title: Incidence of lower eyelid asymmetry: an anthropometric analysis of 204 patients.
abstract: BACKGROUND
  To avoid complications and improve patient satisfaction with lower lid blepharoplasty, a precise assessment of any preoperative eyelid asymmetry is essential.
  
  
  OBJECTIVE
  The authors describe a method of assessing preoperative eyelid asymmetry through readily available software and classifying the resulting measurements.
  
  
  METHODS
  Digital images of 204 patients were analyzed using Photoshop CS3 Extended software (Adobe Systems, San Jose, California). The left eye was superimposed over the right eye using layers in the software program, and the lower eyelid margin and axis were outlined to obtain a diagram with the superimposed outlines of both eyes. Several measurements (ie, lateral canthal height, lower eyelid margin length and axis angle, and lower palpebral fissure surface area) were obtained for each patient. Differences between the right and left eyelids were recorded, and these data were compared between patients.
  
  
  RESULTS
  Of the 204 patients studied, 184 (90.2%) had some degree of asymmetry. Most (118; 64.13%) presented with the right lower eyelid at a more inferior position than the left (R-), while 66 (35.87%) presented with the right lower eyelid at a higher position than the left (R+), a difference that was highly significant (P < .001).
  
  
  CONCLUSIONS
  This software is a powerful and precise tool to evaluate and measure eyelid asymmetries. The use of this method showed a large degree of eyelid asymmetry preoperatively (more than 90%), which proves the importance of detecting and adequately analyzing this condition prior to surgery. The authors' simple method may be an important adjunct to obtaining optimal results in patients who seek eyelid surgery.
authors.affiliation: Complutense University of Madrid and Plastic and Reconstructive Surgery Department, Doce de Octubre University Hospital, Madrid, Spain. fgbravo@ruber.es
authors.forename: Francisco G
authors.initials: FG
authors.lastname: Bravo
authors.forename: Matias
authors.initials: M
authors.lastname: Kufeke
authors.forename: David
authors.initials: D
authors.lastname: Pascual
mesh_terms: D000328:Adult; D059925:Anatomic Landmarks; D000886:Anthropometry / Q000379:methods*; D019882:Blepharoplasty / Q000009:adverse effects; D016009:Chi-Square Distribution; D004954:Esthetics; D005143:Eyelids / Q000033:anatomy & histology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D017060:Patient Satisfaction; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control; D012984:Software; D016896:Treatment Outcome; D055815:Young Adult
keywords: anthropometric analysis; asymmetry; blepharoplasty; digital imaging; eyelids; oculoplastic surgery