title: Post-cycloplegia myopic shift in an older population.
abstract: OBJECTIVE
  To demonstrate that use of a mydriatic agent remains a significant confounder in autorefraction of the presbyopic population.
  
  
  METHODS
  The pre- and post-cycloplegic autorefraction results of 37 subjects over 50 years of age were measured using a Humphrey-598 autorefractor. The results of both eyes were included in a multivariate regression analysis.
  
  
  RESULTS
  The average age of the patient sample was 63.4 years. The mean spherical equivalent (SEQ) shifts for the hyperopic, myopic, pseudophakic, and emmetropic eyes were -0.53 D (95% CI -0.77 D to -0.39 D; p < 0.001), -0.38 D (95%CI -0.81 D to +0.04 D; p = 0.077), -0.49 D (95% CI -0.78 D to -0.20 D; p = 0.001), and -0.35 D (95% CI -0.59 D to -0.11 D; p = 0.004), respectively.
  
  
  CONCLUSIONS
  Cyclopleged autorefraction in the presbyopic population is associated with a myopic shift that can potentially lead to overestimation of myopic prevalence. This is an important factor in comparing population studies where cyclogleged autorefraction is used in contrast to non-cyclopleged autorefraction and subjective refraction.
authors.affiliation: The Eye Hospital, Launceston, Australia.
authors.forename: Tze'Yo
authors.initials: T
authors.lastname: Toh
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Kearns
authors.forename: Lindsey W
authors.initials: LW
authors.lastname: Scotter
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
mesh_terms: D000065:Accommodation, Ocular / Q000187:drug effects; D000368:Aged; D000369:Aged, 80 and over; D002924:Ciliary Body / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage*; D009216:Myopia / Q000503:physiopathology*; D011305:Presbyopia / Q000150:complications; D012029:Refraction, Ocular / Q000187:drug effects; D014331:Tropicamide / Q000008:administration & dosage*
chemical_list: D009184:Mydriatics; D014331:Tropicamide