Four different deepness small incision lenticule extraction (SMILE) procedure for the correction of myopia and myopic astigmatism

Poster Details

First Author: PaulaVerdaguer SPAIN

Co Author(s):    Jose L. Güell   Daniel Elies   Oscar Gris   Felicidad Manero     

Abstract Details

Purpose:

To evaluate the feasibility of performing the 4 different deepness of lenticule (130, 140, 150 and 160 µm) of myopic femtosecond lenticule extraction (FLEx) through a small incision using the small incision lenticule extraction (SMILE) technique.

Setting:

: Instituto de Microcirugia Ocular (IMO), Barcelona, Spain.

Methods:

Retrospective, comparative, non-randomized clinical trial including 70 eyes of 35 patients with myopia with and without astigmatism with a mean follow-up period of 1 month. Thirty-four eyes were performed with 130µm deepness lenticule, 12 eyes with 140µm, 12 eyes with 150µm and 12 eyes with 160 µm deepness lenticule. The patients’ mean age was 31.49 years (range 23 to 46 years). Their preoperative mean cylinder (CYL) was -0.66D (range 0 to -2.50D), sphere (SPH) was -4.49D (range -1.75 to -7.75D) and mean pachimetry was 575.92µm (range 511 to 641µm) with a similar distribution in between groups. A refractive lenticule of intrastromal corneal tissue was cut using the Carl Zeiss Meditec AG VisuMax femtosecond laser system using different deepness of the non-refractive lenticule. Immediately a 4mm in arc length small ‘pocket’ incision was created by the laser system. Thereafter, the lenticule was manually dissected with a spatula and removed through the incision using modified McPherson forceps. Main outcome measures; Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA) after mean 1 month, objective and manifest refraction, spherical equivalent (SE) as well as slit-lamp examination and side effects.

Results:

All patients gained UCVA after the SMILE procedure (mean UCVA 0.76) (p≥0.05).UCVA≥20/25 70% of patients. Mean all groups residual SE was -0.22D(standard deviation (SD 0.4), mean all groups residual CYL was 0.20D (SD 0.55) and mean all groups residual SPH was -0.07 (SD 0.43) without statistically difference between the 4 groups (p≥0.05). We didn’t observe any complications after the surgery in none of the 4 groups (p≥0.05). We didn’t find statistically difference between the different deepness lenticule treatment in 7.1% of patients that had a decrease of 1 line BSCVA and 2.8% of patients that had a decrease of 2 lines BSCVA (p≥0.05) during the first few weeks after the procedure.

Conclusions:

SMILE is a promising, effective, predictable and safe new flapless minimally invasive refractive procedure to correct myopia and astigmatism. As far as we know, this is the first clinical study in which analyzed the different SMILE deepness techniques. We have not observed difference in visual acuity, in refractive outcomes and in complications using the 4 different deepness of SMILE procedure. We have the limitation of the number of patients in 140, 150 and 160 µm deepness. Further comparative studies are required to support these conclusions in order to decide the ideal depth for primary and secondary smile procedures. FINANCIAL INTEREST: NONE