Background Utilising fluorescence optical imaging (FOI), the distribution of
an intravenously applied colouring agent indocyanine green (ICG) can be
analysed with the potential to identify malperfusion by little to no tissue
enhancement. Systemic sclerosis (SSc) is characterised by the presence of
digital ulcers reflecting progressive vasculopathy. The objective was to
investigate the potential of FOI in the detection of disturbed
microcirculation in the hands and fingers of patients with SSc and to link FOI
findings to clinical signs of ischemia such as digital ulcers and pitting
scars. Methods In this cross-sectional study, 63 patients with SSc and 26
healthy subjects were examined. FOI was performed in all 89 individuals and
compared to clinical data and capillaroscopic findings assembled for the SSc
cohort. Results Healthy subjects showed initial ICG signals in their
fingertips in 93.6%, SSc patients in 78.5% (limited SSc) and 43.2% (diffuse
SSc). Moreover, in SSc patients, FOI findings were significantly associated
with a late capillaroscopic pattern, disseminated SSc features, a diffuse SSc
subtype, and the presence of digital ulcers or pitting scars. Intra- and
inter-reader reliability for FOI amounted to κ = 0.786 and κ = 0.834,
respectively. Conclusions FOI is able to detect areas of reduced
microcirculation in patients with SSc with high association to capillaroscopic
findings. The results pave the way for future FOI investigations into its role
in the prediction of complications due to an impaired acral perfusion
