Session Type: Abstract Submissions (ACR)
Background/Purpose: Optical coherence tomography (OCT) has been shown to be a quantitative reliable tool to assess skin involvement in Systemic Sclerosis (SSc) (1). However the sensitivity to change over-time has not been evaluated. The present study aimed to compare skin assessment by OCT over-time in patients with SSc.
Methods: We performed 24 OCT scans of dorsal forearms on 12 sites of analysis from 7 SSc patients (6 with diffuse, 1 with limited subset according to Le Roy et al; mean disease duration at baseline= 8 ± 2.3 years) at 0 and 24 months. Clinical skin involvement was assessed using the modified Rodnan skin score (mRss). Minimum and Maximum Optical Density (Min and Max OD) of the mean-A scans were calculated employing Matlab software as previously described (1). Comparison of the local mRss and Min and Max OD at the 2 time-points was performed by two-tailed paired t-test employing GraphPrism software.
Results: Five sites of analysis with local mRss=0 did not change over 24 months. Accordingly, both Min and Max OD showed only an average -1.81% and -2.31% change, respectively (p>0.05) (1). On the contrary, in 5 sites of analysis mRss improved by 2 points (two sites with local score “2” improved to “0”, three sites with local score of “3” improved to “1”). In these sites Min OD showed an increase of 29% (range=23-37%; p=0.0005) and Max OD of 29.8% (range=18-41%; p=0.0027). Furthermore, both Min and Max OD showed a trend forward a decrease (-3.54%, -5.41% respectively) at the 2 sites of analysis with worsening mRSS (one point increase) but the low sample size did not allow to perform a statistical evaluation.
Conclusion: Although preliminary for the low number of observations, this study provides the first evidence suggesting that OCT of the skin is sensitive to change over time and it changes consistently with mRss. Studies including a larger number of patients and sites of analysis with different grades of skin involvement and improvement/deterioriation of clinical score are needed to reach a definitive validation.
References: 1. Abignano et al. Ann Rheum Dis 2013.
L. A. Bissell,
Michelson Diagnostics Ltd,
M. H. Buch,
F. Del Galdo,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/longitudinal-assessment-of-scleroderma-skin-by-optical-coherence-tomography-preliminary-validation-of-sensitivity-to-change-over-time/