Is arterial stiffness in the carotid artery associated with choroidal thinning in patients with pseudoxanthoma elasticum or controls?

Purpose Patients with pseudoxanthoma elasticum (PXE) develop calcification of Bruch's membrane (BM) and choroidal thinning, as well as calcification of intracranial arteries, leading to arterial stiffness. We investigated whether arterial stiffness is associated with choroidal thinning in PXE patients, besides the presumed effect of BM calcification. Methods Cross‐sectional study with 75 PXE patients and 40 controls. Macular choroidal thickness was measured using optical coherence tomography scans. Functional magnetic resonance imaging was used to calculate the pulsatility index (PI) of the carotid siphon as a measure of arterial stiffness. Associations between PI and choroidal thickness were investigated using linear mixed effects models adjusted for age and ocular axial length. Furthermore, we investigated choroidal thickness in relation to the presence of retinal pigment epithelium (RPE) atrophy, its topographical distribution and age. Results Median age was 58 years (IQR 53–66) in PXE patients and 62 years (IQR 56–67) in controls (p = 0.08). Pseudoxanthoma elasticum (PXE) patients had a thinner choroid than controls (138 μm versus 248 μm, p