title: Computer modeling of visual impairment caused by intraocular lens misalignment.
abstract: OBJECTIVE
  To evaluate a computer program to modulate the visual impairment caused by intraocular lens (IOL) misalignment and visualize results obtained by numerical calculations.
  
  
  METHODS
  Department of Ophthalmology, Medical Faculty of Charles University, Prague, Czech Republic.
  
  
  METHODS
  The optic imagery of a Landolt circle was calculated using a ray-tracing computer program. Visual aberrations resulting from a decentered and/or tilted IOL were studied using this program and compared with theoretical calculations.
  
  
  RESULTS
  The IOL decentration and/or tilt shifted the postoperative refractive errors toward myopia and astigmatism (oblique). The combination of IOL decentration and tilt produced a refractive error that depended on the relationship between the geometrical axes of the decentration and tilt. The refractive error can be enhanced or diminished depending on the relationship of these axes.
  
  
  CONCLUSIONS
  These findings verify the results calculated by paraxial vergence equations. A ray-tracing program simulated the optic imagery for various kinds of IOL misalignment and IOL optic properties.
authors.affiliation: Department of Ophthalmology, Charles University, Prague, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Korynta
authors.forename: J
authors.initials: J
authors.lastname: Bok
authors.forename: J
authors.initials: J
authors.lastname: Cendelin
authors.forename: K
authors.initials: K
authors.lastname: Michalova
mesh_terms: D001251:Astigmatism / Q000209:etiology; D003198:Computer Simulation; D005548:Foreign-Body Migration / Q000150:complications*; D006801:Humans; D007910:Lenses, Intraocular / Q000009:adverse effects*; D008954:Models, Biological; D009216:Myopia / Q000209:etiology; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology