title: SyntEyes: A Higher-Order Statistical Eye Model for Healthy Eyes.
abstract: OBJECTIVE
  Stochastic eye models are a method to generate random biometry data with the variability found in the general population for use in optical calculations. This work improves the accuracy of a previous model by including the higher-order shape parameters of the cornea.
  
  
  METHODS
  The right eye biometry of 312 subjects (40.8 ± 11.0 years of age) were measured with an autorefractometer, a Scheimpflug camera, an optical biometer, and a ray tracing aberrometer. The corneal shape parameters, exported as Zernike coefficients, were converted to eigenvectors for dimensional reduction. The remaining 18 parameters were modeled as a sum of two multivariate Gaussians, from which an unlimited number of synthetic data sets (SyntEyes) were generated. After conversion back to Zernike coefficients, the data were introduced into ray tracing software.
  
  
  RESULTS
  The mean values of nearly all SyntEyes parameters were statistically equal to those of the original data (two one-sided t-test, P > 0.05/109, Bonferroni correction). The variability of the SyntEyes parameters was similar to the original data for most important shape parameters and intraocular distances (F-test, P < 0.05/109), but significantly lower for the higher-order shape parameters (F-test, P > 0.05/109). The same was seen for the correlations between higher-order shape parameters. After applying simulated cataract or refractive surgery to the SyntEyes model, a very close resemblance to previously published clinical outcome data was seen.
  
  
  CONCLUSIONS
  The SyntEyes model produces synthetic biometry that closely resembles clinically measured data, including the normal biological variations in the general population.
authors.affiliation: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium 2Department of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium.
authors.forename: Jos J
authors.initials: JJ
authors.lastname: Rozema
authors.affiliation: Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciones Científicas and Universidad de Zaragoza, Facultad de Ciencias, Zaragoza, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodriguez
authors.affiliation: Instituto de Ciencia de Materiales de Aragón, Consejo Superior de Investigaciones Científicas and Universidad de Zaragoza, Facultad de Ciencias, Zaragoza, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Navarro
authors.affiliation: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium 2Department of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium.
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Tassignon
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000502:physiology*; D001699:Biometry / Q000379:methods*; D003315:Cornea / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D055095:Optics and Photonics / Q000706:statistics & numerical data*; D012016:Reference Values; D012029:Refraction, Ocular / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult