AIM: To observe the surgical results of large astigmatism with small incision lenticule extraction(SMILE)for 2a.

METHODS: Totally 33 eyes of 17 consecutive patients were enrolled in this retrospective study, aged from 18 to 36 years old, which included 24 eyes of 12 patients with astigmatism within -3.50D to -4.00D and 9 eyes of 5 patients within -4.25D to -5.00D, 7 eyes of 4 patients with sphere within 0 to +1.00D and 26 eyes of 13 patients within -1.00D to 0. Intended cap diameters was 7.3-7.5mm, lenticule diameter was 6.6-6.8mm, the thickness of cap was 120μm, the surgical incision was 2mm. We observed the results after 1d, 1wk, 1, 3, 6mo, 1 and 2a. Preoperative best corrected visual acuity, spherical equivalent refraction, postoperative uncorrected visual acuity, SimK equivalent value and SimK value was observed.

RESULTS: Compared with preoperation, uncorrected visual acuity showed significant difference statistically at 1d postoperatively(P<0.05). Compared with 1wk postoperatively, uncorrected visual acuity showed no significant difference statistically at postoperative 1, 3, 6mo, 1 and 2a(P>0.05). Uncorrected visual acuity did not increase or decrease more than two lines. The target diopter was +0.25D. Compared with 1d postoperatively, the spherical equivalent refraction and residual astigmatism showed no significant difference statistically at each postoperative period(P>0.05). postoperative SimK equivalent value and SimK value difference showed no significant difference statistically compared with each postoperative period(P>0.05).

CONCLUSION: It is both safe, effective, predictable and stable to correct large astigmatism with SMILE by long-term observation, postoperative 2a. The corneal morphology is good and worthy of clinical application.