Comparison of Higher-order Aberrations (HOAs) between Wavefront-guided Laser in Situ Keratomileusis and Laser Epithelial Keratomileusis

ABSTRACT

PURPOSE: To compare the change in higher-order aberrations (HOAs) in the treatment of myopia between two different Wavefront-guided excimer ablations laser in situ keratomileusis (LASIK) and laser assisted subepithelial keratomileusis (LASEK). METHODS: One hundred and four eyes of 52 patients were treated with wavefront-guided LASIK while 104 eyes of 54 patients were treated with wavefront-guided LASEK. Pupil size, best-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), manifest refraction, corneal topography, pachymetry, and wavefront aberrations were examined preoperatively. BCVA, UCVA, manifest refraction, and wavefront aberrations were measured at 1 and 3 months postoperatively. The Hartmann-Shack aberrometer (WaveScan, VISX) was used to measure the overall wavefront aberrations for scotopic pupils. RESULTS: The wavefront error of HOAs did not increase postoperatively in either group compared with preoperative values. Normalized polar Zernike coefficients compared between preoperative and postoperative values showed a statistically significant increase in spherical aberration term in the wavefront-guided LASIK group (p<0.001). Comparing normalized polar Zernike coefficients values between the two groups, the spherical and 2nd coma aberrations at postoperative 1 month in wavefront-guided LASEK were significantly higher than those of the wavefront-guided LASIK group (p=0.002, both). CONCLUSIONS: HOAs did not increase in either wavefront-guided LASIK or wavefront-guided LASEK compared to the previous conventional methods. However, the average RMS wavefront error of the HOAs was lower in the wavefront-guided LASIK group at 1 month postoperatively (p=0.0004).