Optical and visual quality after small-incision lenticule extraction

Purpose To examine the relationship between corneal higher-order aberrations (HOAs), scatter, and residual refraction with visual symptoms and visual acuity after small-incision lenticule extraction (SMILE) for myopia and astigmatism. Setting University Eye Clinic, Aarhus, Denmark. Design Prospective case series. Methods Eyes had small-incision lenticule extraction for myopia or myopic astigmatism. Examinations were performed preoperatively and 1 day, 7 days, 1 month, and 3 months postoperatively and included subjective refraction, Pentacam HR measurements, scatter measurements (objective scatter index [OSI]), and questionnaires on visual quality and symptoms. Results The mean preoperative spherical equivalent (SE) was −7.08 diopters (D) ± 1.17 (SD). At 3 months, the mean uncorrected distance visual acuity (UDVA) was −0.03 ± 0.11 logarithm of the minimum angle of resolution and the mean SE, −0.17 ± 0.33 D; the OSI increased by a mean of 0.22 ± 0.53 (P = .06) and coma by 0.1 ± 0.1 μm (P < .001); spherical aberration did not change significantly. The severity of self-reported visual symptoms decreased postoperatively. Scatter, corneal HOAs, and residual refraction were not correlated with the degree of visual symptoms. On linear regression analysis, residual refraction was a significant predictor of UDVA (1 day: adjusted R2 = 0.16, P = .02; 3 months: adjusted R2 = 0.55, P < .001). Scatter and corneal HOAs were not associated with postoperative UDVA. Conclusions Despite statistically significant changes in scatter and corneal HOAs, the severity of self-reported visual symptoms decreased postoperatively. Residual refraction was a good predictor of postoperative UDVA. Scatter and corneal HOAs had no effect on the postoperative UDVA.