Compared changes of higher order aberrations after LASIK and femtosecond small incision lenticule extraction in correction of myopia and myopic astigmatism

Session Details

Session Title: SMILE for Myopia II

Session Date/Time: Wednesday 17/09/2014 | 08:00-09:30

Paper Time: 09:00

Venue: Capital Hall B

First Author: : O.Kostin RUSSIA

Co Author(s): :    S. Rebrikov   A. Ovchinnikov   A. Stepanov        

Abstract Details

Purpose:

Comparative estimation of the thickness of the corneal flap formed with Moria microkeratome and VisuMax femtosecond laser, refraction, visual acuity, contrast sensitivity and higher order aberrations after LASIK and SMILE operations for myopia and myopic astigmatism correction.

Setting:

IRTC Eye Microsurgery Ekaterinburg Center

Methods:

Two groups 20 eyes in each were enrolled. In group 1 standard LASIK operation was performed. In group 2 SMILE operation was performed. Besides standard examinations, wavefront (WF) aberrations in Malacara notation were measured with WASCA aberrometer (CarlZeissMeditec, Germany) with drug-free pupil diameter of 6 mm. Measurement of corneal flap thickness at the center of the cornea and at the distance of 1, 2 and 3 mm from the center was performed in both groups with Visante OCT (CarlZeissMeditec) optical coherence tomograph in HighResolutionCornealQuad and HighResolutionCornealSingle modes. Contrast sensitivity was performed in both groups with CSV-1000 device (VECTORVISION).

Results:

Uncorrected visual acuity before the operation in groups 1 and 2 was 0.05 ± 0.07; 0.05 ± 0.03 and after the operation it made 0.99 ± 0.05; 0.98 ± 0.03 (p>0.05). Spherical equivalent (SE) before the operation in groups 1 and 2 was -4.13 ± 2.08D; -4.19 ± 1.29D and after the operation it made 0.02 ± 0.16 D; 0.08 ± 0.16 D (p>0.05). Corrected visual acuity before the operation in groups 1 and 2 was 0.98 ± 0.05; 0.99 ± 0.02 and after the operation it made 0.99 ± 0.07; 0.9 ± 0.12 (p>0.05). The value of spheric aberration of the eyes in groups 1 and 2 before the operation was 0.12 ± 0.19 µm; -0.17 ± 0.25 µm, after the operation it has increased negatively up to -0.53 ± 0.30 µm; -0.26 ± 0.15 µm. In group 2 unlike group 1 the increase of spheric aberration was not statistically significant.

Conclusions:

VisuMax femtosecond laser performs correction of myopia and myopic astigmatism using SMILE operation, providing a possibility to form corneal flaps with accurately preset parameters unlike mechanical microkeratome. Use of SMILE operation with extraction of corneal lenticule provides an increase of visual acuity up to the level of preoperative best corrected visual acuity with an insignificant induction of higher order aberrations and restoration of preoperative contrast sensitivity values under mesopic conditions up to the third month after the operation.

Financial Interest:

NONE