title: [Comparative study of the biometric measurements made by immersion and contact techniques].
abstract: OBJECTIVE
  To compare clinical biometric findings between measurements of immersion technique and contact technique.
  
  
  METHODS
  Axial length was measured by A-scan in 120 medical examinations in 60 patients with cataract using a non-contact (immersion) and a contact technique in paired-samples by ultrasound.
  
  
  RESULTS
  The mean axial length was found to be 23.19 mm (SD 1.32) with the immersion technique and 22.93 mm (SD 1.32) with the contact technique, using the same transducer probe. The difference of 0.255 mm (SD 0.3) was significant at the 0.01 level. The difference should be taken into account when evaluating the accuracy of IOL calculation. The mean standard deviation between recurrent measures in same eye was found to be 0.04 with the immersion technique and 0.19 with the contact technique. The difference of 0.15 was significant at the 0.01 level. The difference should be taken into account when evaluating the accuracy of reproductivity of technique examination.
  
  
  CONCLUSIONS
  These data provide benchmark information that can be used to monitor clinical practice and to perform others studies.
authors.affiliation: Serviço de Retina, Hospital Banco de Olhos de Porto Alegre, Rua Coronel Bordini 414, Porto Alegre, RS, CEP 90440-002 Brazil. centrodeolhos@msn.com
authors.forename: Airton Leite
authors.initials: AL
authors.lastname: Kronbauer
authors.forename: Fernando Leite
authors.initials: FL
authors.lastname: Kronbauer
authors.forename: Cláudia Leite
authors.initials: CL
authors.lastname: Kronbauer
mesh_terms: D001699:Biometry / Q000379:methods; D002386:Cataract / Q000000981:diagnostic imaging*; D004812:Epidemiologic Methods; D005123:Eye / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D011300:Preoperative Care; D011446:Prospective Studies; D015203:Reproducibility of Results; D014463:Ultrasonography