Abstract
Purpose: :
To compare the efficacy, stability, predictability, and safety of Zernike versus (vs) Fourier based treatment tables for myopic patients undergoing CustomVue Wavefront LASIK using VISX S4 with primary keratectomy flaps created by Intralase or Hansatome microkeratome.
Methods: :
Retrospective analysis of 32 eyes of 16 patients with myopia or myopic astigmatism who underwent CustomVue LASIK using the Zernicke vs Fourier treatment tables using Intralase or Hansatome and VISX was conducted. Mean spherical equivalent (SE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), and higher wavefront analyses were determined pre–operatively and at 1 year post–operatively.
Results: :
Mean preoperative SE for Zernicke vs Fourier based treatment eyes was
–4.20 ± 1.78 D (range –6.25 to –1.00 D) vs –3.58 ± 1.4 D (range –6.13 to –1.75D). Mean 1–year post–operative SE for Zernicke vs Fourier based treatment was –0.27 ± 0.41 D (range –1.25 to +0.50) vs –0.22 ± 0.29 (range –0.63 to +0.25). At 1–year postoperatively, 27 of 32 eyes were available for analysis. At 1–year postoperatively, 36%, 72%, and 92% (Zernicke based treatment) vs 46%, 77%, and 100% (Fourier based treatment) of eyes had 20/10, 20/12.5, and 20/20 or better vision. 79% vs 92% of eyes were within 0.5 D of emmetropia at one year postoperatively in the Zernicke vs Fourier treatment groups. All eyes in the Zernicke treatment group either had no change or gained at least 1 Snellen line (BSCVA) whereas 93% of eyes either gained or had no change in Snellen line (BSCVA). Mean higher order aberration values for Zernicke vs Fourier based treatment were Total root mean square (0.91 vs 0.99, p=0.91), defocus (0.71 vs 0.74, p=0.98), astigmatism (0.15 vs 0.31, p=0.04), coma (0.21 vs 0.20, p=0.78), trefoil (0.11 vs 0.11, p=0.80), and spherical aberration (0.17 vs 0.3, p=0.06).
Conclusions: :
Our retrospective analysis of Zernicke vs Fourier based treatment table used for myopic patients undergoing CustomVue LASIK showed that patients in the Fourier group had better 1–year postoperative SE, better efficacy, and better predictability. However, the Fourier group showed a trend toward higher order aberration.
Keywords: refractive surgery: LASIK • refractive surgery • myopia