title: Accuracy of wavefront aberrometer refraction vs manifest refraction in cataract patients: impact of age, ametropia and visual function.
abstract: BACKGROUND
  To evaluate accuracy of WASCA wavefront aberrometry (WA) refraction in comparison to manifest refraction (MR) in an older population awaiting cataract surgery.
  
  
  METHODS
  Prospectively, refractive errors of 130 eyes were determined by WA and MR. Mean age was 65.9 (SD 11.81), corrected distance visual acuity (CDVA) averaged 0.20 logMar (SD 0.57), mean manifest sphere was 0.23 dioptres (D, SD 3.39) and manifest astigmatism amounted to -1.25 D (SD 1.21). For further analysis, refractive values were transformed into power vector components: spherical equivalent (SE), Jackson cross cylinder at 0° and 45° (J0 and J45). The 'limits of agreement' approach, regression analysis, correlation analysis, and ANOVA were applied and additionally compared to 28 healthy eyes (mean VA -0.1 logMAR) of a group of young subjects (mean age 33.9).
  
  
  RESULTS
  SE measures in myopia correlated highly between WA and MR (r = 0.917, p < .001). In hyperopia this correlation was moderately high (r = 0.800, p < .001). For all subjects, correlations between WA and MR for J0 and J45 were r = 0.742 (p < .001) and r = 0.760 (p < .001) respectively. WA measurements revealed larger agreement ranges with increasing myopia and astigmatism. Controlled for possible confounding variables of age, VA, and refractive state, no statistically significant effects were found. Across nearly all conditions, WA measured significantly higher myopic and astigmatic values than MR. Most effects were replicated in the reference group.
  
  
  CONCLUSIONS
  WA refraction can provide valuable information in previously under-researched conditions such as reduced VA (cataract-related), advanced age, and hyperopia. However, loss of optical media transparency will inherently reduce accuracy of WA. Further studies are needed to define cut-off values for automated wavefront quality grading and intra-operative application of WA in refractive surgery.
authors.affiliation: Klinik und Poliklinik fuer Augenheilkunde, Universitaetsklinikum Hamburg-Eppendorf, Haus W40, Martinistr. 52, 20246 Hamburg, Germany. j.huelle@uke.de
authors.forename: Jan O
authors.initials: JO
authors.lastname: Huelle
authors.forename: Toam
authors.initials: T
authors.lastname: Katz
authors.forename: Jan
authors.initials: J
authors.lastname: Draeger
authors.forename: Milena
authors.initials: M
authors.lastname: Pahlitzsch
authors.forename: Vasyl
authors.initials: V
authors.lastname: Druchkiv
authors.forename: Johannes
authors.initials: J
authors.lastname: Steinberg
authors.forename: Gisbert
authors.initials: G
authors.lastname: Richard
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Linke
mesh_terms: D057128:Aberrometry / Q000592:standards*; D000328:Adult; D000367:Age Factors; D000368:Aged; D002386:Cataract / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000503:physiopathology*; D015203:Reproducibility of Results; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*