Skip to main content
Journal of Refractive Surgery, 2012;28(12):865–871
Published Online: by:144



To study the influence of patient- and surgery-related parameters on the predictability, efficacy, and safety of small-incision lenticule extraction (SMILE) for treatment of myopia.


This prospective, clinical quality, control study comprised 670 eyes from 335 patients with myopia up to −10.00 diopters (D) (spherical equivalent refraction) and astigmatism up to 2.00 D treated with SMILE in both eyes and followed for 3 months.


Preoperative mean spherical equivalent refraction was −7.19±1.30 D. In eyes with emmetropia as the target refraction, 84% obtained uncorrected distance visual acuity ⩽0.10 logMAR (20/25 or better Snellen equivalent) at 3 months. Mean corrected distance visual acuity (CDVA) improved from −0.03 to −0.05 logMAR (P<.01). Two or more lines of CDVA were lost in 2.4% (16 eyes). The achieved refraction was 0.25±0.44 D less than attempted after 3 months, and 80% (537 eyes) and 94% (631 eyes) were within ±0.50 and ±1.00 D of attempted correction, respectively. Multiple linear regression analyses revealed that spherical equivalent refraction undercorrection was predicted by increasing patient age (0.10 D per decade; P<.01) and steeper corneal curvature (0.04 D per D; P<.01). Safety and efficacy of the procedure were minimally affected by age, gender, and simultaneous cylinder correction.


Undercorrection of 0.25 D and small effects of patient age and corneal curvature suggest that the standard nomogram for SMILE need only minor adjustments. This study suggests that safety and efficacy are not influenced to any clinically significant degree by easily discernible patient factors.

  • 1.Sekundo W, Kunert KS, Blum M. Small incision corneal refractive surgery using the small incision lenticule extraction (SMILE) procedure for the correction of myopia and myopic astigmatism: results of a 6 month prospective study. Br J Ophthalmol. 2011; 95(3):335–339.10.1136/bjo.2009.174284

    Crossref MedlineGoogle Scholar
  • 2.Shah R, Shah S, Sengupta S. Results of small incision lenticule extraction: all-in-one femtosecond laser refractive surgery. J Cataract Refract Surg. 2011; 37(1):127–137.10.1016/j.jcrs.2010.07.033

    Crossref MedlineGoogle Scholar
  • 3.Toda I. LASIK and the ocular surface. Cornea. 2008; 27(Suppl 1):S70–S76.10.1097/ICO.0b013e31817f42c0

    Crossref MedlineGoogle Scholar
  • 4.Kim HJ, Silverman CM. Traumatic dislocation of LASIK flaps 4 and 9 years after surgery. J Refract Surg. 2010; 26(6):447–452.10.3928/1081597X-20090710-03

    LinkGoogle Scholar
  • 5.Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for ectasia after corneal refractive surgery. Ophthalmology. 2008; 115(1):37–50.10.1016/j.ophtha.2007.03.073

    Crossref MedlineGoogle Scholar
  • 6.Sekundo W, Kunert K, Russmann C, et al.First efficacy and safety study of femtosecond lenticule extraction for the correction of myopia: six-month results. J Cataract Refract Surg. 2008; 34(9):1513–1520.10.1016/j.jcrs.2008.05.033

    Crossref MedlineGoogle Scholar
  • 7.Blum M, Kunert K, Schröder M, Sekundo W. Femtosecond lenticule extraction for the correction of myopia: preliminary 6-month results. Graefes Arch Clin Exp Ophthalmol. 2010; 248(7):1019–1027.10.1007/s00417-009-1293-1

    Crossref MedlineGoogle Scholar
  • 8.Vestergaard A, Ivarsen A, Asp S, Hjortdal J. Femtosecond (FS) laser vision correction procedure for moderate to high myopia: a prospective study of ReLEx flex, and comparison with a retrospective study of FS-laser in situ keratomileusis [published online ahead of print April 18, 2012]. Acta Ophthalmol. doi:

    Google Scholar
  • 9.Vestergaard A, Ivarsen A, Asp S, Hjortdal J. ReLEx smile for moderate to high myopia: a prospective study of predictability, safety and patient satisfaction. J Cataract Refract Surg. 2012; 38(11):2003–2010.10.1016/j.jcrs.2012.07.021

    Crossref MedlineGoogle Scholar
  • 10.Kim WS, Jo JM. Corneal hydration affects ablation during laser in situ keratomileusis surgery. Cornea. 2001; 20(4):394–397.10.1097/00003226-200105000-00011

    Crossref MedlineGoogle Scholar
  • 11.Huang D, Stulting RD, Carr JD, Thompson KP, Waring GO. Multiple regression and vector analyses of laser in situ keratomileusis for myopia and astigmatism. J Refract Surg. 1999; 15(5):538–549.

    LinkGoogle Scholar
  • 12.Liyanage SE, Allan BD. Multiple regression analysis in myopic wavefront laser in situ keratomileusis nomogram development. J Cataract Refract Surg. 2012; 38(7):1232–1239.10.1016/j.jcrs.2012.02.043

    Crossref MedlineGoogle Scholar
  • 13.Chiang PK, Hersh PS. Comparing predictability between eyes after bilateral laser in situ keratomileusis: a theoretical analysis of simultaneous versus sequential procedures. Ophthalmology. 1999; 106(9):1684–1691.10.1016/S0161-6420(99)90390-1

    Crossref MedlineGoogle Scholar

We use cookies on this site to enhance your user experience. For a complete overview of all the cookies used, please see our privacy policy.