title: Customized Finite Element Modelling of the Human Cornea.
abstract: OBJECTIVE
  To construct patient-specific solid models of human cornea from ocular topographer data, to increase the accuracy of the biomechanical and optical estimate of the changes in refractive power and stress caused by photorefractive keratectomy (PRK).
  
  
  METHODS
  Corneal elevation maps of five human eyes were taken with a rotating Scheimpflug camera combined with a Placido disk before and after refractive surgery. Patient-specific solid models were created and discretized in finite elements to estimate the corneal strain and stress fields in preoperative and postoperative configurations and derive the refractive parameters of the cornea.
  
  
  RESULTS
  Patient-specific geometrical models of the cornea allow for the creation of personalized refractive maps at different levels of IOP. Thinned postoperative corneas show a higher stress gradient across the thickness and higher sensitivity of all geometrical and refractive parameters to the fluctuation of the IOP.
  
  
  CONCLUSIONS
  Patient-specific numerical models of the cornea can provide accurate quantitative information on the refractive properties of the cornea under different levels of IOP and describe the change of the stress state of the cornea due to refractive surgery (PRK). Patient-specific models can be used as indicators of feasibility before performing the surgery.
authors.affiliation: Dipartimento di Matematica, Politecnico di Milano, Milano, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Simonini
authors.affiliation: Dipartimento di Ingegneria Civile ed Ambientale, Politecnico di Milano, Milano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Pandolfi
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000601:surgery; D001696:Biomechanical Phenomena; D003315:Cornea / Q000033:anatomy & histology / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D007429:Intraocular Pressure; D008953:Models, Anatomic; D009216:Myopia / Q000601:surgery; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D012029:Refraction, Ocular; D013314:Stress, Mechanical