Small Incision Lenticule Extraction (SMILE) for the Correction of High Myopia With Astigmatism

Abstract

To report the outcomes of small incision lenticule extraction (SMILE) for high myopia between −9.00 and −14.00 diopters (D). This was a prospective study of SMILE for high myopia using the VisuMax femtosecond laser (Carl Zeiss Meditec). Inclusion criteria were attempted spherical equivalent refraction (SEQ) between −9.00 and −14.00 D, cylinder up to 7.00 D, corrected distance visual acuity (CDVA) of 20/40 or better, age 21 years or older, and suitable for SMILE. The sub-lenticule thickness was 220 µm or greater, and the total uncut stromal thickness was 300 µm or greater. Patients were to be followed up for 1 year. Standard outcomes analysis was performed using 12-month data where available or 3-month data otherwise. Of 187 eyes treated, data were available at 12 months for 181 eyes (96.8%) and 3 months for 4 eyes (2.1%), and 2 eyes (1.1%) were lost to follow-up. Mean attempted SEQ was −10.55 ± 1.00 D (range: −9.00 to −12.99 D). Mean cylinder was −1.19 ± 0.83 D (range: 0.00 to −4.00 D). Preoperative CDVA was 20/20 or better in 73% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 57% and 20/25 or better in 82% of eyes. Mean SEQ relative to target was −0.22 ± 0.48 D (range: −1.63 to +1.38 D), 66% ± 0.50 D and 93% ±1.00 D. Mean SEQ 12-month change was −0.08 ± 0.34 D (range: −1.75 to +0.88 D). There was loss of one line of CDVA in 4% of eyes, and no eyes lost two or more lines. Contrast sensitivity was unchanged. Patient satisfaction was 8 or more out of 10 in 94% and 6 or more in 99% of patients. Outcomes of SMILE for myopia greater than −9.00 D at 3 to 12 months showed excellent efficacy, safety, stability, and predictability, with high patient satisfaction. [J Refract Surg. 2022;38(5):262–271.]