Optical coherence tomography (OCT) of collagen in normal skin and skin fibrosis

Abstract

Optical coherence tomography (OCT) is a non-invasive imaging modality that is transforming clinical diagnosis in dermatology and other medical fields. OCT provides a cross-sectional evaluation of the epidermis and dermis and allows in vivo imaging of skin collagen. Upregulated collagen content is a key feature of fibrotic skin diseases. These diseases are often managed by the practitioner’s subjective assessment of disease severity and response to therapies. The purpose of this review is to provide an overview of the principles of OCT and present available evidence on the ability of OCT to image skin collagen in vivo for the diagnosis and management of diseases characterized by skin fibrosis. We review OCT studies that characterize the collagen content in normal skin and fibrotic skin diseases including systemic sclerosis and hypertrophic scars secondary to burn, trauma, and other injury. We also highlight several limitations of OCT and suggest enhancements to improve OCT imaging of skin fibrosis. We conclude that OCT imaging has the potential to serve as an objective, non-invasive measure of collagen’s status and disease progression for use in both research trials and clinical practice. The future use of OCT imagining as a quantitative imaging biomarker of fibrosis will help identify fibrosis and facilitate clinical examination in monitoring response to treatment longitudinally without relying on serial biopsies. The use of OCT technology for quantification of fibrosis is in the formative stages and we foresee tremendous growth potential, similar to the ultrasound development paradigm that evolved over the past 30 years.

Optical Coherence Tomography Imaging of Normal, Chronologically Aged, Photoaged and Photodamaged Skin

“…Furthermore, OCT’s ability to quickly provide visual and quantitative analyses of skin collagen content holds tremendous potential as a platform to assist in overcoming teledermatology’s tactile limitations when examining patients. 28 …”

“…5,27 Tissues with increased levels of collagen content, such as skin scarring and fibrosis, rapidly change the polarization state of light and have high phase retardation rates; tissues with decreased collagen content, such as photoaged or photodamaged skin, slowly change the polarization state of light and have low phase retardation rates. 28 …”

Optical coherence tomography angiography monitors human cutaneous wound healing over time

“…Here, this tightening also coincided with the appearance of bright structural features. The bright tissue surrounding the contracting wound is thought to be a feature of enhanced collagen deposition (66), which at this stage serves two purposes: to provide structural strength and facilitate the migration of various cell types responsible for wound healing (67,68). This ultimately results in high levels of collagen with relatively low tensile strength, however (69); hence, later remodeling.…”

Dynamic Optical Coherence Tomography in Dermatology

“…After early inflammatory stages, the vasculature is affected [31,32,33,34]. The blood vessels are rarefied, causing necrosis of the fingertips due to ischaemia.…”