ESCRS - FPM11.12 - Effect Of Smile Enhancement And Femtosecond Lasik On Changes In Higher-Order Aberrations And Corneal Densitometry

Effect Of Smile Enhancement And Femtosecond Lasik On Changes In Higher-Order Aberrations And Corneal Densitometry

Published 2022 - 40th Congress of the ESCRS

Reference: FPM11.12 | Type: Free paper | DOI: 10.82333/65s3-km91

Authors: Valencia Foo* 1 , Yu-Chi Liu 1 , Marcus Ang 1 , Myint Htoon Hla 2 , Darren Ting 3 , Jodbhir Mehta 1

1Singapore National Eye Centre,Singapore,Singapore;Singapore Eye Research Institute,Singapore,Singapore, 2Singapore Eye Research Institute,Singapore,Singapore, 3Ophthalmology,Academic Ophthalmology, School of Medicine, University of Nottingham,Nottingham,United Kingdom

Purpose

To compare differences in corneal densitometry (CD) and higher-order aberrations (HOA) in eyes which underwent Small Incision Lenticule Extraction (SMILE) and Femto-second Laser-assisted stromal in-situ keratomileusis (FS-LASIK) for the treatment of myopia and myopic astigmatism at post-operative month 3, 6 and 12, and to evaluate their changes in a separate cohort of post-SMILE enhancement eyes.

Setting

Prospective, randomised, paired-eye, clinical trial. Consecutive eligible participants were randomised to undergo SMILE or FS-LASIK in either eye.

Methods

 Patients were treated in each eye using the VisuMax (Carl Zeiss Meditec, Jena, Germany) 500-kHz femtosecond laser system. Excimer ablation was subsequently performed using the WaveLight EX500 excimer laser (Alcon Laboratories, Inc, Fort Worth, TX) in the eye for FS-LASIK. Main outcome measures were CD and HOA at preoperative, 3, 6 and 12 months. A separate cohort of consecutive SMILE patients who underwent enhancement via photorefractive keratectomy (PRK) with mitomycin C (MMC) had CD and HOA changes evaluated as well.

Results

For CD, no significant differences were found between SMILE and FS-LASIK at month 12. For HOA measured by wavefront aberrometry, both SMILE and FS-LASIK had increased total root mean square (RMS) HOA, spherical aberration (SA), vertical coma and secondary astigmatism at month 12. SMILE had an additional increase in vertical quatrefoil, and FS-LASIK had an increase in horizontal coma at month 12. FS-LASIK had higher SA than SMILE, while SMILE had higher vertical quatrefoil than FS-LASIK at month 12. Post-SMILE enhancement had significantly increased central and posterior zone CD compared to post-primary SMILE at 2 years post-enhancement. Total RMS HOA, LOA and SA were increased post-SMILE enhancement compared to post-primary SMILE.

Conclusions

In this randomised paired-eye trial, SMILE induced lower SA but higher vertical quatrefoil than FS-LASIK at 1 year. Both SMILE and FS-LASIK had similar increases in RMS HOA, vertical coma and secondary astigmatism up to 1 year. There were no differences in CD between both groups. High myopes had greater SA than low myopes in both SMILE and FS-LASIK. SMILE enhancement additionally induced increased central and posterior CD as well as RMS HOAs and SA compared to primary SMILE.