title: Analysis of seasonal changes in residual refraction 1-year after corneal laser refractive surgery: a retrospective study.
abstract: OBJECTIVE
  To analyze the effect of seasonal changes in residual refraction 1-year after corneal refractive surgery using the SCHWIND AMARIS laser system.
  
  
  METHODS
  5740 consecutive treatments have been retrospectively reviewed. For all eyes, aspheric treatments were planned with the Custom Ablation Manager software and the ablations were performed with the SCHWIND AMARIS system (SCHWIND eye-tech-solutions). Seasonal outcomes were evaluated in terms of residual refraction stratified per treatment month, as well as stratified per year season. Student's T test comparing stratified values with global ones was used for the statistical analysis.
  
  
  RESULTS
  Treatments performed in April, June, August, September, and October showed relative undercorrections of the spherical equivalent (SE) (-0.09D), whereas treatments performed in January, February, and March showed relative overcorrections of the SE (+0.13D). Similarly, treatments performed in spring and summer showed relative undercorrections of the SE (-0.04D), whereas treatments performed in winter showed relative overcorrections of the SE (+0.10D).
  
  
  CONCLUSIONS
  Seasonal differences in refractive outcomes were observed among a large scale population. The effect of these environmental variables on refractive outcomes warrants further evaluation.
authors.affiliation: VisionClinics, Utrecht, The Netherlands. Electronic address: luger@visionclinics.nl.
authors.forename: Michiel H A
authors.initials: MH
authors.lastname: Luger
authors.affiliation: SCHWIND eye-tech-solutions, Kleinostheim, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Ewering
authors.affiliation: SCHWIND eye-tech-solutions, Kleinostheim, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Arba-Mosquera
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000503:physiopathology*; D012189:Retrospective Studies; D012621:Seasons; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
keywords: Cambios estacionales; Clinical outcomes; Postoperative; Postoperatorio; Resultados clínicos; Seasonal changes