title: New frontiers for the perioperative data method for IOL calculation following corneal refractive surgeries.
abstract: OBJECTIVE
  To evaluate the efficiency of the perioperative data method for intraocular lens (IOL) calculation after correction of myopia and hyperopia with different techniques, including reoperated cases.
  
  
  METHODS
  Thirty-five eyes (26 patients) that developed cataract after corneal refractive procedures were evaluated retrospectively. They were categorized according to initial error of refraction into myopes and hyperopes and according to types of refractive procedures into ablative, incisional, both, or others. Reoperated cases were also considered. Number of refractive procedures was noted. Time interval between the first procedure and cataract extraction was indicated. Perioperative method was used to calculate the K value. SRK/T formula was used to calculate IOL power. Difference between intended and finally achieved manifest refraction was an indicator for efficiency of the calculation.
  
  
  RESULTS
  Postoperatively, 77.2% of cases had manifest refraction +/-1.5 D of intended refraction. There was no difference between myopes and hyperopes in terms of final manifest refraction, best-corrected visual acuity, and difference between intended and finally achieved manifest refraction. Similarly were groups of different types of surgeries. Efficiency of the method decreased with high axial lengths and low IOL powers. Neither the number of refractive surgeries nor time interval between surgeries affected efficiency of the method.
  
  
  CONCLUSIONS
  The perioperative data method is equally effective for myopes and hyperopes. The types, numbers of refractive procedures, as well as the time interval between refractive surgery and cataract extraction do not alter the credibility of the method. In high degrees of myopia, the method gives less accurate results.
authors.affiliation: VISSUM Instituto Oftalmológico de Alicante and Miguel Hernandez University, Alicante, Spain.
authors.forename: I M
authors.initials: IM
authors.lastname: Hamdi
authors.forename: A
authors.initials: A
authors.lastname: Artola
authors.forename: J L
authors.initials: JL
authors.lastname: Alió
mesh_terms: D000328:Adult; D000368:Aged; D002386:Cataract / Q000209:etiology; D002387:Cataract Extraction / Q000379:methods*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ; D007646:Keratotomy, Radial; D054018:Lasers, Excimer; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D055095:Optics and Photonics; D019990:Perioperative Care / Q000379:methods; D018903:Photorefractive Keratectomy; D012029:Refraction, Ocular / Q000502:physiology; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology