title: Clinical utility of spectral analysis of intraocular pressure pulse wave.
abstract: BACKGROUND
  To evaluate the clinical utility of spectral analysis of intraocular pressure pulse wave in healthy eyes of a control group (CG), patients having glaucomatous optic disc appearance or ocular hypertension, and patients with primary open angle glaucoma or primary angle closure glaucoma.
  
  
  METHODS
  This is a prospective study that enrolled 296 patients from a single glaucoma clinic. Age matched CG consisted of 62 individuals. Subjects underwent comprehensive clinical diagnostic procedures including intraocular pressure (IOP) measurement with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT). DCT time series were analyzed with custom written software that included signal preprocessing, filtering and spectral analysis. An amplitude and energy content analysis, which takes into account non-stationarity of signals but also provides methodology that is independent of IOP and ocular pulse amplitude (OPA) levels, was applied. Spectral content up to the 6th harmonic of the pressure pulse wave was considered. Statistical analyses included descriptive statistics, normality test, and a multicomparison of medians for independent groups using Kruskal-Wallis test.
  
  
  RESULTS
  GAT IOP showed statistical significance (Kruskal-Willis test p < 0.05) for three out of 10 considered multiple comparisons, DCT IOP and OPA showed statistically significant results in five and seven cases, respectively. Changes in heart rate and central corneal thickness between the groups were statistically significant in two cases. None of the above parameters showed statistically significant differences between CG and the suspects with glaucomatous optic disc appearance (GODA). On the other hand, spectral analysis showed statistically significant differences for that case.
  
  
  CONCLUSIONS
  Spectral analysis of the DCT signals was the only method showing statistically significant differences between healthy eyes and those of GODA suspects.
authors.affiliation: Faculty of Materials, Strength and Welding, Wroclaw University of Technology, Smoluchowskiego 25, 50-372 Wroclaw, Poland. magdalena.asejczyk@pwr.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Asejczyk-Widlicka
authors.forename: Patrycja
authors.initials: P
authors.lastname: Krzyżanowska-Berkowska
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kowalska
authors.forename: D Robert
authors.initials: DR
authors.lastname: Iskander
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology*; D011446:Prospective Studies; D063177:Pulse Wave Analysis / Q000379:methods*