Syed ZA, et al. - The connection between the peripheral endothelial cell count (ECC) and known clinical markers of Fuchs endothelial corneal dystrophy (FECD) in advanced cases are ascertained in this study. In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and central corneal thickness (CCT). The peripheral ECC ought to be added to the clinical parameters used to assess FECD severity.