Fourier analysis of keratometric data for quantitative evaluation of corneal irregular astigmatism after SMILE and comparison to FS-LASIK

Session Details

Session Title: Refractive
Session Date/Time: Friday 15/02/2019 | 08:30-10:00
Paper Time: 09:22
Venue: Room MC3

First Author: A. Lazaridis GREECE
Co Author(s): H. Sideroudi  G. Labiris  W. Sekundo  V. Kozobolis  A. Messerschmidt-Roth     

Abstract Details

Purpose:

Evaluation of Spherical Component (SC), Regular (RA) and Irregular Astigmatism (IA, i.e. Asymmetry and Irregularities) 3 years after SMILE and comparison to FS-LASIK

Setting:

Department of Ophthalmology, Medical School, Democritus University, Alexandroupolis, Greece and Department of Ophthalmology, Philipps University of Marburg, Germany

Methods:

Thirty-two eyes of 21 patients who underwent SMILE for myopia and astigmatism were compared to 32 eyes of 21 patients treated with FS-LASIK. Scheimpflug images were obtained preoperatively and 3 years postoperatively. Fourier analysis of keratometric derived parameters (SC, RA, Asymmetry and Irregularity) of anterior, posterior and total cornea from the central 2mm zone, from 3 concentric rings (2-4mm, 4-6mm and 6-8mm ring) around apex and from the entire 8mm zone were evaluated and compared.

Results:

After FS-LASIK, over the 8mm zone the RA, IA of the anterior cornea increased significantly (P≤0.002), while SMILE induced an insignificant increase of RA and Asymmetry (P≥0.276) and a decrease of Irregularities (P=0.770). At the 8mm zone of the posterior cornea, the Irregularities increased significantly (P=0.027) after FS-LASIK, while SMILE induced no significant changes of the examined variables (P≥0.347). RA and IA of the total cornea increased significantly after FS-LASIK (P≤0.001), while SMILE induced an insignificant increase of RA and Asymmetry (P≥0.092) and a significant decrease of Irregularities (P<0.001).

Conclusions:

Three years postoperatively, FS-LASIK resulted in greater increase of RA and Irregularities and induced a greater flattening of the mid-periphery (6-8mm annulus) of the anterior and total cornea compared to SMILE. The posterior cornea remained unaffected after SMILE while more Irregularities were induced after FS-LASIK at the mid-periphery and over the 8mm posterior corneal zone.

Financial Disclosure:

... has significant investment interest in a competing company