Corneal aberrations after small-incision lenticule extraction versus Q-value-guided laser-assisted in situ keratomileusis

Aim: To compare the changes in anterior corneal surface aberration characteristics after small-incision lenticule extraction (SMILE) versus Q-value-guided femtosecond laser-assisted in situ keratomileusis (Q-FS-LASIK) Methods: In this prospective comparative study, 102 patients with myopia and myopic astigmatism were divided between the SMILE and Q-FS-LASIK groups, consisting of 51 patients each. High order aberration (HOA), primary spherical aberration (PSA), and primary coma aberration (PCA) of the central 6 mm region of the anterior corneal surface were quantitatively assessed using pre-and post-operative Sirius scanning, and then statistical analysis with repeated measures analysis of variance. Results: Both types of surgery were associated with statistically significant increases in post-operative HOA, PSA, and PCA (both groups P <0.01). In the SMILE group, the variations in HOA, PSA, and PCA were not statistically significant starting at post-operative week 2 (P >0.05). In the Q-FS-LASIK group, the variations in HOA and PCA were not statistically significant starting at post-operative day 1 (P >0.05). Conclusion: Both SMILE and Q-FS-LASIK resulted in an increase in HOA, PSA, and PCA at post-operative day 1. However, Q-FS-LASIK introduced lower HOA and showed better stability. Spherical measurement is highly related to PSA.