Comparison of higher order aberrations after LASIK and LASEK for myopia.

PURPOSE: To compare the change in higher order aberrations (HOAs) after LASIK and laser epithelial keratomileusis (LASEK).

METHODS: This prospective comparative study measured HOAs preoperatively and 3 months postoperatively in 65 eyes (41 patients) that underwent LASIK and 65 eyes (50 patients) that underwent LASEK. Preoperative refraction was limited to myopia up to -5.00 diopters (D) and astigmatism
RESULTS: Statistically significant (P<.05) changes in five Zernike polynomial terms following LASIK ( Z4-4, Z40, Z44, Z5-3, Z60) were noted. There was a decrease in Zernike term Z5-3 and increases in the remaining four Zernike terms. Statistically significant changes in five Zernike polynomial terms following LASEK ( Z3-1, Z40, Z5-5, Z5-1, Z60) were noted. There was a decrease in Zernike term Z3-1 and increases in the remaining four Zernike terms.

CONCLUSIONS: Wavefront-guided LASIK and LASEK caused increases in spherical aberration, with LASIK additionally causing increases in two fourth order HOAs and LASEK additionally causing increases to two fifth order HOAs. As the same laser treatment was applied, it is presumed that the differences relate to the method of flap creation.