title: Intraocular lens power calculation after previous myopic laser vision correction based on corneal power measured by Fourier-domain optical coherence tomography.
abstract: OBJECTIVE
  To use Fourier-domain optical coherence tomography (OCT) to measure corneal power and calculate intraocular lens (IOL) power in cataract surgeries after laser vision correction.
  
  
  METHODS
  Doheny Eye Institute, Los Angeles, California, and Cullen Eye Institute, Houston, Texas, USA.
  
  
  METHODS
  Prospective comparative case series.
  
  
  METHODS
  Patients with previous myopic laser vision correction who had monofocal IOL implantation were enrolled. A Fourier-domain OCT system was used to measure corneal power and pachymetry. Axial length and anterior chamber depth were measured with partial coherence biometry. An OCT-based IOL formula was developed, and the mean absolution error (MAE) of postoperative refraction was compared with that for the Haigis-L formula. At Doheny, corneal power was also measured using the clinical history method, the contact lens overrefraction method, and slit-scanning tomography total optical power.
  
  
  RESULTS
  Sixteen eyes of 16 patients were enrolled at the 2 sites. Previous laser vision correction ranged from -9.81 to -0.88 diopter (D). The MAE was 0.50 D for OCT-based IOL calculation and 0.76 D for the Haigis-L formula (P=.14). In the 6 eyes enrolled at Doheny, the MAE of OCT-based IOL calculation was 0.60 D. In comparison, the contact lens overrefraction (MAE = 1.46 D, P<.05) and clinical history (MAE = 1.78 D, P<.05) methods were worse. Slit-scanning tomography gave an MAE of 1.28 D (P>.05).
  
  
  CONCLUSIONS
  The predictive accuracy of OCT-based IOL power calculation was equal to or better than current standards in post-laser vision correction eyes.
authors.affiliation: Center for Ophthalmic Optics and Lasers, Doheny Eye Institute, University of Southern California, Los Angeles, California, USA.
authors.forename: Maolong
authors.initials: M
authors.lastname: Tang
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Koch
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: David
authors.initials: D
authors.lastname: Huang
mesh_terms: D000368:Aged; D001699:Biometry; D003315:Cornea / Q000503:physiopathology; D005260:Female; D005583:Fourier Analysis; 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 / Q000503:physiopathology / Q000601:surgery*; D055095:Optics and Photonics; D018918:Phacoemulsification; D011446:Prospective Studies; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence