MAPT and frontotemporal dementia: Reduced RNFL and GC-IPL thickness has been reported in 17 FTD eyes [26], but no significant difference was shown in larger studies that utilized CSF total tau: β-amyloid biomarker to exclude AD and categorize FTD patients into subgroups based on molecular pathology (tauopathy, TDP-43, unknown) [27, 28].