Table 1 Inclusion criteria for all participants

Inclusion criteria for all participants

Available CSF, PET, CT or MRI data to evaluate the presence/absence of neurodegeneration (preferably within 1 year of inclusion in this study)

Absence of ocular conditions that could influence tear biochemical parameters (including eye infection, eye inflammation, eye surgery within the last 28 days or other acute eye conditions)

Absence of neurological or systemic chronic conditions known to interfere with retinal thickness (e.g. glaucoma, diabetes mellitus)

Absence of ocular conditions interfering with OCT quality/retinal thickness: e.g. severe cataract, age-related macular degeneration, and glaucoma

Written informed consent obtained and documented

Age > 50 years

No indications that follow-up (up to 24 months) is not possible