title: Morphological skin ageing criteria by multiphoton laser scanning tomography: non-invasive in vivo scoring of the dermal fibre network.
abstract: BACKGROUND
  Morphological changes in the dermal collagen and elastin fibre network are characteristic for skin ageing and for pathological skin conditions of the dermis.
  
  
  OBJECTIVE
  To characterize pathological and physiological conditions by multiphoton laser scanning tomography (MLT) in vivo, it is necessary to investigate and identify morphological alterations related to ageing.
  
  
  METHODS
  In vivo MLT was used to image two-photon excited autofluorescence (AF) and second harmonics generation (SHG) in human dermis of 18 volunteers of different ages. Criteria for the evaluation of age-dependent morphological changes in MLT images were fibre tension and morphology, network pattern, clot formation and image homogeneity. These criteria were weighted and a score was calculated.
  
  
  RESULTS
  The resulting MLT-based Dermis Morphology Score is correlated with age (R2 = -0.90) and with the previously published SHG to AF Ageing Index of Dermis (R2 = 0.66). The two groups of young (age 21-38) and old (age 66-84) volunteers showed a significant difference in MLT score values (P < 0.001).
  
  
  CONCLUSIONS
  We could demonstrate an in vivo relationship between morphological characteristics of human dermis assessed by MLT and age. The present score allows the semi-quantitative evaluation of specific morphological changes of the dermal fibre network in ageing skin by in vivo AF and SHG imaging. This method will be useful for diagnostics of pathological conditions and their differentiation from ageing effects.
authors.affiliation: Department of Dermatology and Allergology, Friedrich Schiller University, Jena, Germany.
authors.forename: Martin Johannes
authors.initials: MJ
authors.lastname: Koehler
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hahn
authors.forename: Anja
authors.initials: A
authors.lastname: Preller
authors.forename: Peter
authors.initials: P
authors.lastname: Elsner
authors.forename: Mirjana
authors.initials: M
authors.lastname: Ziemer
authors.forename: Andrea
authors.initials: A
authors.lastname: Bauer
authors.forename: Karsten
authors.initials: K
authors.lastname: König
authors.forename: Rainer
authors.initials: R
authors.lastname: Bückle
authors.forename: Joachim W
authors.initials: JW
authors.lastname: Fluhr
authors.forename: Martin
authors.initials: M
authors.lastname: Kaatz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003094:Collagen; D020405:Dermis / Q000473:pathology*; D046169:Dermoscopy / Q000379:methods*; D004549:Elastin; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D016014:Linear Models; D008297:Male; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D012016:Reference Values; D015595:Skin Aging / Q000473:pathology*; D012871:Skin Diseases / Q000175:diagnosis; D014054:Tomography / Q000379:methods*
chemical_list: D003094:Collagen; D004549:Elastin