LASIK Versus SMILE for Myopic Conditions
By Lynda Seminara
Selected By: Stephen D. McLeod, MD
Journal Highlights
Ophthalmology, June 2020
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LASIK remains the most popular refractive treatment for myopia and myopic astigmatism, but small-incision lenticule extraction (SMILE) is increasing in popularity. Ang et al. performed a paired-eye noninferiority trial to compare the two procedures objectively. They found that both had good refractive predictability and similar safety indices at three and 12 months.
This prospective masked study was conducted at the Singapore National Eye Centre. Consecutive patients (recruited from May 2014 to November 2016) were assigned randomly to receive SMILE in one eye and LASIK in the other, with both procedures provided on the same day by a single surgeon. The prespecified primary outcome was refractive predictability three months after surgery; secondary outcomes included efficacy and safety results.
Ultimately, 70 eligible patients were assessed (mean age, 28 years; all Asian; 64% female). Preoperatively, there was little difference in spherical equivalence (SE) between eyes (‒05.3 ± 1.8 D vs. ‒5.2 ± 1.7 D; p = .87). Both procedures had high three-month predictability: 99% of SMILE eyes and 97% of LASIK eyes achieved SE within ±1 D of attempted correction. However, the high performance of both procedures suggested that a noninferiority margin of ±1 D was too great to offer a meaningful distinction. Additional analysis looking at a margin of ±0.5 D indicated that at three months, 87% of SMILE eyes and 92% of LASIK eyes achieved SE within ±0.5 D of attempted correction.
Uncorrected distance visual acuity (UDVA) of 20/40 or better was achieved in 100% of both groups, and UDVA of 20/20 or better was attained in 84% of SMILE eyes, versus 87% of LASIK eyes. Through 12 months, similarity was sustained in predictability (SE within ±1 D of attempted correction: 99% for both SMILE and LASIK), efficacy (UDVA of 20/20 or better: 85% vs. 83%), and safety (index: 1.15 ± 0.20 for both).
The authors noted that neither procedure resulted in major complications. Nevertheless, they emphasize that SMILE is a challenging procedure that necessitates additional surgical training. (Also see related editorial by Thomas M. Lietman, MD, in the same issue.)
The original article can be found here.