Abstract
Purpose :
To analize high-order aberrations (HOA) before and 1 week, 1 month and 3 months after Small Incision Lenticule Extraction (SMILE) refractive surgery.
To quantify the change in uncorrected visual acuity (UCVA) after SMILE.
Methods :
Prospective, analytic, observational study design done from January 1st until September 1st 2015. We analyzed logMAR UCVA, and the root mean square (RMS) of several HOA including: comma, trefoil, spherical aberration, defocus and astigmatism using a Hartmann-Shack aberrometer (WaveScan, VisX®). All these measurements were done before SMILE and 1 week, 1 month and 3 months afterwards. SMILE surgery was realized using an Visumax 500 kHz (Carl Zeiss Meditec®) femtosecond laser. All data was emptied to an Excel data sheet and statistical analysis was done using SPSS 21 (IBM®). Student's t was used to compare HOA before and after surgery and Pearson's test was used to assess the correlation between the study's variables.
Results :
71 eyes of 37 patients were included. Mean age at first visit was 28 years. An increase in HOA RMS was found after surgery at all time points evaluated (p<0.05). There was a decrease in defocus, astigmatism and UCVA logMAR (p<0.05). Both trefoil and spherical aberration were not statistically significant modified. We found a positive correlation between the degree in astigmatism with the flap diameter (r=0.661, p<0.0001) and with the optical zone (r=0.661, p=0.000007). A negative correlation was found between UCVA logMAR and HOA RMS and spherical aberration (p=0.044 and p=0.004, respectively).
Conclusions :
SMILE surgery entailed an statistically significant increase in HOA RMS, coma and a decrease in defocus and astigmatism at a week, 1 month and 3 months postoperatively. All included patients in this study achieved an UCVA logMAR of 0.09 or better at 3 months. We believe that SMILE is an efficient refractive technique with a mild induction of HOA RMS and comma after surgery that mantains stable at least after 3 months.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.