title: Role of preoperative cycloplegic refraction in LASIK treatment of hyperopia.
abstract: BACKGROUND
  Previous studies have suggested that, to improve refractive predictability in hyperopic LASIK treatments, preoperative cycloplegic or manifest refraction, or a combination of both, could be used in the laser nomogram. We set out to investigate (1) the prevalence of a high difference between manifest and cycloplegic spherical equivalent in hyperopic eyes preoperatively, and (2) the related predictability of postoperative keratometry.
  
  
  METHODS
  Retrospective cross-sectional data analysis of consecutive treated 186 eyes from 186 consecutive hyperopic patients (mean age 42 [±12] years) were analyzed. Excimer ablation for all eyes was performed using a mechanical microkeratome (SBK, Moria, France) and an Allegretto excimer laser platform. Two groups were defined according to the difference between manifest and cycloplegic spherical equivalent which was defined as ≥1.00 diopter (D); the data was analyzed according to refractive outcome in terms of refractive predictability, efficacy, and safety.
  
  
  RESULTS
  In 24 eyes (13 %), a preoperative difference of ≥1.00D between manifest spherical equivalent and cycloplegic spherical equivalent (= MCD) occurred. With increasing preoperative MCD, the postoperative achieved spherical equivalent showed hyperopic regression after 3 months. There was no statistically significant effect of age (accommodation) or optical zone size on the achieved spherical equivalent.
  
  
  CONCLUSIONS
  A difference of ≥1.00D occurs in about 13 % of hyperopia cases. We suggest that hyperopic correction should be based on the manifest spherical equivalent in eyes with preoperative MCD <1.00D. If the preoperative MCD is ≥1.00D, treatment may produce manifest undercorrection, and therefore we advise that the patient should be warrned about lower predictability, and suggest basing conclusions on the arithmetic mean calculated from the preoperative manifest and cycloplegic spheres.
authors.affiliation: Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany. andi.frings@gmail.com.
authors.forename: Andreas
authors.initials: A
authors.lastname: Frings
authors.affiliation: Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Steinberg
authors.affiliation: Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Vasyl
authors.initials: V
authors.lastname: Druchkiv
authors.affiliation: Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Linke
authors.affiliation: Department of Ophthalmology, University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Toam
authors.initials: T
authors.lastname: Katz
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000601:surgery*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006956:Hyperopia / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000494:pharmacology*; D011300:Preoperative Care / Q000379:methods*; D012029:Refraction, Ocular / Q000187:drug effects*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D009184:Mydriatics
keywords: Cycloplegic refraction; Hyperopia; LASIK; Manifest refraction; Refractive predictability