Comparison of LASEK and LASIK with thin and ultrathin flaps after excimer laser ablation with the SCHWIND Aspheric ablation profile

J Refract Surg. 2011 Jan;27(1):38-48. doi: 10.3928/1081597X-20100406-01. Epub 2010 Apr 15.

Abstract

Purpose: to compare visual, refractive, and wavefront aberration outcomes of laser epithelial keratomileusis (LASEK), thin-flap LASIK (flap thickness 110 to 130 microm), and ultrathin-flap LASIK (flap thickness <110 microm) after excimer laser ablation with an aspheric ablation profile.

Methods: a retrospective analysis of 97 eyes of 56 patients with myopia <6.00 diopters (D) sphere (30 eyes, alcohol-assisted LASEK; 30 eyes, LASIK 110; and 37 eyes, LASIK 130) was conducted. Surgery was performed using the SCHWIND ESIRIS Aberration-Free aspheric ablation profile and the Carriazo-Pendular microkeratome.

Results: groups were comparable preoperatively except for lower astigmatism and ocular trefoil (3,+3) in the LASIK 130 group and lower corneal thickness in the LASEK group. At 6 months postoperative, the groups were comparable for uncorrected and corrected distance visual acuity, efficacy index, safety, and refractive predictability. All groups demonstrated improved contrast sensitivity. All groups demonstrated a significant change in spherical aberration compared to preoperative levels. The induced spherical aberration was 0.057 microm/D in the LASEK group, 0.039 microm/D in the LASIK 110 group, and 0.044 microm/D in the LASIK 130 group. Other higher order aberrations did not show significant change except for a reduction in corneal trefoil (P=.034) in the LASEK group and increased ocular trefoil (P=.002) in the LASIK 110 group. The extent of change in higher order aberrations was not significantly different among groups.

Conclusions: the aspheric ablation profile is safe, effective, and predictable and produces similar visual and refractive results with three different surgical approaches of LASEK, thin-flap LASIK, and ultrathin-flap LASIK. The ablation profile demonstrated a low induction rate of higher order aberrations regardless of surgical approach.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Contrast Sensitivity / physiology
  • Corneal Stroma / pathology*
  • Corneal Topography
  • Corneal Wavefront Aberration / physiopathology
  • Female
  • Humans
  • Keratectomy, Subepithelial, Laser-Assisted / methods*
  • Keratomileusis, Laser In Situ / methods*
  • Lasers, Excimer / therapeutic use*
  • Male
  • Middle Aged
  • Myopia / physiopathology
  • Myopia / surgery*
  • Refraction, Ocular / physiology
  • Retrospective Studies
  • Surgical Flaps / pathology*
  • Visual Acuity / physiology
  • Young Adult