title: Comparison of Intraoperative Aberrometry, OCT-Based IOL Formula, Haigis-L, and Masket Formulae for IOL Power Calculation after Laser Vision Correction.
abstract: OBJECTIVE
  To compare the accuracy of intraoperative aberrometry technology and the Fourier-domain optical coherence tomography (OCT)-based intraocular lens (IOL) formula for IOL power calculation in eyes undergoing cataract surgery after previous laser vision correction (LVC) compared with established methods.
  
  
  METHODS
  Retrospective consecutive case series.
  
  
  METHODS
  Patients undergoing cataract surgery with a history of LASIK or photorefractive keratectomy.
  
  
  METHODS
  The IOL power was estimated preoperatively using the IOLMaster 500 (Carl Zeiss Meditec, Dublin, CA) to calculate the Haigis-L and Masket regression formulae (when prior data were available), and the Optovue RTVue (Optovue Inc, Fremont, CA) spectral domain OCT was used to obtain the Fourier-domain OCT-based IOL formula. The Optiwave Refractive Analysis (ORA) System (WaveTec Vision Systems Inc, Aliso Viejo, CA) wavefront aberrometer measured aphakic refractive measurements intraoperatively and calculated the IOL power with a modified vergence formula. Comparative analysis was done for predictive accuracy of IOL power determination using 2 conventional methods and 2 new technologies: the Haigis-L formula, Masket regression formula, ORA intraoperative aberrometry, and Optovue RTVue Fourier-domain OCT-based IOL formula. Patients without historical data (N = 39) were compared using 3 methods (Haigis-L, ORA, and Optovue), and patients with historical data (N = 20) were compared using all methods (Masket regression formula, Haigis-L, ORA, and Optovue).
  
  
  METHODS
  Median absolute error (MedAE), mean absolute error (MAE), and percentage of eyes within ±0.25, ±0.50, ±0.75, and ±1.00 diopters (D) of refractive prediction error.
  
  
  RESULTS
  A total of 39 eyes of 29 patients without historical data were analyzed separately from 20 eyes of 20 patients with historical data. In the group without historical data (N = 39), 49% of eyes were within ±0.25 D, 69% to 74% of eyes were within ±0.50 D, 87% to 97% of eyes were within ±0.75 D, and 92% to 97% of eyes were within ±1.00 D of targeted refractive IOL power prediction error. The MedAE was 0.26 D for Haigis-L, 0.29 D for ORA, and 0.28 D for Optovue. The MAE was 0.37 D for Haigis-L, 0.34 D for ORA, and 0.39 D for Optovue. In the group with historical data (N = 20), 35% to 70% of eyes were within ±0.25 D, 60% to 85% of eyes were within ±0.50 D, 80% to 95% of eyes were within ±0.75 D, and 90% to 95% of eyes were within ±1.00 D of targeted refractive IOL power prediction error. The MedAE was 0.21 D for the Masket regression formula, 0.22 D for the Haigis-L formula, 0.25 D for ORA, and 0.39 for Optovue. The MAE was 0.28 D for the Masket regression formula, 0.31 D for the Haigis-L formula, 0.37 D for ORA, and 0.44 D for Optovue. There was no statistically significant difference among the methods.
  
  
  CONCLUSIONS
  Newer technology to estimate IOL power calculations in eyes after LVC shows promising results when compared with established methods.
authors.affiliation: The David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California; Advanced Vision Care, Los Angeles, California. Electronic address: nicfram@yahoo.com.
authors.forename: Nicole R
authors.initials: NR
authors.lastname: Fram
authors.affiliation: The David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California; Advanced Vision Care, Los Angeles, California.
authors.forename: Samuel
authors.initials: S
authors.lastname: Masket
authors.affiliation: Baylor College of Medicine, Houston, Texas.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
mesh_terms: D057128:Aberrometry; D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry / Q000379:methods*; D048988:Corneal Surgery, Laser; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D006956:Hyperopia / Q000601:surgery; D007432:Intraoperative Period; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery; D055095:Optics and Photonics; D018918:Phacoemulsification; D019591:Pseudophakia / Q000503:physiopathology; D012029:Refraction, Ocular / Q000502:physiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology