Bland-Altman plot further reveals excellent agreement between the two measurements. Gray line represents the mean difference between the measurements (0.42 μm), and the dashed lines represent 95% confidence limits (1.09 μm and −0.25 μm). These data indicate virtually no loss in accuracy when using the MatLab derived thickness maps for subsequent analysis. Open circles: normals; crosses: pathology subjects; CSF = central subfield.