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104. Jahrestagung der Deutschen Ophthalmologischen Gesellschaft 2006
Abstract
Abstract
FR.06.04 Comparison of pre and postoperative contrast sensitivity and wavefront deformation of standard and wavefront guided LASIK Hammer T., Heynemann M., Duncker G. I. W.
Department of Ophthalmology, University Halle-Wittenberg Objective: The theoretical aim of wavefront guided (WF) LASIK is to reduce the preoperatively existing high order aberrations and therefore an increase of contrast sensitivity postoperatively. Earlier results showed that refractive surgery induces high order aberrations. We wanted to show, whether WF-LASIK has a postoperative advantage in contrast sensitivity and high order aberrations compared to the classical sphero-cylindrical ablation.
Methods: 116 myopic eyes of 63 patients (-2 D to -10 D (SE)) were treated in a single blind study, with either standard-(S) or WF-LASIK. We used the Technolas 217z Laser. For S-LASIK PlanoScanTM and for WF-LASIK the ZyoptixTM-mode was used. Pre- and postoperatively high order aberration, contrast sensitivity and mesopic visual acuity (FACT-Chart Ginsburg-Box, logMAR contrast, Meso-Test II) were measured.
Results: After S-LASIK (low and high myopia) the RMS increased. Using ZyoptixTM up to -5 D myopia avoided the increase of high order aberration in the treated eye. However, that effect disappeared in the range of -5 to -10 D. For S-LASIK there was an individual increase of coma independent of the amount of preoperative myopia. Specifically for the WF-LASIK up to -5 D an increase of spherical aberration could be prevented. The Ginsburg-Box showed a decrease of contrast sensitivity in low and medium myopic area at 6, 12 and 18 cycles per degree (cdp) and 85 cd illumination. After WF-LASIK the postoperative refraction was stable and at 1,5 cpd and 85 cd there was an increase of contrast sensitivity. Using logMar charts there was the tendency of increased contrast sensitivity for WF-LASIK and decrease of contrast sensitivity for S-LASIK. The Meso-Test showed no change in low and medium myopia, however, in high myopic eyes a decrease in both treatments.
Conclusions: Using WF-LASIK up to -5 D is able to keep the preoperative contrast sensitivity and to prevent the postoperative increase of high order aberration. After myopic correction over -5 to -10 D there is an increase of RMS and a decrease of contrast sensitivity. After S-LASIK there is an increase of RMS and decrease of contrast sensitivity, independent of the treatment range.
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