Effect of femtosecond laser cutting parameters on the results of small incision lenticule extraction

Session Details

Session Title: SMILE: Small Intrastromal Lenticule Extraction I

Session Date/Time: Sunday 11/09/2016 | 08:00-10:00

Paper Time: 08:58

Venue: Hall H1

First Author: : X.Chen NORWAY

Co Author(s): :    A. Stojanovic   M. Olsen   A. Lyngstadaas   S. Enayati   T. Utheim        

Abstract Details

Purpose:

To evaluate the effect of femtosecond laser cutting parameters on the results of small incision lenticule extraction (SMILE) in terms of interface light scattering, cap thickness, and refractive outcome.

Setting:

SynsLaser Kirurgi, Oslo, Norway

Methods:

Fifty-eight right eyes treated by SMILE with programmed cap thickness of 130 µm were divided into two groups according to laser settings: Pulse energy and spot separation were 165 nJ and 4.5 µm in group 1 (n=36) and 125 nJ and 4.2 µm in group 2 (n= 22). Postoperative grading of interface light scattering under slit-lamp microscopy were performed by subjective evaluation of the area presenting light scattering: grade 0: no scattering; grade 1: ≤25%; grade 2: 25-50%; grade 3: 50-75%; and grade 4: 100%. Cap thickness within central 5 mm of horizontal meridian was measured with SD-OCT

Results:

At 3 months postoperatively, for group 1 and 2, the interface scattering grading was 0.9±1.0 and 0.3±0.9 (p<0.05), while clear interface was detected in 33.3% and 86.4% of the eyes. For group 1 and 2, respectively, the cap thickness was 138.9±6.2 µm and 149.4±3.5 µm (p<0.001); the spherical equivalent changed from -4.00±1.84 D to -0.03±0.44 D and from -3.81±2.11 D to -0.04±0.31 D; 83.3% and 95.5% of the eyes were within ±0.5 D of the desired outcome; and 69.4% and 86.4% of the eyes achieved uncorrected distance visual acuity of 20/20.

Conclusions:

This study shows that lower pulse energy with tighter spot improved interface light scattering with possibly better refractive outcome. The femtosecond laser cutting parameters demonstrated a significant influence in the cap thickness.

Financial Disclosure:

NONE