Abstract
Purpose: :
To evaluate technical improvements of a new laser-assisted technique in Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), using the IntraLase® femtosecond laser to prepare the donor endothelial flap and a diode laser to secure it to the recipient cornea by spot welding.
Methods: :
In 5 volunteers suffering from bollous keratopathy and Fuchs’ keratitis, the IntraLase® was used for the preparation of a 100 micron thick, 8.5 mm diameter donor corneal endothelium flap, whose stromal side was then stained with a solution of Indocyanine Green (ICG) used as a photoenhancing chromophore in order to perform tissue welding by pulsed irradiation with a 810 nm diode laser. After a circular-8 mm diameter stripping of the recipient Descemet's membrane and endothelium, the donor flap was positioned in situ by an air bubble. In order to stabilize the endothelial flap, we applied a new and minimally invasive welding procedure, in which we performed a crown of welding spots of 200 micron diameter on the periphery of the flap by irradiating with a fiberoptic probe from the outside of the cornea.
Results: :
This new technique improved the outcomes of the previously set one, which required the introduction of the fiber probe into the anterior chamber. Effective spot welding between donor endothelial flap and recipient stromal surfaces was achieved with 10-15 diode laser pulses of 75 mJ energy 0.15 s duration. Postoperative exams up to 6 months showed no postoperative displacement of the donor flap and average loss of endothelial cells of less than 20%.
Conclusions: :
The technique we set up showed: 1) good reproducibility and precision, thanks to the preparation of endothelial flaps of preset and constant thickness by the IntraLase®; 2) easy and safe irradiation from the outside of the cornea to perform diode laser spot welding; 3) reduced endothelial damage and good adhesion of the donor flap in the follow-up.
Clinical Trial: :
Prato Ethical Committee, N.o 4 of 22 March 2007
Keywords: cornea: endothelium • laser • transplantation