Increased choroidal thickness in adults with Down syndrome.

Introduction: People with Down syndrome (DS) are particularly susceptible to Alzheimer's disease (AD) due to the triplication of the amyloid precursor protein () gene. In this cross-sectional study, we hypothesized that choroidal thinning reported in sporadic AD (sAD) is mirrored in adults with DS.

Methods: The posterior pole of the eye for 24 adults with DS and 16 age-matched controls (Ctrl) were imaged with optical coherence tomography. Choroidal thickness (ChT) was measured and analyzed in relation to cognitive status and cerebral amyloid beta (Aβ) load.

Results: ChT was increased in people with DS (pwDS) compared to Ctrl. This increase was associated with gender differences and positively correlated with cerebral Aβ load in a small subset. There was no significant correlation detected between ChT and age or cognitive status.

Discussion: In contrast to sAD this study found a significantly thicker choroid in pwDS. Whether these changes are related to Aβ pathology in DS needs further investigation.