1. Wavefront Correction of high refractive errors
with aspheric-shotfiles to increase depth-of-field with ASA-Lasek: 3year-follow-up.
3 year-follow-up
Preliminary Results of a Multicenter Study
S. Lee 1, Dan Z. Reinstein 2 , E. Schroeder 1, M. Kim 1 , H. Lee 1, SD. Lee 1 ,
1 ASA-Vision Clinics Seoul
2 London Vision Clinic, England
The Authors have no financial interest in the subject matter of this poster 1

2. Study Design:
Prospective multi-center clinical trial (between 01/2006 and 12/2009)
Total of 258 eyes of consecutive 129 patients: Age (mean): ± 5.93 years
Dominant Eye: n = 129 (eyes) treated with Standard Ablation Profiles (SAP)
Non-Dominant Eye: n = 129 (eyes) treated with Individual New Aspheric Customized
Ablation Profiles (NAP); by adding a shotfile with a negative spherical aberration Z4(0) to
shift the spherical aberration into the plus range
All eyes treated with the MEL-80 (Carl Zeiss Meditec, Jena, Germany)
Mean Spherical Equivalent:
Myopia: D ± 2.36 D ( range -8.00D to D;
Astigmatism: -0.50D to -6.50D;
Hyperopia: +2.69D to +2.52D ( range +3.00D to +6.00D;
Astigmatism: -0.50D to D);
It was a prospective Cohort Study between 2007 and We included 32 eyes of 16 patients with a dropout rate of 0%.
The dominant eye was treated with Standard Ablation Profiles whereas the non-dominant eye was treated with an additional negative spherical aberration Z4(0).
All eyes treated with the Spotscanning Laser MEL80
Mean Spherical Aequivalent for Myopia was D, for Hyperopia +2.79D and Astigmatism up to D.

3. ASA + Z(4,0) ▬ Addition of negative spherical aberration ▬
Advanced Surface Ablation (ASA80 ® / ASA-Lasek ® ) in all cases
MEL80 Ablation Profiles:
TSA – (Tissue Saving Ablation) Type Munnerlyn-profile with k-value compensation
ASA – (Aberration Smart Ablation) Type TSA plus aspheric component = SAP: Standard Ablation Profiles
NAP: New-individual-Aspheric-ablation-Profiles
ASA + Z(4,0) ▬ Addition of negative spherical aberration ▬
Statistical Analyses SPSS v.15.0
All tests used were nonparametric, based on Kolmogorov- Smirnov-Test:
no parametric t-test for significance; instead: Wilcoxon, Mann-Whitney-U,
Kruskal-Wallis-Test.(p< 0.05)
Advanced Surface Ablation ASA-Lasekwas used in all cases
Just to remind you, the MEL80 basically has 2 ablation profiles:
1) the TSA (Type Munnerlyn Profile with k-value compensation) and
2) the Aberration Smart Ablation Profile ( Type TSA plus an aspheric component).
Our new individual aspheric ablation profile basically is a mixture of both standard profiles with an addition of negative spherical aberration Z4(0).
Statistical analyses was performed with SPSS.

4. Clinical Results
Having a look at the Best Corrected Visual Acuity in myopic patients, we can see, that the results are significantly better with the Non-dominant eye using an additional Z4(0) ablation shotfile, also safety with 97% is better than using the standard ablation profiles on the dominant eye with 88%. 4

5. Having a look at the Best Corrected Visual Acuity in myopic patients, we can see, that the results are significantly better with the Non-dominant eye using an additional Z4(0) ablation shotfile, also safety with 97% is better than using the standard ablation profiles on the dominant eye with 88%. 5

6. Efficacy and Predictability postop 3 years
Analyzing efficacy and predictability, we found significant improvements of the clinical parameters in the Nondominant eye in myopic as well as hyperopic patients, using again a additional Z4(0) shotprofile. 6

7. Contrast Sensitivity was significantly better in the Nondominant Eyes after 12 months, whereas in the Dominant eye it was unchanged. 7

8. We found the same behavior with Mesopic Contrast Sensitivity after 2 years.8

9. Interestingly Glare Vision in both groups postop was worse than preop
Interestingly Glare Vision in both groups postop was worse than preop. Even after 2 years the preop value could not be reached again.
This decrease was significantly with a p-value of smaller point 05 (<.05) 9

10. Regarding postop pain, Re-ep time and reticular Haze formation there were no differences. Although, with the use of MMC (0.02%) in the Nondominat Eye, we could find less Haze after 6 months, whereas after 2 years the results were similar. 10

11. The most decisive difference is the increase of Depth of Field in the Non-dominant eye, due to the additional Z4(0) shotprofile. 11

12. Summary Conclusion Advanced Surface Ablation (ASA80®/ASA-Lasek®)
Postoperative Foreign Body Sensation, Fast Re-epithelialization time, Fast Recovery of BCVA, No significant Reticular Haze Formation after 1 year, Haze onset is less likely with the use of MMC in the first 6 months
Addition of negative spherical aberration Z(4,0)
Significant clinical advantages over standard ablation profiles in the 6 and 12
months results
Increased depth of field and an improved quality of vision
Less tissue is needed compared to Standard Ablation Profiles
Contrast Sensitivity under daylight and mesopic conditions postop significantly better (p<.05)
Glare Vision unchanged
Conclusion
Altering Zernike Polynomials seems to be a successful approach for the treatment of high refractive errors.
To sum it up, by adding a negative spherical aberration in the Non-dominant eye we did find significant advantages over standard ablation profiles, especially regarding depth of field and quality of vision, like for instance Contrast Sensitivity and Mesopic Contrast Sensitivity. Thus Glare Vision was unchanged.
As a conclusion we can postulate, that altering Zernike Polynomials is a promising new approach for the correction of higher refractive errors.
Thank you very much for you kind attention.