[Correction and induction of high-order aberrations after standard and wavefront-guided LASIK and their influence on the postoperative contrast sensitivity].

Abstract

BACKGROUND:

Wavefront-guided LASIK-treatments should reduce high-order aberrations (HOA). However, both the microkeratome cut as well as the ablation itself induce HOA. The purpose of this study was to investigate the amount of corrected preoperative measured HOA and induction of new HOA.

METHODS:

In this retrospective study 67 eyes of 45 myopic patients (- 2 to - 8.1 D SE; spherical equivalent) were treated by standard and wavefront-guided LASIK (Keracor 217z). Pre- and postoperative measurements of total aberrations and contrast sensitivity were performed. The follow-up time was 5.7 +/- 0.9 months.

RESULTS:

Patients with preoperative increased aberrations of 3rd and 4th order and myopia up to 5 D showed a slightly reduction of wavefront deformation. Cases of higher myopic corrections and lower preoperative spherical aberrations developed an increase of spherical aberrations after LASIK. The changes of other HOA showed no correlation with the amount of corrected myopia. Up to - 5 D patients showed the trend to better postoperative contrast sensitivity under 3 and 85 cd/m (2) after wavefront-guided LASIK than after standard LASIK. A significant advantage of wavefront-guided LASIK can be detected under a spatial frequency of 3 CPD (cycles per degree) and 85 cd/m (2). No advantages of any treatment procedure were shown after higher myopic corrections.

CONCLUSION:

If preoperative aberrations of 3rd and 4th order were increased and the myopia is < 5 D (SE) -- wavefront-guided LASIK can reduce total ocular HOA. Aberrometric findings after wavefront-guided LASIK in patients with lower preoperative HOA and myopia > 5 D (SE) are comparable with the results after standard treatment.

• Authors: T Hammer, M Heynemann, I Naumann, G I Duncker
• Journal: Klinische Monatsblatter fur Augenheilkunde (Klin Monbl Augenheilkd) Vol. 223 Issue 3 Pg. 217-24 (Mar 2006) ISSN: 0023-2165 [Print] Germany
• Vernacular Title: Korrektur und Induktion von Aberrationen höherer Ordnung nach Standard- und wellenfrontgeführter LASIK und deren Auswirkungen auf das postoperative Kontrastsehen.
• PMID: 16552654 (Publication Type: Comparative Study, English Abstract, Journal Article)

Topics

• Contrast Sensitivity (physiology)
• Corneal Topography (methods)
• Follow-Up Studies
• Humans
• Keratomileusis, Laser In Situ (methods)
• Myopia (physiopathology, surgery)
• Postoperative Complications (etiology, physiopathology, therapy)
• Refraction, Ocular (physiology)
• Retrospective Studies
• Treatment Outcome
• Visual Acuity (physiology)