title: Topographic analysis of eyelid position using digital image processing software.
abstract: OBJECTIVE
  To propose a novel analysis technique for objective quantification of topographic eyelid position with an algorithmatically calculated scheme and to determine its feasibility.
  
  
  METHODS
  One hundred normal eyelids from 100 patients were segmented using a graph cut algorithm, and 11 shape features of eyelids were semi-automatically quantified using in-house software. To evaluate the intra- and inter-examiner reliability of this software, intra-class correlation coefficients (ICCs) were used. To evaluate the diagnostic value of this scheme, the correlations between semi-automatic and manual measurements of margin reflex distance 1 (MRD1) and margin reflex distance 2 (MRD2) were analysed using a Bland-Altman analysis. To determine the degree of agreement according to manual MRD length, the relationship between the variance of semi-automatic measurements and the manual measurements was evaluated using linear regression.
  
  
  RESULTS
  Intra- and inter-examiner reliability were excellent, with ICCs ranging from 0.913 to 0.980 in 11 shape features including MRD1, MRD2, palpebral fissure, lid perimeter, upper and lower lid lengths, roundness, total area, and medial, central, and lateral areas. The correlations between semi-automatic and manual MRDs were also excellent, with better correlation in MRD1 than in MRD2 (R = 0.893 and 0.823, respectively). In addition, significant positive relationships were observed between the variance and the length of MRD1 and 2; the longer the MRD length, the more the variance.
  
  
  CONCLUSIONS
  The proposed novel optimized integrative scheme, which is shown to have high repeatability and reproducibility, is useful for topographic analysis of eyelid position.
authors.affiliation: Department of Ophthalmology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Yeoun Sook
authors.initials: YS
authors.lastname: Chun
authors.affiliation: Department of Ophthalmology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Hong Hyun
authors.initials: HH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Kyung Hee University College of Medicine, Kyung Hee University Hospital, Seoul, Korea.
authors.forename: In Ki
authors.initials: IK
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Nam Ju
authors.initials: NJ
authors.lastname: Moon
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.|Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Jeong Kyu
authors.initials: JK
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D019882:Blepharoplasty / Q000379:methods; D005143:Eyelids / Q000000981:diagnostic imaging* / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000379:methods; D012372:ROC Curve; D015203:Reproducibility of Results; D012984:Software; D055815:Young Adult
keywords: digital image analysis; eyelid; repeatability; reproducibility