Therapeutic Applications of the Femtosecond Laser in Corneal Surgery

Since 2001 the femtosecond laser has primarily been used in refractive surgery, e. g., for lasik, implantation of intracorneal ring segments or antiastigmatic corneal incisions. However, the femtosecond laser is more and more used for therapeutic reasons in corneal surgery. In this context it is used for profiled trephinations in penetrating keratoplasty where various profiles of the cutting edge can be designed (e. g., tophat profile, mushroom profile, zig-zag profile). The potential advantages of these profiles include improved graft adaptation, better and more stable wound healing leading to earlier suture removal and eventually prolonged graft survival. However, none of these potential advantages has been demonstrated by reliable study results until now. First clinical experiences show that much earlier suture removal is possible without significant complications. However, with sutures in there seems to be no advantage of the femtosecond laser compared to mechanically guided trephination systems regarding visual acuity and postoperative astigmatism. Besides penetrating profiles, the femtosecond laser also allows for lamellar cuts. As deep anterior lamellar keratoplasty can only be supported by the femtosecond laser, it is mostly used for posterior lamellar grafts in this context. However, first clinical results using the femtosecond laser for DSAEK (descemet stripping automated endothelial keratoplasty) are poorer than those using microkeratome-prepared lamellar grafts for DSAEK.