title: One year follow-up of contrast sensitivity following conventional laser in situ keratomileusis and laser epithelial keratomileusis.
abstract: OBJECTIVE
  To determine the effect of conventional laser in situ keratomileusis (LASIK) and laser epithelial keratomileusis (LASEK) for myopia on contrast sensitivity (CS) using the Pelli-Robson and Vector Vision CSV-1000E CS tests.
  
  
  METHODS
  A prospective, comparative study was conducted on 36 eyes of 36 patients with myopia undergoing LASIK (18 eyes) and LASEK (18 eyes). Surgery was performed using the Technolas 217z laser (Bausch & Lomb). CS was recorded preoperatively and at 3, 6 and 12 months postoperatively.
  
  
  RESULTS
  No statistically significant difference was found in LogMAR uncorrected visual acuity post-LASIK (-0.02 ± 0.16) and LASEK (-0.04 ± 0.14). Using the Pelli-Robson, CS was significantly lower in the LASIK group 3 and 6 months postoperatively. No significant postoperative reduction in CS was observed in either treatment group. Using the CSV-1000E test, CS was significantly reduced post-LASIK at 3 (p = 0.05) and 6 (p = 0.05) cycles/degree under photopic conditions. No significant postoperative change occurred in the LASEK group under photopic or scotopic conditions. There was no significant difference in postoperative CS between the LASIK and LASEK groups at 3, 6, 12 or 18 cycles/degree using the CSV-1000E test.
  
  
  CONCLUSIONS
  One year postoperatively, there was no difference in CS between both treatment groups using the Pelli-Robson and CSV-1000E tests. CS was reduced postoperatively in the LASIK group at the lower spatial frequencies under photopic conditions. No postoperative change was detected in CS following LASIK or LASEK using the Pelli-Robson test.
authors.affiliation: Mater Private Hospital, Dublin 7, Ireland.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Townley
authors.forename: Caitriona
authors.initials: C
authors.lastname: Kirwan
authors.forename: Michael
authors.initials: M
authors.lastname: O'Keefe
mesh_terms: D057128:Aberrometry; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D003319:Corneal Stroma / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D013524:Surgical Flaps; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult