The graph represents a pair of HR2 and LRI values for each of 36 normal subjects and 31 glaucoma subjects. HR2 pixels (or dots) show a high positive correlation with the RNFL thickness. The low correlation between LRI dots and the RNFL thickness likely denotes the lack of relatioriship between those components (i.e. glial tissue, blood vessels, etc) and the glaucomatous degeneration of the ganglion cells.