The AUC of NCAM/ABCA1 dual-labeled exosomal Aβ42/40 for diagnosis of SCD was higher than that of Aβ42, T-tau, and P-T181-tau; the AUC of NCAM/ABCA1 dual-labeled exosomal miR-384 for diagnosis of SCD was higher than that of Aβ42, Aβ42/40, T-tau, P-T181-tau, and NfL.miR-384 can downregulate the expression and activity of BACE. Here, ABCA1 is linked to Schnyder corneal dystrophy.