Posters

Correction of corneal irregularities with two different excimer laser systems

Poster Details

First Author: S.Pieh AUSTRIA

Co Author(s):    G. Schmidinger   C. Skorpik                 

Abstract Details

Purpose:

Higher-order aberration corrections for highly aberrated corneas require a small laser spot with a maximum diameter of 1.0 mm and precise positioning of each laser spot during ablation. In this prospective study, two different laser systems were compared in terms of their ability to correct higher order aberrations.

Setting:

Medical University Vienna

Methods:

Two groups of 20 highly aberrated eyes with an RMS HOA error of 1.0 to 4.0 μm were treated with either the Micron M7 (Excelsius Medical) with a 0.7 mm laser spot or the Amaris 750 (Schwind Eye-Tech-Solutions GmbH & Co. KG) with a laser spot of 0.54 mm. For the calculation of the ablation profile, the corneal topography evaluated with the Casia I (Tomey) was used in the first group, that with the Keratronscout (Optikon) for the second group. The results were evaluated by comparing the preoperative and postoperative corneal topography in both groups with the Keratronscout (Optikon).

Results:

The Amaris Excimer Laser showed significant better results for the capability to reduce higher order aberrations. The results are presented in graphs for the cylinder of the corneal surface as a deviation from the calculated preoperative residual cylinder to the actual postoperatively measured cylinder value. The aberrations of the 3rd and 4th order are described comparatively for both groups as comparison values before and after the treatment.

Conclusions:

Modern excimer laser systems can correct aberrations of the 3rd order as well as the 4th order except the quatrefoil by average of 40 % in one session. The best results are achieved for the correction of the rotationally symmetric spherical aberration of the 4th order.

Financial Disclosure:

None