title: Chen's Double Eyelid Fold Ratio.
abstract: BACKGROUND
  Double eyelidplasty can construct palpebral folds and enhance beauty perception for Asians with single eyelids. A new palpebral parameter for the quantitative interpretation of surgical outcomes is proposed on the basis of a photometric study of the altered proportions of Asian eyes after double eyelid operation.
  
  
  METHODS
  A total of 100 Asian adults with single upper eyelids who were satisfied with the enlarged eyes by operation were included in the study. A retrospective measurement of palpebral parameters in the frontal profile both preoperatively and 6 months postoperatively was performed. The proportions of various parameters in the eyebrow-eye aesthetic unit were calculated and analyzed.
  
  
  RESULTS
  Double eyelidplasty can augment the vertical dimension of palpebral fissure by 27.9% increase on average. The vertical ratio of palpebral fissure to the eyebrow-eye unit is augmented by 34.4% increase. The vertical ratio of the subunit below double eyelid fold peak to the unit is augmented by 82.6% increase.
  
  
  CONCLUSIONS
  Double eyelidplasty can substantially enlarge the vertical dimensions of the eyes of Asians with single eyelids. The eyes are perceived to be larger because of the visually assimilated illusion of the superimposed eyelid fold and the relative proportions of the eyebrow-eye unit. The authors propose using a vertical ratio of the subunit below double eyelid fold peak in the eyebrow-eye unit to measure the visually perceived proportion of the eye in the unit. This ratio can be applied clinically for a quantitative evaluation of the surgical outcome after double eyelidplasty.
authors.affiliation: Regent Aesthetic Surgery Clinic, Taipei, Taiwan; and Department of Plastic Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chen-Chia
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Regent Aesthetic Surgery Clinic, Taipei, Taiwan; and Department of Plastic Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Hao-Chih
authors.initials: HC
authors.lastname: Tai
authors.affiliation: Regent Aesthetic Surgery Clinic, Taipei, Taiwan; and Department of Plastic Surgery, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chien-Lin
authors.initials: CL
authors.lastname: Huang