Abstract
Purpose: :
To evaluate improvements of a new laser-assisted technique in penetrating keratoplasty, using the IntraLase® femtosecond laser to prepare the donor and recipient cornea and the diode laser to promote wound healing.
Methods: :
In 10 volunteers suffering from keratoconus (IV s), the IntraLase® (60 kHz repetition rate) was used for the preparation of a donor button with a z shape external profile. In the recipient eye an identical cutting pattern was performed with the fs laser. The donor tissue was thus exactly inserted in the recipient eye. The donor flap was assured to the recipient eye by apposition of 8-16 separated stitches. Internal walls of the surgery wound (i.e. the stroma of both donor and recipient eye) were then stained with a water solution of Indocyanine Green (ICG) used as a photoenhancing chromophore, in order to perform tissue welding by continuous wave irradiation with a 810 nm diode laser (12 W/cm2 power density).
Results: :
This new technique improved the outcomes of the standard penetrating keratoplasty technique. The particular profile of the donor flap walls, that exactly matched the profile in the donor eye thanks to the cutting technique of the Intralase ®, assured good approximation and closure of the apposed margins, and a stable and controlled p.o. astigmatism (<3.5 d).
Conclusions: :
The technique we set up showed: 1) good reproducibility and precision, thanks to the preparation of donor and recipient flaps of preset profile and controllable thickness by the IntraLase®; 2) good adhesion of the donor flap at the time of surgery and in the follow-up, thanks to diode laser welding of the corneal wound.
Keywords: laser • keratoconus • astigmatism