I. Analysis of the structure-function relationship in the linear scale with the broken-stick model We also applied the broken-stick model to the VF data and the MDB structural parameters both in the linear scale. When the VF TD data was transformed to the linear scale, the observation that "the structurefunction relationship displayed a plateau, with neuroretinal rim thickness values being unrelated to VF values" was not readily visualized in some of quadrants/ sectors (Figure S1). Further statistical evaluation shows that the slopes above the tipping point are not significantly different from 0, as shown in Table S1. We added in a model-agnostic lowess smoothing curve to compare with the fitted broken-stick model on the data of unlogged VF TD against the MDB. The broken stick model fit didn't match with the lowess fit for the Temporal-Inferior region and the Inferior quadrant. Furthermore, the breakpoint didn't exist for the nasal and temporal quadrants and the TS and NI octants, as shown in the table below where the pvalues are greater than 0.05 (Table S1). For the breakpoints which did exist (i.e. the global value, superior and inferior quadrants, TI and NS sectors), the fitted breakpoints in the linear scale were different for the breakpoints obtained in the logarithmic fits and not encompassed by their respective confidence intervals from the logarithmic scale. As a final remark, indeed the question of whether the structure-function relationship between the VF data and the neuroretinal rim data should be established as a logarithmic-linear scale or as a linear-linear scale has been actively studied in the past two decades. 1-4 A variety of models have been employed to describe the structure-function relationship in both the linear and curvilinear regimes. With this rich history of research on this topic behind us, we primarily presented the data by looking at the VF in the logarithmic scale (or in its native "untransformed" form) since it is more clinically utilized. Also, the logarithmic scale helps to distinguish among the moderate and severe glaucomatous patients.