APOE and retinal disorder: Several exclusion criteria were applied: lack of CSF AD core biomarkers data within 12 months of the OCT-A scan (n = 1363), not fulfilling the diagnostic criteria for MCI (n = 115), ophthalmological conditions that could interfere with OCT-A measurements (n = 23; n = 8 due to retinal surgery, n = 6 due to retinopathy, n = 5 due to open angle glaucoma, n = 3 due to IOP > 24 mmHg, n = 1 due to other reasons) and finally, lack of information on APOE ε4 status (n = 3).