title: Five-year refractive changes in an adult population: Reykjavik Eye Study.
abstract: OBJECTIVE
  To study refractive changes over the course of 5 years in citizens of Reykjavik 50 years and older at baseline.
  
  
  METHODS
  The cohort was a population-based random sample of citizens 50 years and older. Eight hundred forty-six of the 958 survivors (88.2%) underwent a 5-year follow-up examination. Refraction and keratometry were performed using a Nidek (Gamagori, Japan) ARK 900 autorefractor keratometer. Typing and grading of lens opacification was carried out using Scheimpflug slit-lamp and retroilluminated images (Nidek EAS 1000), and axial length was measured by Nidek Echoscan 800.
  
  
  RESULTS
  Seven hundred fifty-seven right eyes were available for refraction analysis. In the 50- to 59-year age group and the 60- to 69-year age group at baseline, there was a hyperopic shift of 0.41 diopters (D) and 0.34 D, respectively, during the 5 years. There was a 0.02-D myopic shift for those 70 years of age and older at baseline during the same period. Considering all right eyes, there was a hyperopic shift of +0.29 D over the 5 years, whereas eyes with nuclear lens opacification grade II or more at baseline had a mean myopic shift of -0.65 D. There was a mean change of 0.13 D in the astigmatism against the rule during the 5 years. The data on axial length are available from the follow-up study only. The mean axial length for those 50 to 59 years of age at baseline was 23.56 mm (standard deviation [SD], 1.08 mm), as compared with 23.23 mm (SD, 1.27 mm) for those 70 years of age and older at baseline (P<0.04).
  
  
  CONCLUSIONS
  We found a hyperopic shift for those younger than 70 years of age at baseline, although eyes with nuclear opacification grade of II or more at baseline were associated with a myopic shift. There was also an age-related shift against the rule for the axis of astigmatism during the 5-year period. Our results may be useful for predicting long-term outcome of refractive surgery.
authors.affiliation: Department of Ophthalmology, University of Iceland, Reykjavik, Iceland.
authors.forename: Elinborg
authors.initials: E
authors.lastname: Gudmundsdottir
authors.forename: Arsaell
authors.initials: A
authors.lastname: Arnarsson
authors.forename: Fridbert
authors.initials: F
authors.lastname: Jonasson
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000453:epidemiology / Q000503:physiopathology; D015331:Cohort Studies; D003315:Cornea / Q000503:physiopathology; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000453:epidemiology* / Q000503:physiopathology; D007055:Iceland / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000453:epidemiology* / Q000503:physiopathology; D012029:Refraction, Ocular; D017678:Sex Distribution