Posters

Comparison of residual astigmatism of 2500 small incision lenticle extractions and 1900 femtolaser-assisted excimer ablations

Poster Details

First Author: A.Viljanen FINLAND

Co Author(s):    H. Koskela                    

Abstract Details

Purpose:

This study compares residual astigmatism of small incision lenticle extraction (SMILE) and femtolaser-assisted LASIK (fLASIK).

Setting:

This is a retrospective two-center observation study in Medilaser Coronaria, Finland.

Methods:

A total of 2238 subjects with mean age of 34 years, 58% females, were treated. 2538 eyes of SMILE (mean cylinder 0.75 D) and 1929 eyes of fLASIK (mean cylinder 0.80 D) were compared. The lasers were VisuMax (Carl Zeiss Meditec AG, Germany), and Amaris (Schwind, Germany). Parameters are residual cylinder power (CYLP), absolute value of astigmatism vector error angle (VEA), and uncorrected visual acuity (UCVA) after laser. Linear mixed model was used in statistical analysis. Subgroups of baseline cylinder power 0-1D, 1-2D, 2-3D, 3-4D, and 4-5D were analyzed. Follow-up visits were 1 and 6 months.

Results:

Baseline CYLP was higher in fLASIK group (p<0.05). CYLP was higher in SMILE group at 1 month (0.21D vs. 0.14D, p<0.001), and at 6 months (0.29D vs. 0.22D, p<0.001). VEA was higher in SMILE group at 1 month (9° vs. 5°, p<0.001), and at 6 months (14° vs 9° p<0.001). In cylinder power of 4-5D, CYLP and VEA were equal in both follow-up visits. UCVA with fLASIK was better in 1-2D group at 1 month and 2-3D group at 6 months, and equal in other subgroups. UDVA correlated significantly with CYLP and VEA in both follow-ups.

Conclusions:

In this study, residual cylinder power and astigmatism error angle after fLASIK was statistically lower compared to SMILE, and statistically equal in higher cylinder power corrections. Visual acuity differences were found in some astigmatism subgroups. Observed differences were within measurement error and clinical differences were small. UDVA correlates with precision of astigmatism correction. Baseline cyclotorsion correction was available in fLASIK, but not SMILE technique.

Financial Disclosure:

None