SMILE Procedures With Four Different Cap Thicknesses for the Correction of Myopia and Myopic Astigmatism

To study the feasibility of performing myopic femtosecond small incision lenticule extraction (SMILE) with four different cap thicknesses (130, 140, 150, and 160 μm).

In this retrospective, comparative, non-randomized clinical trial, a refractive lenticule of intrastromal corneal tissue was cut with the VisuMax femtosecond laser system (Carl Zeiss Meditec AG, Jena, Germany) using different depths of the non-refractive lenticule cut. Manifest refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and Objective Scattering Index (OSI) were evaluated. Minimum follow-up time was 1 year.

Ninety-four eyes of 47 patients with myopia with (14 patients) and without (33 patients) astigmatism were treated. One year after the surgery, mean log-MAR UDVA, logMAR CDVA, SE, and OSI were 0.07 ± 0.12, 0.01 ± 0.37, 0.07 ± 0.57, and 0.88 ± 0.17, respectively (P < .05). There were no significant statistical differences in logMAR UDVA, logMAR CDVA, SE, or OSI (P > .05) variables when the different groups were compared for the same periods of time.

No differences in visual acuity, refractive outcomes in optical visual quality, or complications were observed when using SMILE at four different depths.