In the present study, the authors investigate the measure of peripheral blood flow as a surrogate marker of systemic vascular involvement in patients with exfoliation glaucoma (XFG), high-tension glaucoma (HTG), and normal-tension glaucoma (NTG) compared to controls. More studies have previously related systemic vascular dysfunction to glaucoma. In particular, decreased peripheral capillary blood flow at the nailfold has been found in patients with NTG, whereas it has previously been reported that patients with XFG have high degree of nailfold microvascular tortuosity. Here, the authors report a decreased resting peripheral capillary blood flow in patients with XFG and NTG compared to controls by means of a nailfold capillaroscopy (NFC.) A similar, but not significant tendency is found in HTG patients. Findings concerning XFG are highlighted and it is discussed that exfoliation material may lead to alterations in elastosis, levels of oxidative stress, and endothelial function, followed by vascular stiffness. Thus, the peripheral capillary blood flow in XFG may be particularly decreased related to the systemic nature of exfoliation material. While the results are interesting and supporting a systemic nature of XFG and NTG, the relatively large age difference among individuals in the glaucoma subgroups and controls as well as the lack of temperature control during NFC measurements should be considered. Moreover, significant inter-individual variations within all groups exists and future studies are needed to confirm the significance of the present study. In summary, the study is, however, well performed and the authors are highlighting the limitations of the study and adjusting for multiple co-variables. In conclusion, the findings provide supportive evidence of decreased peripheral capillary blood flow as a part of the XFG and NTG phenotypes and contribute to increasing evidence of a systemic nature of glaucoma.