title: Age is highly associated with stereo blindness among surgeons: a cross-sectional study.
abstract: The prevalence of stereo blindness in the general population varies greatly within a range of 1-30 %. Stereo vision adds an extra dimension to aid depth perception and gives a binocular advantage in task completion. Lack of depth perception may lower surgical performance, potentially affecting surgical outcome. 3D laparoscopy offers stereoscopic vision of the operative field to improve depth perception and is being introduced to several surgical specialties; however, a normal stereo vision is a prerequisite. The aim of this study was to establish the prevalence of stereo blindness among surgeons in the field of general surgery, gynecology, and urology as these are potential users of 3D laparoscopy.
  
  
  
  The study was conducted according to the STROBE guidelines for cross-sectional studies. Medical doctors from the department of general surgery, gynecology, and urology were recruited and stereo tested by the use of the Random Dot E stereo test. Upon stereo testing, a demographic questionnaire was completed. Multivariate logistic regression analysis was employed to assess the association between stereo blindness and the variables resulting from the univariate analysis.
  
  
  
  Three hundred medical doctors completed the study. Of these 9.7 % were stereo blind. There were 47 % women and 53 % men, aged 25-71 years. General surgery was represented with 64 % of the participants, gynecology with 26 %, and urology with 10 %. Age (OR 5.6; CI 1.7-18.9; P = 0.005) and not being aware of having any vision anomaly in need for correction (OR 4; CI 1.4-11.4; P = 0.010) were significantly associated with stereo blindness.
  
  
  
  Approximately one in ten medical doctors in general surgery, gynecology, and urology were stereo blind with an increasing prevalence with age. This is relevant since stereo blind surgeons will not benefit from the implementation of 3D laparoscopy.
authors.affiliation: Center for Perioperative Optimization (CPO), Department of Surgery D, University of Copenhagen, 2730, Herlev, Denmark. sayakafergo@hotmail.com.
authors.forename: Charlotte
authors.identifier: 0000-0001-6014-5103
authors.initials: C
authors.lastname: Fergo
authors.affiliation: Department of Surgery, Koege Sygehus, 4600, Koege, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Burcharth
authors.affiliation: Department of Surgery, Hvidovre Hospital, University of Copenhagen, 2650, Hvidovre, Denmark.
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Pommergaard
authors.affiliation: Center for Perioperative Optimization (CPO), Department of Surgery D, University of Copenhagen, 2730, Herlev, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D003867:Depth Perception; D005260:Female; D006176:Gynecology; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D066231:Surgeons; D000072178:Urologists; D014786:Vision Disorders / Q000453:epidemiology*; D014787:Vision Tests
keywords: 3D laparoscopy; Binocular; Minimally invasive surgery; Stereo blindness; Stereopsis