1. Preoperative Distribution of Higher Order Aberrations in Patients Undergoing LASIK
Perry S. Binder, MS MD

2. Financial Disclosure Abbott Medical Optics – A, B, C, E
Allergan, Inc. – A, B, D,E
Acufocus, Inc. – A, D, E
UV X – A, D
Ophthonix, Inc. – A
Outocmes Analysis Software – P
RXVP - P

3. Introduction
It has been suggested that Wavefront-guided treatments be considered only if the magnitude of preoperative root-mean-square (RMS) higher order aberrations is >0.30 microns.
The conclusions were based on the use of Tscherring aberrometry in fewer than 300 eyes

4. Purpose
To determine the incidence and distribution of higher order aberrations (HOA) in patients undergoing LASIK and to compare the HOA root mean square (RMS) in patients who underwent wavefront aberrometry with either the CustomVue Wavescan (AMO) or the Allegretto LadarWave (Alcon) aberrometers.

5. Methods
Retrospective analysis of a clinical database (Outcomes Analysis Software v 4.1, San Diego, CA) of 3,568 consecutive eyes undergoing LASIK performed by a single surgeon.
The CustomVue Wavescan aberrometer was used on 1,365 eyes
The Allergretto LadarWave was used on 2,194 eyes.
All aberrometry was performed by one of several technicians
A previous comparison of these aberrometers on a small number of eyes and plastics showed them to be equivalent (Warden et. al. J Refr. Surg. 24: , 2008)

6. HOA RMS: Eyes with more than 0.3 µm Total on Both Aberrometers
Pre-op
Post-op
Preoperatively, 46.8% of eyes (1,670/3,568) had HOA RMS of 0.3 µm or greater
Irrespective of pupil diameter

7. HOA RMS: Pre-op by Aberrometer
Custom Vue
Ladar Wave
Preoperatively, mean HOA RMS was significantly greater in the LadarWave group
than in the CustomVue WaveScan group.
This difference was statistically significant (P<.001).

8. Significantly Better Preop Defocus and SA with CustomVue WaveScan* ** **
*P=.0299; **P<.001

9. Significantly Better Postop Defocus, Coma and SA with CustomVue WaveScan* * *
*P<.001

10. HOA RMS: Correlation Between Aberrometer and RMSm – No Difference
Pre-op
Post-op

11. Conclusions
Using Hartman Shack aberrometers, many eyes (>40%) have a preoperative HOA RMS > 0.3 um for mesopic pupils >=6.00 mm
Both pre- and post-op, CustomVue Wavescan measured significantly less RMS HOA (P<.001) than the Allegretto LadarWave in myopic eyes, but both had > 45% of eyes with HOA RMS >0.3 um.
Both pre- and post-op, defocus and spherical aberration were less with CustomVue Wavescan than with the Allegretto LadarWave aberrometer, (P<.03 for defocus, P<.001 for SA).