Optical Coherence Tomography: The First Quantitative Imaging Biomarker for Scleroderma

Using the VivoSight OCT scanner, manufactured in the UK by Michelson Diagnostics Ltd, scientists at the Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds have developed the first quantitative imaging biomarker for skin involvement in Scleroderma.

Scleroderma or Systemic Sclerosis (SSc) is a serious type of autoimmune disorder affecting approximately 1 in 10,000 people. It is a progressive disease that involves skin and internal organs by determining fibrosis, vasculopathy and immune system activation.

The extent and severity of skin fibrosis is an important prognostic indicator of Scleroderma and often a primary endpoint in clinical trials to assess treatment efficacy. Skin fibrosis is currently assessed using a clinical semi-quantitative method called “modified Rodnan skin score”, based on clinical palpation in 17 body areas using a 0 to 3 scale.

To develop their quantitative model, the group in Leeds led by Dr Francesco Del Galdo performed 458 OCT scans on 21 SSc patients, 1 morphea and 22 healthy controls, comparing the results with clinical assessment and histology.

Their results were recently published on the “Annals of the Rheumatic Diseases”1 Journal and also highlighted in this month issue of Nature Reviews Rheumatology2. The authors conclude in their original work: “OCT of the skin could offer a feasible and reliable quantitative outcome measure in SSc. Studies determining OCT sensitivity to change over time and its role in defining skin vasculopathy may pave the way to defining OCT as a valuable imaging biomarker in SSc.”

The VivoSight OCT scanner enables clinicians to non-invasively image 1-2 mm beneath the surface of the skin with a clarity and accuracy previously unavailable. The research team in Leeds evaluated images captured of the dermal-epidermal junction and dermis using specially designed image processing algorithms. The significant correlation of the optical density with skin thickness and the excellent inter and intraobserver reliability of the technique suggests that an OCT-based algorithm is an accurate and reliable tool to quantify skin involvement in Scleroderma.

The study’s lead author Dr Giuseppina Abignano, who was recently awarded by the British Society for Rheumatology for her “illuminating research” with VivoSight said;

“Our study is the first in the field proposing a quantitative imaging biomarker of skin fibrosis in Scleroderma. We are currently undertaking a longitudinal study to test the sensitivity of the OCT based algorithm. These studies will tell us whether we can use OCT to determine changes in skin fibrosis over time and therefore use it as outcome measure in clinical trials and in clinical management. This is a very important step toward improving the prognosis for people who suffer from this devastating disease.”