title: Modified double-K method for intraocular lens power calculation after excimer laser corneal refractive surgery.
abstract: OBJECTIVE
  To propose the new anterior-posterior method (A-P method) that does not require historical data to calculate intraocular lens (IOL) power after laser in situ keratomileusis (LASIK) and to compare the accuracy of the method with other IOL formulas after LASIK.
  
  
  METHODS
  Keio University Hospital, Tokyo, Japan.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Eyes having phacoemulsification and IOL implantation after myopic LASIK were analyzed retrospectively. The A-P method is a modification of the double-K method using the SRK/T formula in which the estimated pre-LASIK keratometry (K) power calculated from the post-LASIK posterior sagittal power in the 6.0 mm zone is used for the preoperative K value in the double-K method and the post-LASIK anterior sagittal power is used for the postoperative K value. The accuracy of the A-P method was compared with that of other formulas that do not require preoperative data and with formulas that require preoperative data.
  
  
  RESULTS
  The median values of the arithmetic and absolute prediction errors using the A-P method were 0.16 diopter (D) and 0.54 D, respectively. The prediction errors using the A-P method were within ± 0.50 D in 46.4% of eyes and within ± 1.00 D in 75.0%. The percentage of eyes within ± 1.00 D of the prediction errors with the A-P method was highest with the no-history methods.
  
  
  CONCLUSIONS
  The A-P method may be a good option for calculating IOL power in eyes having cataract surgery after LASIK when preoperative LASIK data are unavailable.
authors: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
authors: Megumi
authors: M
authors: Saiki
authors: Kazuno
authors: K
authors: Negishi
authors: Naoko
authors: N
authors: Kato
authors: Rika
authors: R
authors: Ogino
authors: Hiroyuki
authors: H
authors: Arai
authors: Ikuko
authors: I
authors: Toda
authors: Murat
authors: M
authors: Dogru
authors: Kazuo
authors: K
authors: Tsubota
mesh_terms: D000328:Adult; D000368:Aged; D058452:Axial Length, Eye; D001699:Biometry / Q000379:methods*; D063171:Corneal Pachymetry; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D055095:Optics and Photonics; D018918:Phacoemulsification / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies