title: Visual Perception and Acuity of Hand Surgeons Using Loupes.
abstract: OBJECTIVE
  To assess the visual performance of Swiss hand surgeons in an environment similar to their workplace. The influence of Galilean (lenses only) and Keplerian loupes (lenses and prisms), the surgeon's age, and the credibility of a self-assessment of his or her own optical performance were evaluated.
  
  
  METHODS
  Sixty-three hand surgeons between 29 and 68 years of age with 70 loupes were included in the study (Galilean n = 35, Keplerian n = 35). The visual performance as surgeons was self-assessed on a modified visual analog scale and objectively measured with miniaturized visual tests in a simulated clinical setting. We evaluated the influence of the optical device by comparing Galilean and Keplerian loupes and the influence of the surgeon's age by comparing 2 subgroups: < 40 years and ≥ 40 years.
  
  
  RESULTS
  The correlation between self-assessment and objective visual performance was weak, with a Spearman rank correlation coefficient of 0.25. The near visual acuity with habitual optical aids showed considerable variability, with a range of 300% in the dimension of the smallest detected structure. The near visual acuity was significantly lower in the older group ≥ 40 years than in the younger group < 40 years with both Galilean and Keplerian loupes. Keplerian loupes allowed a significantly higher visual performance than Galilean loupes. Surgeons 40 years or older using Keplerian loupes had a similar visual acuity to surgeons younger than 40 years with Galilean loupes.
  
  
  CONCLUSIONS
  The magnified near vision of hand surgeons showed an important individual variability. Self-assessment was not a valuable instrument for surgeons to estimate their own near vision. Hand surgeons older than 40 years should use higher magnification loupes.
  
  
  METHODS
  Diagnostic III.
authors.affiliation: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Perrin
authors.affiliation: Department of Plastic and Hand Surgery, Inselspital, University of Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Romy
authors.initials: R
authors.lastname: Bregger
authors.affiliation: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse, Bern, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Lussi
authors.affiliation: Department of Plastic and Hand Surgery, Inselspital, University of Bern, Freiburgstrasse, Bern, Switzerland. Electronic address: esther.voegelin@insel.ch.
authors.forename: Esther
authors.initials: E
authors.lastname: Vögelin
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006225:Hand / Q000601:surgery; D006801:Humans; D007909:Lenses; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012647:Self-Assessment; D066231:Surgeons; D013557:Switzerland; D014785:Vision, Ocular; D014792:Visual Acuity
keywords: Loupes; acuity; hand surgeons; microsurgery; visual perception