Imaging of collagen deposition disorders using optical coherence tomography

BackgroundCollagen deposition disorders such as hypertrophic scars, keloids and scleroderma can be associated with significant stigma and embarrassment. These disorders often constitute considerable impairment to quality of life, with treatment posing to be a substantial challenge. Optical coherence tomography (OCT) provides a non-invasive, easily applicable bedside optical imaging method for assessment of the skin. It is hypothesized that OCT imaging may be useful in assessing fibrosis to avoid additional biopsies that could potentially worsen the scarring. MethodThirty-three patients with ordinary scars, hypertrophic scars, keloid scarring, lichen sclerosus et atrophicus and localized or systemic scleroderma were recruited for this pilot study. Affected tissue and adjacent healthy skin were scanned using OCT and digitally photographed. Density measurements were performed in ImageJ on OCT images from scleroderma patients, both systemic and morphea (10 patients), keloid patients (10 patients) and healthy skin adjacent to keloids (10 patients). ResultsOCT images of scarring diseases showed varying degrees of disruption to the skin architecture. OCT characteristics were identified for each lesion type. Hypertrophic scars displayed an increased vascularity and signal-rich bands correlating to excessive collagen deposition. Keloids depicted a disarray of hyper-reflective areas primarily located in the upper dermis. Additionally, the dermis displayed a heterogeneous morphology without indications of any vascular supply or lymphatic network. In contrast to keloids, scleroderma displayed a more cohesive backscattering indicating a difference in density of collagen or other dermal structures. OCT images demonstrated no significant differences between mean density measurements in OCT images of scleroderma, keloid and healthy skin (P=0.07). ConclusionThe OCT imaging appears to identify different scarring mechanisms, and therefore be of potential use in the assessment of outcomes following non-invasive therapy of e.g. early or progressive lesions.