First application of laser welding in clinical transplantation of the cornea

Abstract

After a 4-year-long pre-clinical experimentation carried out at first on enucleated eyes and then on animal models, we applied a new procedure of laser welding of the cornea on voluntary patients. The welding technique is based on controlled irradiation of the cornea by diode laser radiation (805 nm) operating at low power (60-90 mW) in association with a photoenhancing chromophore applied locally. The welding effect is very effective and selective, because it takes place only in the cut where chromophore is present, while the contiguous tissue remains completely untouched. In the clinical phase, this technique was firstly tested in corneal cuts of increasing length on 25 patients subjected to facoemulsification of the cataract, by both sclero-corneal and corneal tunnels, and to extracapsular cataract extraction by sclero-corneal and corneal cuts. As previously confirmed by histological analysis performed on animal samples, we observed in humans too an early and effective healing process, with a sensible reduction of the post-operatory astigmatism. Based on these positive results, we finally arrived at the first application of diode laser- assisted corneal welding to penetrating keratoplasty (corneal transplantation), where this technique has been employed as far as now in 3 cases to substitute the application of the continuous suture.