Abstract
Purpose: :
Descemet's stripping and automated endothelial keratoplasty (DSAEK) is an increasingly popular surgical method in cases of endothelial pathologies. A posterior corneal lamella is dissected preceding the operation. So far, automated dissection was performed using a microkeratome on a corneo-scleral disc in an artificial anterior chamber. Recently, femtosecond laser assisted preparation of the lamella was described from the complete globe. We describe a technique for preparation of the posterior corneal lamella in organ-cultured corneo-scleral discs using a femtosecond laser.
Methods: :
Corneo scleral discs were fixed in an artificial anterior chamber (Barron Artificial Anterior Chamber, Katena, Denville, USA). A treatment pack of a femtosecond laser (VisuMax, Carl Zeiss Meditec, Jena, Germany) was modified and attached to the laser. Then, a deep stromal cut was performed parallel to the endothelium. The corneal lamellae were separated with a blunt spatula and the discs were organ-cultured again. Endothelial cells were counted before and after the procedure using an inverted light microscope (Nicon Eclipse TE 200-S, Nicon Instech, Kawasaki, Japan). Thickness of the posterior corneal lamella was measured inside the culture flasks using optical coherence tomography (Visante OCT, Carl Zeiss Meditec, Jena, Germany). Samples of the culture medium were tested for bacterial growth.
Results: :
We observed a mild decrease in endothelial cell count. Optical coherence tomography rendered good visualisation of the interface in the cultured donor cornea with little variation in posterior lamella thickness. Bacterial growth from the culture medium samples was not observed.
Conclusions: :
To our knowledge, we present the first description of preparing a posterior lamella in a corneo-scleral disc using the VisuMax femtosecond laser. This procedure can easily be integrated in cornea bank processes. It supplies the surgeon with valuable information about thickness, homogeneity, endothelial cell count and contamination status of the dissected lamella before the transplantation. Availability of pre-cut corneo-scleral discs from cornea banks will allow the DSAEK procedure to be performed by ophthalmic surgeons lacking adequate dissection devices.
Keywords: cornea: endothelium • cornea: storage • cornea: clinical science