Table 2.

Summary of Studies Investigating the use of OCT to Image Skin Fibrosis

Authors	Study Aim	Population Characteristics	Findings	Limitations
Normal Skin
Mogensen et al [19]	To describe normal skin collagen morphology using PS-OCT imaging	Healthy volunteers aged 0.5–59 years; (n = 20); examined forehead, ear lobe, nose, cheek, chin, back of the neck, chest, hands, arms and calf	PS-OCT images showed characteristic structures due to the birefringence differences between epidermis, papillary, and reticular dermis	Small proportion of children relative to adults in the study
Pierce et al [25]	To measure anatomic variations in birefringence using PS-OCT	Healthy volunteers aged 24–35 years; (n = 5); examined lower back, temple, and hand	Mean phase retardation highest for skin of the lower back and lowest for skin of the temple	Study limited to male patients; small sample size
Pircher et al [27]	To use phase resolved PSOCT to investigate polarization properties of different regions of human skin in vivo	Healthy volunteers; (n not specified); examined fingertip and hand	3-D PS-OCT has potential to increase contrast and quantify retardation and orientation of birefringent structures in skin	Selected skin regions examined
Yasuno et al [37]	To investigate normal skin birefringence using PS-OCT	Healthy volunteers	PS-OCT successfully revealed the birefringent nature of human skin tissue	Limited information on volunteers
Fibrosis
Abignano et al [1]	To determine if SS-OCT could offer a potential sensitive imaging biomarker to assess and quantify skin fibrosis	Systemic sclerosis patients with mean age of 54 years; (n = 21); examined fingers, hands, and forearms	Systemic sclerosis affected skin displayed consistent decrease of optical density in the papillary dermis, this directly correlated with mRSS score	Selected skin regions scanned; Only two patients underwent skin biopsies and from sites with MRSS of 3
Kunzi-Rapp et al [14]	Use OCT to evaluate new collagen synthesis after scar treatment with the Er:YAG laser	Post-traumatic and acne scar patients aged 12–39 years; (n = 12); examined face and extremities	OCT demonstrated was the production of new collagen bundles after scar treatment with the Er:YAG laser	N/A – OCT was not the main goal of study but rather used in assessment
Liew et al [16]	To investigate the utility of OCT to quantify vascularity in hypertrophic scars	Hypertrophic scar patients with mean age of 32 years; (n = 8); examined burn scar sites	Increase in mean density of vasculature in hypertrophic scar tissues (38%) when compared with normal, unscarred skin (22%); proliferation of larger vessels	Pilot study – small sample size; scans acquired in the severely affected areas of each scar
Pierce MC, Strasswimmer J et al [26]	To demonstrate the capability of OCT in detecting features of skin fibrosis	Fibrotic scar patient; (n = 1); examined hand	PS-OCT imaging quantitatively demonstrated polarization differences between normal skin and the fibrotic site	Fibrosis examination restricted to the hand; small sample size