title: [An objective measure of ocular torsion: a new indirect ophthalmoscopy lens].
abstract: OBJECTIVE
  Ocular torsion can be measured by different means. While subjective methods are commonly used in ophthalmological practice, objective methods are time consuming and require expensive photographic equipment. The authors present a new ophthalmoscopic lens which allows a rapid and quantitative evaluation of cyclotropia.
  
  
  METHODS
  Objective measurement of the optic nerve head (ONH)-foveal angle was performed in 30 eyes of 15 normal volunteers. Results were compared, for each subject to those obtained when measuring ocular torsion by two subjective methods: double Maddox rod and dark red glass in front of Harms' tangent screen.
  
  
  RESULTS
  The new ophthalmoscopic lens showed a mean slight incyclotortion of 0.40 degrees +/- 0.20 (SEM) while Harms' tangent screen a mean slight excyclotortion of 0.12 degrees +/- 0.20 and double Maddox rod absence of torsion: 0.02 degrees +/- 0.20. No statistical difference was shown when comparing the three methods with Student paired T test.
  
  
  CONCLUSIONS
  The new ophthalmoscopic lens allows a rapid and quantitative evaluation of ocular torsion. Measurements can easily be performed during routine fundus examination by any practitioner.
authors.affiliation: Unité de Strabologie, Hôpital Ophtalmique Universitaire Jules Gonin, Lausanne.
authors.forename: E
authors.initials: E
authors.lastname: de Ancos
authors.forename: G
authors.initials: G
authors.lastname: Klainguti
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D007909:Lenses; D008297:Male; D008875:Middle Aged; D019721:Ophthalmoscopes; D009898:Optic Disk; D012016:Reference Values; D013285:Strabismus / Q000175:diagnosis*
vernacular_title: Mesure objective de la torsion oculaire: une nouvelle loupe d'ophtalmoscopie indirecte.