title: [Prospective Reliability Trial to Assess Inter and Intra Observer Reliability of Rebound Tonometry in the Eyes of Healthy Probands].
abstract: OBJECTIVE
  A prospective reliability trial was implemented to estimate the inter- and intraobserver reproducibility of iCare® rebound tonometry in healthy proband eyes.
  
  
  METHODS
  Three independent observers performed three replicate measurements, respectively, by means of the iCare®PRO rebound tonometry device in 20 eyes of 20 healthy probands. Two of these observers were medical doctors with an at least two years experience in ophthalmological patient care, the third observer was a study nurse with several years practice in applying ophthalmological diagnostic procedures. Each observer's replicate measurements were averaged and then compared by means of a global Friedman test for interobserver bias in the parallel rebound tonometry measurements at the 5 % significance level. In addition, variance component analysis was performed on the overall repeated measurement design to estimate the iCare® reliability coefficient [%] (100 % indicating total reproducibility in absence of any inter or intra observer bias).
  
  
  RESULTS
  The respective observers' median average measurements were 15.9 mmHg (interquartile range 15.1 to 17.5 mmHg) and 15.1 mmHg (14.3 to 15.6 mmHg) for the medical doctors, furthermore 16.8 mmHg (14.2 to 18.9 mmHg) for the study nurse; the averaged measurement series showed a significant interobserver bias (Friedman p = 0.006). Variance component analysis revealed an overall iCare® reliability of 35 % (95 % confidence interval 26 to 44 %).
  
  
  CONCLUSIONS
  In this repeated measurement design iCare® rebound tonometry measurements showed significant interobserver bias and thereby notably reduced overall reliability. In particular, the intraindividual measurement profiles showed a gradient towards smaller values during the 9 replicates' series; furthermore the study nurses' measurements showed notably increased variability. As a consequence the routine use of iCare® rebound tonometry must be critically discussed at least when being delegated to less experienced staff.
authors.affiliation: Institut für Medizinische Biometrie und Epidemiologie, Fakultät für Gesundheit der Universität Witten/Herdecke, Witten.
authors.forename: F
authors.initials: F
authors.lastname: Krummenauer
authors.affiliation: Institut für Medizinische Biometrie und Epidemiologie, Fakultät für Gesundheit der Universität Witten/Herdecke, Witten.
authors.forename: D
authors.initials: D
authors.lastname: Sagri
authors.affiliation: Forschungsbereich "Patientenorientierte Forschung für die Augenheilkunde", Augenklinik Mülheim/Ruhr.
authors.forename: B-B
authors.initials: BB
authors.lastname: Bestges
authors.affiliation: Forschungsbereich "Patientenorientierte Forschung für die Augenheilkunde", Augenklinik Mülheim/Ruhr.
authors.forename: C C
authors.initials: CC
authors.lastname: Lösche
mesh_terms: D000328:Adult; D002983:Clinical Competence / Q000706:statistics & numerical data*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008365:Manometry / Q000295:instrumentation* / Q000706:statistics & numerical data*; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity