LASIK-induced corneal aberrations measured with a point-source colour light-emitting diode (LED) topographer

Session Details

Session Title: Refractive
Session Date/Time: Friday 10/02/2017 | 10:30-12:30
Paper Time: 10:36
Venue: Brussels Room 0.4

First Author: M. Morral SPAIN
Co Author(s): D. Elies  F. Manero   J. Guell           

Abstract Details

Purpose:

To evaluate induced corneal aberrations after myopic LASIK performed with the MEL 90 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) and the Triple-A profile with a 500-Hz pulse rate, using a point-source color light-emitting diode (LED) topogapher (Cassini, iOptics, Ophtec B.V., Groningen, The Netherlands).

Setting:

Instituto de Microcirugia Ocular, Barcelona, Spain

Methods:

Prospective, consecutive study including patients undergoing myopic LASIK with the VisuMax femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany)ﾠand the Triple-A profile of the MEL 90. Flap thickness was between 90-100 microns and optical zone was between 6.5 and 6.7 mm. Corneal aberrations up to the 4th order were measured using the Cassini color-LED topographer before and 3 months after surgery. Mean change in corneal aberrations was calculated. Standard outcomes analysis was also performed. A p value < 0.05 was considered statistically significant (paired Student t test).

Results:

Forty eyes of 20 patients were evaluated. Preoperatively, mean spherical equivalent (SEQ) was -4.06 ﾱ 1.53 D and mean cylinder was -0.78 ﾱ 0.56 D. Postoperative SEQ and cylinder were ﾱ 0.50 D in 100% of eyes. Postoperative uncorrected distance visual acuity was 20/20 in 93.75% of eyes. None of the eyes lost any line of corrected distance visual acuity. Mean change of 3rd and 4th order corneal aberrations was as follows: Z(-4,0) 0.085ﾱ0.253(P=0.004); Z(3,-1) 0.124ﾱ0.392(P=0.042); Z(-3,1) 0.020ﾱ0.171(p=0.570); Z(3,-3) -0.024ﾱ0.321(p=0.7536); Z(3,3) 0.010ﾱ0.070(p=153); Z(4,-4) 0.001ﾱ0.046(p=0.910); Z(4,-2) 0.014ﾱ0.044(p=0.449); Z(-4,2) -0.015ﾱ0.266(p=0.993); and Z(-4,4) 0.037ﾱ0.156(p=0.732).

Conclusions:

The MEL 90 excimer laser using the Triple-A ablation profile with a 500-Hz pulse rate was found to achieve a high efficacy and safety for myopia up to -8.00 D and cylinder up to 2.00 D. The Cassini color-LED topographer demonstrated a statistically significant increase of spherical aberration (Z(-4,0)) and vertical coma (Z(3,-1)), but below tolerable levels. None of the patients described clinically significant visual disturbances.

Financial Disclosure:

receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented