Pattern of increase in Spherical Aberration and Coma After Femtosecond Laser Assisted In-Situ Keratomileusis Using an Aspheric Ablation Profile

Purpose: To determine the contribution of spherical aberration and coma to the total ocular high order aberration before and after femto laser-assisted in-situ keratomileusis using an aspheric ablation profile. Methods: This is a prospective interventional study that was conducted on 34 eyes of 17 patients in the interval between January 2021 and June 2021. Patients did a preoperative aberrometry and corneal tomography. They underwent FS-LASIK surgery using an aspheric ablation profile. The total ocular aberrometry and corneal tomography were repeated one month postoperatively. Results: The mean preoperative contribution of coma to total ocular HOA was 52.16 % with SD of ± 25.59% which declined to 49.48 % with SD of ± 22.53 % postoperatively. The mean preoperative contribution of SA to total ocular HOA was 38.91 % with SD of ± 15.35 % which increased significantly to 51.25 % with SD of ± 16.55 % postoperatively. Conclusion: Post-operative contribution of corneal spherical aberrations to total ocular HOA showed a statistically significant increase compared to pre-operative. However, there was no significant change in coma contribution.