title: Improved safety in contemporary LASIK.
abstract: OBJECTIVE
  To examine the risk of serious visual loss in contemporary LASIK.
  
  
  METHODS
  Retrospective, noncomparative, consecutive case series combined with a structured literature review and comparison with historical controls.
  
  
  METHODS
  One thousand consecutive cases of LASIK performed from January 2000 to January 2004 by 1 surgeon. One thousand nine hundred eighty-two cases with 6-month review data in postmillennial Food and Drug Administration (FDA) trials of LASIK for myopia and astigmatism and 5203 patients with 6 month review data in similar premillennial FDA trials.
  
  
  METHODS
  LASIK was performed with the Hansatome microkeratome and a VISX Star (S2, S3, or S4) laser. There were 899 myopic treatments (spherical equivalent < or =-10.5 diopters [D]; average -4.2 D; standard deviations [SD] D = 1.9 D; astigmatism < or =4.75 D), 87 hyperopic treatments (spherical equivalent < or =+4.25 D; average +2.4 D; SD = 0.9 D; astigmatism < or =3.5 D), and 14 treatments for mixed astigmatism (< or =4.5 D). Outcome data were obtained from a review of case notes and compared with historical data from FDA trials.
  
  
  METHODS
  Best-spectacle corrected visual acuity (BSCVA) preoperatively and at final review was compared in our case series with reference to the United Kingdom driving standard (BSCVA> or =20/30). Subsidiary outcome measures included duration of follow-up, intraoperative, and postoperative complication rates. Six-month postoperative data on standard safety criteria (numbers of patients losing > or =2 lines BSCVA, BSCVA <20/40, and final BSCVA <20/25 for patients with preoperative BSCVA > or =20/20) were examined in FDA trials.
  
  
  RESULTS
  In our clinical series, no case with a preoperative BSCVA of 20/20 or better had a final BSCVA of <20/30 at final review (97.5% confidence interval [CI], 0%-0.37%); 4 eyes had a BSCVA <20/25 (0.41%; 95%CI, 0.11%-1.02%). The median interval between surgery and final review was 2 months (range, 1-45 months). In FDA studies recruiting pre-2000, 1.4% of patients lost > or =2 lines of BSCVA versus 0.6% in postmillennial studies (P = 0.005); 0.45% of patients in premillennial studies lost BSCVA to <20/40 compared with no patients in postmillennial studies (P = 0.001); and 1.68% of patients in premillennial studies with a preoperative BSCVA > or =20/20 had a postoperative BSCVA <20/25 compared with 0.16% in postmillennial studies (P< or =0.001).
  
  
  CONCLUSIONS
  Compared with premillennial results, the risk of visual loss is significantly reduced in contemporary LASIK.
authors.affiliation: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. z3078688@student.unsw.edu.au
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Watson
authors.forename: Catey
authors.initials: C
authors.lastname: Bunce
authors.forename: Bruce D S
authors.initials: BD
authors.lastname: Allan
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D012449:Safety; D016896:Treatment Outcome; D014786:Vision Disorders / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology