Abstract
Purpose: :
To compare measurements obtained with four different aberrometers: LADARWave®, Visx WaveScan®, Allegro Wave Analyzer®, Zywave®.
Methods: :
An IRB approved prospective study was performed on 14 healthy eyes. Multiple readings per eye, at a single visit, were obtained with each of the four aberrometers. The wavefront aberration data was analyzed including wavefront refraction, total aberrations, total higher order aberrations (HOA), defocus, astigmatism, coma and spherical aberration (SA). Pearson's correlation coefficient (r) was calculated to compare the four aberrometers for each of the parameters.
Results: :
Spherical equivalents ranged from -4.5 to +0.5 (median = -0,125). Pearson's correlation coefficients ranged from 0.949 to 0.991 for spherical wavefront refraction, from 0.969 to 0.997 for total aberration and from 0.919 to 0.954 for astigmatism (P<0.001 for all parameters), showing the best correlations. Defocus and SA correlation range was 0.868 to 0.997 and 0.783 to 0.97, respectively (P<0.001). The wavefront cylinder refraction for the Visx WaveScan® and Zywave® was not significantly correlated (r = 0.500, P = 0.07). However, for the other aberrometer comparisons, wavefront cylinder refraction was statistically significant but less tightly correlated (r = 0.67, P<0.01 to r = 0.932, P<0.001), similar to total HOA (r = 0.667, P<0.01 to r = 0.924, P<0.001). Coma was not very well correlated with any of the 4 aberrometers (r = 0.729, P<0.01 to r = 0.79, P<0.001).
Conclusions: :
Our preliminary data suggests that wavefront measurements for lower order aberrations are well-correlated, except for cylinder measurements. Less correlation was observed between the measurements of total HOA, spherical aberration and coma. Caution should be used when comparing data between devices for higher order aberrations.
Clinical Trial: :
http://www.clinicaltrials.gov NCT 01230164
Keywords: aberrations • refractive surgery: optical quality • imaging/image analysis: clinical