Abstract
Purpose: :
To evaluate the feasibility of a new laser–assisted technique in lamellar keratoplasty (ALSL–LK), using the Intralase® femtosecond laser to prepare donor button and recipient corneal bed, and then suturing the edges of the wound by diode laser–induced corneal welding, without application of conventional suture material.
Methods: :
Based on our previous clinical experiences in penetrating keratoplasty, assisted by diode laser–induced suturing of the corneal wound, we designed a new application of this laser technique to lamellar keratoplasty performed by means of the Intralase® femtosecond laser. In a voluntary informed patient suffering from corneal leukoma, we used the Intralase® for the preparation of the donor corneal button (300 micron thick, 8.5 mm in diameter) and of the recipient bed. Then the surgical wound was sutured according to our laser technique, which consists of the preliminary application of a solution of Indocyanine Green (ICG) in the edges of the wound, followed by laser welding of the wound by means of diode laser irradiation at a wavelength of 810 nm, which corresponds to the optical absorption peak of ICG.
Results: :
Continuous wave diode laser power as low as 60–80 mW (corresponding to 84–113 W/cm2 at the output of the 300–micron–core laser fiber) and treatment time of 180 seconds were found to be suitable in order to provide effective corneal welding with good mechanical strength along the whole circumference of the wound. This positive result, together with the optimal correspondence between donor button and recipient bed geometries, as achieved using the Intralase®, supported our choice to avoid any further application of conventional suturing. Clinical examinations on 1, 3 and 30 post–operative days indicated: 1) formation of a smooth stromal interface, 2) total absence of edema, 3) complete re–absorption of ICG after 3 days, and 4) maximum post–operative astigmatism of 2.5 D, evaluated by corneal mapping.
Conclusions: :
The combination of Intralase® corneal lamellar trephination and diode laser–induced welding of the wound in ALSL–LK have significant potential advantages over conventional surgical methods of corneal lamellar transplantation. Further studies to verify our results are underway.
Keywords: laser • refractive surgery • wound healing