Posters

Evaluation of donor cornea trephination with a femtosecond-laser with and without application

Poster Details

First Author: G.Schmidinger AUSTRIA

Co Author(s):                        

Abstract Details

Purpose:

Performing corneal trephination for penetrating keratoplasty with a Femtosecond-Laser (FL) has potential benefits over manual trephination. FLAK (Femtolaserassisted keratoplasty) might increase precision in terms of centration and cut-geometry. Potential drawbacks are related to the need of applanation of the tissue during the cut and to the use of high pressure in the artificial anterior chamber. The aim of this trial is to investigate the differences between manual and FL assisted trephination in human donor eyes.

Setting:

Medical University of Vienna

Methods:

Twenty paired human donor corneas have been divided into 4 groups. In the first group, a manual trephination has been performed. The residual eyes were cut with a FL (Ziemer Z8) using the following settings: group 2: standard FL assisted trephination with applanation; group 3: FL assisted trephination with tissue medium in artificial chamber ; group 4: �â�€�œliquid interface�â�€� FL trephination without applanation. All donor corneas where evaluated for preoperative and postoperative pachymetry, sidecut geometry (OCT), circularity (Image J) and folds of the descemet membrane (DM) in the trephined tissue. Descemet folds were graded using the following scale: 0 (no folds), 1 (slight irregularities of the DM), 2 (more than 2 folds) to 3 (severe folds).

Results:

A successful trephination has been achieved in all donor corneas. Corneas trephined with the FL showed slightly less side-cut angulation compared to manual trephined corneas. Corneas of group 4 showed the least side-cut angulation. The pachymetry of the trephined tissue was stable in group 1, increased in group 2 and was stable in group 3 and 4. No differences were found in terms of circularity of the cut. The mean grade of descemet folds was 0.75 in group 1, 1.8 in group 2, 1.5 in group 3 and 0.25 in group 4.

Conclusions:

The use of a FL for donor and recipient trephination can increase precision the cut geometry. A higher degree of descemet folds was seen when tissue was cut using the FL and applanation. The applanation-free FL trephination of corneal tissue significantly increased trephination quality, probably by reducing mechanical stress to the tissue during the cut. Whether the increase in precision of the cut geometry will results in a beneficial patient outcome has to be investigated in a clinical trial.

Financial Disclosure:

NONE