Our results indicate that, in small resistance arteries of patients with primary aldosteronism, a pronounced fibrosis may be detected, even more evident than in blood-pressure-matched patients with essential hypertension.

A noninvasive and easily repeatable procedure (intraobserver and interobserver variation coefficient <13%) such as an evaluation of the arterioles in the fundus oculi by SLDF may provide similar information regarding microvascular morphology compared with an invasive, accurate and prognostically relevant micromyographic measurement of media-to-lumen ratio of subcutaneous small arteries.