title: Meta-analysis of sex differences in presbyopia.
abstract: OBJECTIVE
  Uncorrected presbyopia is a significant cause of visual disability globally. Greater comprehension of the etiology of presbyopia and its contributing factors among medical and vision care providers could lead to changes in correction methods and account for sex differences in near-vision requirements.
  
  
  METHODS
  A meta-analysis was performed using nine cross-sectional studies that provided sufficient data to compare the prevalence and magnitude of presbyopia among men and women. This analysis was further subdivided into measurement methods to determine what differences in presbyopia might exist between men and women.
  
  
  RESULTS
  Studies of presbyopia including sex as a contributing factor were highly heterogenic (P = 0.01) but overall found female sex to be statistically significant in predicting earlier onset for presbyopia with an adjusted confidence interval (CI) using the Shore method of 95% CI [1.02, 1.45]. When limited to studies only measuring accommodative amplitude, female sex was not associated with presbyopia in a fixed effects model with a 95% CI [0.49, 1.07].
  
  
  CONCLUSIONS
  While an association between female sex and presbyopia for subjective measurements (near spectacle prescriptions and add powers) was indicated, measurements of accommodative amplitude show a weak tendency toward the opposite.
  
  
  CONCLUSIONS
  This suggests that increased association of presbyopia for women is not due to a physiologic difference in accommodation but rather due to other sex differences, such as tasks performed and viewing distances. Age-based correction nomograms for presbyopia should therefore consider these sex differences when prescribing add powers for near tasks.
authors.affiliation: Bioengineering Department, School of Optometry, University of California-Berkeley, CA 94720-2020, USA. dradamh@berkeley.edu
authors.forename: Adam
authors.initials: A
authors.lastname: Hickenbotham
authors.forename: Austin
authors.initials: A
authors.lastname: Roorda
authors.forename: Craig
authors.initials: C
authors.lastname: Steinmaus
authors.forename: Adrian
authors.initials: A
authors.lastname: Glasser
mesh_terms: D005260:Female; D014943:Global Health; D006801:Humans; D008297:Male; D011305:Presbyopia / Q000453:epidemiology*; D015995:Prevalence; D017678:Sex Distribution; D012737:Sex Factors