The correlation between refractive status and changes in higher-order aberration after small incision lenticule extraction for myopia and myopic astigmatism correction

Purpose: To evaluate the correlation between patient’s refractive status and changes in high-order aberration after small incision lenticule extraction in correcting myopia and myopic astigmatism. Methods: Prospective, longitudinal observational study. Sixty-six eyes from 33 myopia or myopic astigmatism patients were enrolled in this study. Patients uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refractive status, central corneal thickness, corneal refractive power, optical zone, lenticule thickness and 3 higher-order aberration values in Zernike polynomial (spherical aberration, coma and total root mean square) were recorded before the surgery and at 3-month follow-up. Results: At 3-month follow-up, 100% of eyes achieved 20/20 uncorrected visual acuity. There were statistically significant increases of spherical aberration, coma and total root mean square after the surgery; with post-operation changes of spherical aberration, coma and total root mean square being 0,1689 ± 0,0867 µm, 0,1771 ± 0,0941 µm and 0,3271 ± 0,1035 µm, in order (p < 0,001). A linear correlation was found between pre-operation spherical equivalent with changes of spherical aberration (R = 0,449; p < 0,01) and total root mean square (R = 0,229; p = 0,05). Conclusion: Small incision lenticule extraction results in good visual outcome, however still induces increase of higher-order aberration, especially in patients with high refraction.