title: In vivo data of epidermal thickness evaluated by optical coherence tomography: effects of age, gender, skin type, and anatomic site.
abstract: BACKGROUND
  The knowledge of epidermal thickness (ET) is of great significance in many areas of medical and biological research.
  
  
  OBJECTIVE
  We aimed to assess optical coherence tomography (OCT) in terms of precision, and to investigate the influence of several constitutional factors, such as age, gender, skin type, and anatomic site, on the mean ET using OCT in vivo.
  
  
  METHODS
  Eighty-three subjects were studied using OCT in vivo. Intra- and inter-day repeatability measurements were performed. The mean ET was assessed in six different body sites of young (20-40 years old) and old (60-80 years old) Caucasians, respectively. An ethnic group was included into the study.
  
  
  RESULTS
  OCT proved to be a precise technique in terms of repeatability and reproducibility as expressed in low coefficients of variation. Comparison of young and old Caucasians demonstrated a significant decrease of ET with age in all anatomic sites investigated. ET assessed in males and females did not significantly differ, except for forehead skin which is significantly thinner in old females than in males. ET observed in Caucasians did not significantly differ from ET measured in ethnic individuals. Anatomic sites insignificantly influenced ET on an inter-individual level. However, differences of ET between body sites on an intra-individual level are significant.
  
  
  CONCLUSIONS
  This was the first systematic in vivo study on ET investigating several influencing parameters of the epidermal dimension in a reasonable study sample by means of OCT. The results presented here may serve as ET reference data in a variety of clinical and experimental matters.
authors.affiliation: Department of Dermatology, Ruhr-University Bochum, Gudrunstr. 56, 44791 Bochum, Germany. t.gambichler@klinikum-bochum.de
authors.forename: Thilo
authors.initials: T
authors.lastname: Gambichler
authors.forename: Rebecca
authors.initials: R
authors.lastname: Matip
authors.forename: Georg
authors.initials: G
authors.lastname: Moussa
authors.forename: Peter
authors.initials: P
authors.lastname: Altmeyer
authors.forename: Klaus
authors.initials: K
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D004817:Epidermis / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012880:Skin Pigmentation; D041623:Tomography, Optical Coherence