title: An objective photographic analysis of ocular oblique muscle dysfunction.
abstract: OBJECTIVE
  To develop a new objective method for measuring ocular oblique muscle dysfunction.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Twelve healthy volunteers and 27 patients with oblique muscle overaction or underaction in at least 1 eye were included. The corneal contour in 9-gaze photographs was transcribed into an ellipse. A newly developed simulating program depicted the corneal contour as the eyes moved, and graded oblique muscle dysfunction by analyzing the angular difference between the 2 eyes. An angular difference of 5 degrees was defined as 1 unit of overaction or underaction. To verify the accuracy of the method, a masked observer compared the photographic analysis with goniometric readings in the model eye and magnetic search coil recordings in healthy volunteers. The diagnostic accuracy of the photographic analysis was compared with the clinical gradings of patients with oblique muscle overaction or underaction.
  
  
  RESULTS
  There was no statistical difference between photographic analysis and goniometric readings of the model eye. Bland-Altman plots showed that there was no overall tendency for the photographic analysis to differ from the scleral search coil values, and the difference fell mostly within ±7 degrees. There was a good correlation between the photographic analysis and the clinical grading of oblique muscle dysfunction (R(2) = 0.618; P < .001). The sensitivity and specificity for detecting oblique muscle overaction were 90.2% and 88.1%, respectively, whereas those for detecting underaction were 81.5% and 80.2%, respectively.
  
  
  CONCLUSIONS
  A newly developed photographic analysis could provide an objective and accurate means of evaluating ocular oblique muscle dysfunction.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Chang Ki
authors.initials: CK
authors.lastname: Yoon
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Yang
authors.affiliation: Department of Neurology Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Ji-Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea. Electronic address: hjm@snu.ac.kr.
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology* / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D010781:Photography; D011446:Prospective Studies; D015203:Reproducibility of Results; D013285:Strabismus / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D015348:Vision, Binocular; D014792:Visual Acuity; D055815:Young Adult