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Sakata et al. (135) compare the ability of conventional automated perimetry using the SITA Standard 24-2 test procedure and Humphrey Matrix frequency doubling technology (FDT) perimetry using the 24-2 test pattern to distinguish between patients with glaucomatous-appearing optic discs (GAOD) and normal control subjects. The overall findings suggest that both perimetric techniques were able to provide similar information in a reasonably comparable amount of time. In general, this study was performed in a careful, concise manner and serves as a good example of performing a cross-sectional clinical comparison. I would like to briefly comment on several key aspects of this study. Firstly, inclusion and exclusion criteria can have an important impact on a clinical study, and in this case whether one uses optic disc criteria, visual field criteria or both can dramatically influence the population being testing. In this instance, optic disc criteria were only considered for inclusion in the study, and the two perimetric tests were compared for the same participants. Secondly, readers should be aware that the majority of participants had early visual field loss, which might help to account for only moderate agreement between the two perimetric tests and the small percentage of abnormal results (early glaucomatous damage can vary from one test time to another and may not be manifest on all initial visual fields). Finally, the authors recommend using a combination of SITA and Matrix tests to improve detection of early glaucomatous loss. However, it should be kept in mind that this will significantly lengthen the clinic visit and may be cumbersome in some clinical settings. The authors of this paper should be commended for doing excellent job of evaluating these two test procedures.