Efficacy, predictability and safety of small incision lenticule extraction (SMILE)

Background: The purpose of this case series is to report the one-year outcomes of small incision lenticule extraction (SMILE) using the VisuMax (R) femtosecond laser. Methods: Two hundred and six patients were recruited for this retrospective, single center study at TRSC International LASIK Center in Bangkok, Thailand. Patients underwent SMILE, whereby an intrastromal lenticule was cut using a femtosecond laser and then manually extracted without the need for flap creation. Outcome measures included refraction, visual acuity and contrast sensitivity evaluation. Patients were treated and followed for one year. Results: SMILE for the correction of low to high myopia was performed on 347 eyes of 206 patients. The mean preoperative spherical equivalent was -4.96 +/- 1.88 diopters (D). On the first day following surgery, for eyes with a piano target refraction (99.14 % of all eyes), uncorrected distance visual acuity (UDVA) was 20/20 or better in 90 % of eyes. At the one week postoperative exam, the mean spherical equivalent was 0.01 +/- 036 D and UDVA was 20/20 or better in 84 % of eyes. After one year follow-up, no eyes showed loss of 2 or more lines of visual acuity and 31 % of eyes gained one or more lines. The photopic contrast sensitivity of SMILE treated eyes at 12 and 18 cycles per degree (cpd) improved from 1.59 and 0.94 preoperatively to 1.6 and 0.98, respectively, after one year. Conclusions: In this series, SMILE using the VisuMax (R) femtosecond laser demonstrated that after one year it is an effective, predictable and safe minimally invasive corneal refractive procedure.