The results of a pivotal clinical trial are out, paving the way for expanded FDA approval of small incision lenticule extraction (SMILE) for the correction of myopia and astigmatism.1
Since 2011, SMILE has evolved from a treatment for myopia to one for myopia with astigmatism up to –0.50 D—and now to one for correction of myopia with or without astigmatism up to –3.0 D. The flapless treatment, which reshapes the cornea using only a femtosecond laser, proved safe and effective and demonstrated predictable correction over the trial duration of 12 months, and patients achieved refractive stability between three and six months.
In the approved range, the procedure can be recommended to patients as an alternative method of refractive vision correction, said Jon G. Dishler, MD, at Dishler Laser Institute in Greenwood Village, Colorado.
The study. Between March 2015 and July 2016, 357 patients (357 eyes) underwent SMILE in one eye. (Most fellow eyes received excimer laser treatment.) Preoperative sphere ranged between –1.00 and –10.00 D, with manifest spherical equivalent (MSE) up to –11.50 D and refractive cylinder up to –3.0 D.
At 12 months, 95.3% of all eyes were within 0.50 D of emmetropia, 89.0% achieved uncorrected distance visual acuity (UDVA) of 20/20 or better, and 99.0% had UDVA of 20/40 or better. In addition, MSE went from –5.39 at baseline to –0.01 D, and average refractive cylinder went from –1.53 D to 0.18 D.
Complications. Three intraoperative events were associated with difficult lenticule removal and resultant cap tear. All resolved without sequelae at postoperative day one, and patients completed the study with UDVA of 20/20 or better. Eight adverse events occurred postoperatively; none had significant consequences.
Looking ahead. SMILE still does not address hyperopia, mixed astigmatism, or very high levels of astigmatism, Dr. Dishler noted. “But I would estimate that well over 90% of patients in search of refractive vision correction could be served by this procedure.” He noted that the U.S. military is currently completing a SMILE study, and he added, “a procedure with rapid recovery without the limitations of a corneal flap is appealing to both patients and doctors.”
1 Dishler JG et al. Ophthalmology. Published online Jan. 14, 2020.
Relevant financial disclosures—Dr. Dishler: Carl Zeiss: C.
For full disclosures and the disclosure key, see below.
Full Financial Disclosures
Dr. Dishler Carl Zeiss: C.
Dr. Douglas Horizon Therapeutics: C.
Mr. Han Support from the University of Queensland Research Training Scholarship and Queensland Institute of Medical Researcher Berghofer PhD Top Up Scholarship.
Dr. Lam None.
||Consultant fee, paid advisory boards, or fees for attending a meeting.
||Employed by a commercial company.
||Lecture fees or honoraria, travel fees or reimbursements when speaking at the invitation of a commercial company.
||Equity ownership/stock options in publicly or privately traded firms, excluding mutual funds.
||Patents and/or royalties for intellectual property.
||Grant support or other financial support to the investigator from all sources, including research support from government agencies (e.g., NIH), foundations, device manufacturers, and/or pharmaceutical companies.
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