title: [Reproducibility of measurement of ocular pulse amplitude and intraocular pressure using Smartlens].
abstract: BACKGROUND
  SmartLens (ODC Ophthalmic Development Company AG, Zürich) is a contact lens tonometer, which allows continuous registration of intraocular pressure (IOP) and ocular pulse amplitude (OPA) and simultaneous ophthalmoscopy. The purpose of this study was to evaluate the intra- and interobserver variability and reliability of intraocular pressure and ocular pulse amplitude measurements using SmartLens.
  
  
  METHODS
  To evaluate the intraobserver variability, intraocular pressure (IOP) and ocular pulse amplitude (OPA) were both measured 5 times in 10 healthy eyes by one observer. To evaluate the interobserver variability, intraocular pressure and ocular pulse amplitude were measured by 3 different observers in 10 healthy eyes. Data description is based on coefficients of variation (SD/mean in %), statistical inference on ANOVA-based reliability estimation.
  
  
  RESULTS
  The coefficient of the intraobserver variation was 9.57% for the IOP and 14.5% for the OPA (SD IOP: +/- 1.64 mmHg, SD OPA: +/- 0.39 mmHg). The coefficient of the interobserver variation with 5 replicate measurements was 10.16% for the IOP and 14% for the OPA (SD IOP: +/- 1.83 mmHg, SD OPA: +/- 0.4 mmHg). The interobserver reliability was 87% for the IOP and 86% for the OPA. One of the three observers obtained significantly higher IOP and OPA values.
  
  
  CONCLUSIONS
  SmartLens is a reasonably precise and reliable device for IOP as well as OPA measurements but the results were not found to be observer independent.
authors.affiliation: Universitäts-Augenklinik, Langenbeckstrasse 1, 55131 Mainz. Annette.Vogel@gmx.de
authors.forename: A
authors.initials: A
authors.lastname: Vogel
authors.forename: S
authors.initials: S
authors.lastname: Beck
authors.forename: O
authors.initials: O
authors.lastname: Schwenn
authors.forename: F
authors.initials: F
authors.lastname: Grus
authors.forename: F
authors.initials: F
authors.lastname: Krummenauer
authors.forename: N
authors.initials: N
authors.lastname: Pfeiffer
mesh_terms: D000704:Analysis of Variance; D003261:Contact Lenses; D005260:Female; D005901:Glaucoma / Q000175:diagnosis; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008962:Models, Theoretical; D015588:Observer Variation; D013997:Time Factors; D014065:Tonometry, Ocular / Q000295:instrumentation* / Q000379:methods