Corneal shape and irregular astigmatism after SMILE and FS-LASIK: 3 years follow-up
Session Details
Session Title: Presented Poster Session: Keratorefractive Results II
Venue: Poster Village: Pod 2
First Author: : A.Lazaridis GREECE
Co Author(s): : H. Sideroudi G. Labiris A. Messerschmidt-Roth W. Sekundo V. Kozobolis
Abstract Details
Purpose:
The study was took place in Department of Ophthalmology at University Hospital of Alexandroupolis, Greece
Setting:
To compare corneal curvatures, asphericity and induced irregular astigmatism (asymmetry and irregularities), 3 years after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) surgery.
Methods:
Thirty-two eyes which underwent SMILE for low to moderate myopia and myopic astigmatism, were compared to an equal number of eyes treated with FS-LASIK. The groups were matched-adjusted for age and preoperative spherical equivalent. Scheimpflug images were obtained preoperative and 3-year postoperative. Uncorrected visual acuity, corrected distance visual acuity (CDVA), Fourier analysis of keratometric derived parameters (Spherical Component, Regular Astigmatism, Asymmetry and Irregularity), curvature data and asphericity at 6mm, all for anterior and posterior corneal surface were evaluated and compared.
Results:
Preoperative spherical equivalent was -5.26D in SMILE group and -4.85D in FS-LASIK group (p=0.51). Both groups presented significant postoperative differences in corneal curvatures (in the central 3mm zone), asphericity and irregular astigmatism of the anterior corneal surface (p<0.0001), but not of the posterior (p>0.54). SMILE group presented higher spherical component of the anterior corneal surface in the mid-periphery (2mm and 3mm zone) compared to FS-LASIK (p<0.001). Asphericity after SMILE was lower for the anterior corneal surface compared to FS-LASIK (p<0.001). However, both methods induced approximately equal amount of asymmetry and irregularities in both corneal surfaces (p>0.18).
Conclusions:
Three years postoperatively, SMILE seems to preserve corneal asphericity compared to FS-LASIK due to different principles for corneal reshaping and biomechanical response. However, both groups present non-significant differences in the induced irregular astigmatism, in low and moderate myopia.
Financial Disclosure:
NONE
