Laser Doppler Perfusion Imaging Is Useful in the Study of Raynaud’s Phenomenon and Improves the Capillaroscopic Diagnosis

Abstract

To investigate capillary morphology and skin blood flow of dorsal hands by nailfold videocapillaroscopy (NVC) and laser Doppler perfusion imaging (LDPI), respectively, in patients with primary Raynaud's phenomenon (PRP) and systemic sclerosis (SSc) and to compare the results with those obtained in healthy controls. The study group consisted of 142 patients with SSc, 88 patients with PRP, and 147 healthy controls. NVC was performed in all the groups examined. In patients with SSc the capillaroscopic pattern was classified as early, active, or late group pattern. A baseline skin blood flow determination of the dorsum of the subject's hands was acquired through a low-energy 670 nm Lisca Laser Doppler Perfusion Imager. In the healthy controls the perfusion distribution pattern was homogeneous, with a proximal-distal perfusion gradient. In patients with PRP, the perfusion distribution pattern was homogeneous, but the proximal-distal perfusion gradient was absent. Finally, in patients with SSc the perfusion distribution pattern was dyshomogeneous and a proximal-distal gradient was absent. The minimum perfusion, mean perfusion, maximum perfusion, and standard deviation, calculated as variation by means of each measurement site, were significantly different in all the groups examinated. NVC represents the best method to analyze microvascular damage in rheumatic diseases. LDPI improves the evaluation of vascular damage in patients with SSc. The LDPI and the capillaroscopic images fully matched the definition of the various stages of vascular digital damage in SSc.