Analysis of higher-order aberrations (HOAs) and related factors after small incision lenticule extraction (SMILE) surgery

Abstract

Objective To investigate the changes in higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) surgery for myopia and myopic astigmatism, and to evaluate the association between the postoperative changes in HOAs and related factors. Methods This was a retrospective study that included 81 patients (162 eyes) who had undergone SMILE for myopia or myopic astigmatism. The follow-up period was 3 months. Ocular HOAs with a 6 mm pupil diameter were measured by a WaveScan aberrometer preoperatively and 3 months postoperatively. The angle kappa and Q value were obtained with an ocular analyzer at same time. Paired t test was used to compare the ocular variables before and after surgery. Spearman rank and Pearson correlation coefficient analysis were used to assess the relationship between changes in total HOA and different HOAs with multiple factors that included pre-SE, astigmatism, angle kappa, etc. Results Statistically significant differences were found in the changes in total HOA (t=-12.24, P 0.05) . The three-month postoperative C40 and △C40 were correlated with pre-SE (r=0.35, 0.29, P 0.05). Conclusion A significant postoperative increase in total HOA after SMILE surgery is correlated with preoperative SE, but is not correlated with the degree of astigmatism. Postoperative C40 was only correlated with preoperative SE, while a postoperative increase in C31 was correlated with the preoperative degree of astigmatism. Key words: Myopia; Small incision lenticule extraction; Aberrations; Astigmatism; kappa angle