Salt intake determines retinal arteriolar structure in treatment resistant hypertension independent of blood pressure

► We performed in vivo measurements of retinal arteriolars with scanning laser doppler flowmetry in patients with treatment resistant hypertension. ► Wall to lumen ratio, wall thickness and wall cross section area were strongly associated with urinary sodium excretion but not with 24 h blood pressure. ► Urinary sodium excretion emerged as the only independent determinant of wall thickness and wall cross section area of retinal arteriolars. ► Salt intake influences the structure of retinal arterioles independent of blood pressure in treatment resistant hypertension.