Abstract
Abstract: :
Purpose: To compare the change of higher order (3rd – 5th order) ocular aberrations after implantation of an iris–claw pIOL (Ophtec ArtisanTM) through a scleral tunnel incision and after wavefront–guided laser in situ keratomileusis (wgLASIK, Bausch & Lomb ZyoptixTM). Methods: 18 eyes of 9 patients with implantation of an iris claw pIOL and 18 eyes of 13 patients with wavefront–guided LASIK were examined preoperatively and 1 month postoperatively. The mean pre–operative spherical equivalent (SE) was –9.42±1.42 D in the pIOL group and –8.24±0.75 D in the wgLASIK group. The diameter of the IOL optic was 6 mm, the mean optical zone for wgLASIK treatment was 6.22±0.32 mm. Wavefront measurements were performed with a HARTMANN–SHACK sensor (Zywave, Bausch & Lomb) in mydriasis. The root mean square (RMS) wavefront error was computed for all aberrations of 3rd to 5th order for pupil diameters of 6 mm. Results: On average, total higher–order RMS changed after wgLASIK by 0.306±0.187 µm (factor 1.97) and after pIOL implantation by 0.406±0.333 µm (factor 2.23). 3rd order aberrations increased after wgLASIK by 0.085±0.098 µm (factor 1.70) and after pIOL implantation by 0.311±0.281 µm (factor 2.29). The mean induction of vertical coma (Z 3,–1) was higher in the pIOL group (–0.283 µm vs. –0.159 µm), but reached no statistical significance (p=0.46). Vertical trefoil (Z 3,–3) increased much higher after pIOL implantation (0.550±0.378 µm) than after wgLASIK (0.071±0.176 µm; p<0.001). The mean change of 4th order aberrations was 0.370±0.089 µm (factor 3.49) after wgLASIK and 0.372±0.229 µm (factor 3.71) after pIOL. The increase of primary spherical aberration (Z 4,0) was higher following wgLASIK (0.425±0.139 µm, factor 8.68) than after pIOL implantation (0.391±0.244 µm, factor 5.84; p=0.09). 5th order aberrations showed a small increase both in the wgLASIK group (0.010±0.039 µm, factor 1.44) and in the pIOL group (0.039±0.050 µm, factor 1.65). Conclusions: Both after wgLASIK and pIOL implantation higher order aberrations increased in a similar manner. In the LASIK group Z 4,0 is the dominant aberration, whereas in the pIOL group Z 3,–3 and Z 4,0 contribute to the main increase of HOA.
Keywords: refractive surgery: optical quality • refractive surgery: comparative studies • refractive surgery: phakic IOL