title: Prevalence of corneal astigmatism before cataract surgery.
abstract: OBJECTIVE
  To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates.
  
  
  METHODS
  University of Valencia, Valencia, Spain.
  
  
  METHODS
  Refractive and keratometric values were measured before surgery in patients having cataract extraction. Descriptive statistics of refractive and keratometric cylinder data were analyzed and correlated by age ranges.
  
  
  RESULTS
  Refractive and keratometric data from 4,540 eyes of 2,415 patients (mean age 60.59 years +/- 9.87 [SD]; range 32 to 87 years) differed significantly when the patients were divided into 10-year subsets. There was a trend toward less negative corneal astigmatism values, except the steepest corneal radius and the J(45) vector component, in older groups (Kruskal-Wallis, P<.01). In 13.2% of eyes, no corneal astigmatism was present; in 64.4%, corneal astigmatism was between 0.25 and 1.25 diopters (D) and in 22.2%, it was 1.50 D or higher.
  
  
  CONCLUSIONS
  Corneal astigmatism less than 1.25 D was present in most cataract surgery candidates; it was higher in about 22%, with slight differences between the various age ranges. This information is useful for intraocular lens (IOL) manufacturers to evaluate which age ranges concentrate the parameters most frequently needed in sphere and cylinder powers and for surgeons to evaluate which IOLs provide the most effective power range.
authors.affiliation: Optometry Research Group, Optics Department, University of Valencia, Valencia, Spain. teresa.ferrer@uv.es
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrer-Blasco
authors.forename: Robert
authors.initials: R
authors.lastname: Montés-Micó
authors.forename: Sofia C
authors.initials: SC
authors.lastname: Peixoto-de-Matos
authors.forename: José M
authors.initials: JM
authors.lastname: González-Méijome
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cerviño
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis / Q000453:epidemiology*; D002387:Cataract Extraction; D003316:Corneal Diseases / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D013030:Spain / Q000453:epidemiology