title: Variability of Heidelberg Retina Tomograph parameters during exercise.
abstract: OBJECTIVE
  The purpose of this study was to determine whether exercise affects the stereometric parameters representing optic nerve head (ONH) topography.
  
  
  METHODS
  ONH topography, intraocular pressure (IOP) and blood pressure of 30 healthy volunteers were monitored before, during and after dynamic exercise raising systolic blood pressure by a minimum of 30 mmHg. Change in the stereometric ONH parameters was calculated.
  
  
  RESULTS
  IOP decreased and blood pressure increased during exercise, resulting in an increase in mean ocular perfusion pressure. Exercise was associated with an increase in variance in 17 of the 18 stereometric ONH parameters. The increase in variance was statistically significant in eight parameters, including rim area, cup/disc area ratio and cup shape measure. There was no statistically significant change in image quality. The absolute change from baseline in rim area, cup area, cup/disc area ratio, rim/disc area ratio and rim volume showed a statistically significant (p < 0.05) correlation with change in mean ocular perfusion pressure.
  
  
  CONCLUSIONS
  Exercise increases variability in stereometric ONH parameters. To avoid increased variance in the stereometric parameters, ONH imaging should be performed after allowing sufficient time to rest.
authors.affiliation: Department of Ophthalmology, University of Oulu, Oulu, Finland. ville.saarela@oulu.fi
authors.forename: Ville
authors.initials: V
authors.lastname: Saarela
authors.forename: Elina
authors.initials: E
authors.lastname: Ahvenvaara
authors.forename: Anja
authors.initials: A
authors.lastname: Tuulonen
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation / Q000592:standards*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D009898:Optic Disk / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D014054:Tomography; D055815:Young Adult