To perfect the technique of femtosecond laser-assisted cutting of the lamella r corneal disc in posterior lamellar keratoplasty. Experimental study. The femto second laser was used to make the posterior corneal lamell...To perfect the technique of femtosecond laser-assisted cutting of the lamella r corneal disc in posterior lamellar keratoplasty. Experimental study. The femto second laser was used to make the posterior corneal lamellar interface and treph ine (side) cut in 20 eye bank globes and 9 eye bank corneoscleral buttons. Laser parameters were energy 7.4±0.1 μJ (lamellar cut) and 8.7±0.1 μJ (trephinati on cut), spot size2.4 μm, firingrate 15kHz,and trephination diameter 6.0 to 8.0 mm. The thicknesses of the excised corneal discs were measured with a digital m icrometer and compared with values calculated from the laser treatment parameter s and the preoperative ultrasound pachymetric readings. The cut surfaces were ex amined by light microscopy and scanning electron microscopy. In globes, the corn eal disc was removed from the eye after laser treatment through a blade incision in the peripheral cornea. In corneoscleral buttons, the posterior disc was peel ed off the cornea with forceps after laser treatment on an artificial anterior c hamber device. In simulated transplantation, the excised corneal disc was placed into the posterior stromal bed in 7 globes. The femtosecond laser was successful in making posterior lame llar and trephination cuts in cornea. The cut surfaces were of very good quality with straight, orthogonal edges, albeit with a mild stucco texture of the lamel lar stromal surfaces. In 3 globes, the lamellar surface showed shallow concentri c ridges. The measured thickness of the excised discs was 55±61 μm thicker tha n the preoperatively predicted values. These preliminary studies show that the f emtosecond laser can make nonmechanical cuts for poste-rior lamellar keratoplas ty with relative ease and reliability, thus facilitating the most technically di fficult step in this surgery.展开更多
文摘To perfect the technique of femtosecond laser-assisted cutting of the lamella r corneal disc in posterior lamellar keratoplasty. Experimental study. The femto second laser was used to make the posterior corneal lamellar interface and treph ine (side) cut in 20 eye bank globes and 9 eye bank corneoscleral buttons. Laser parameters were energy 7.4±0.1 μJ (lamellar cut) and 8.7±0.1 μJ (trephinati on cut), spot size2.4 μm, firingrate 15kHz,and trephination diameter 6.0 to 8.0 mm. The thicknesses of the excised corneal discs were measured with a digital m icrometer and compared with values calculated from the laser treatment parameter s and the preoperative ultrasound pachymetric readings. The cut surfaces were ex amined by light microscopy and scanning electron microscopy. In globes, the corn eal disc was removed from the eye after laser treatment through a blade incision in the peripheral cornea. In corneoscleral buttons, the posterior disc was peel ed off the cornea with forceps after laser treatment on an artificial anterior c hamber device. In simulated transplantation, the excised corneal disc was placed into the posterior stromal bed in 7 globes. The femtosecond laser was successful in making posterior lame llar and trephination cuts in cornea. The cut surfaces were of very good quality with straight, orthogonal edges, albeit with a mild stucco texture of the lamel lar stromal surfaces. In 3 globes, the lamellar surface showed shallow concentri c ridges. The measured thickness of the excised discs was 55±61 μm thicker tha n the preoperatively predicted values. These preliminary studies show that the f emtosecond laser can make nonmechanical cuts for poste-rior lamellar keratoplas ty with relative ease and reliability, thus facilitating the most technically di fficult step in this surgery.
