APOE and Schnyder corneal dystrophy: The SCD-concentration group had a significantly higher frequency of CSF Aβ42/40-positive individuals (p = .002), had lower levels of CSF Aβ42/40 (p = .001), had higher MADRS-9 scores (p = .037), and showed a tendency to have a higher frequency of APOE-ε4 carriers (p = .056) than the control group (Table 1).